Re: gEDA-user: OT: Bike Alarms (was: Re: Coppe r-free area in footprint )
On Thursday 13 May 2010, timecop wrote: Same as with the lights. Either from a dynamo, or from batteries charged at home. For bonus points, make it charge by induction while sitting inside the seat pole. An old Oral-B toothbrush, stripped and the coils re-adjusted, might be just the ticket. Also, for whoever suggested Ni-Cad instead, they also self discharge, needing topped up about monthly. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The following is not for the weak of heart or Fundamentalists. -- Dave Barry ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Database on symbols, footprints and other (was Re: gattrib)
On Thursday 06 May 2010, Dave McGuire wrote: On May 6, 2010, at 5:30 PM, Felipe De la Puente Christen wrote: Sometime ago I was thinking that gEDA-users as a comunity could request a part search API-like system to the distributors. For example,Digikey already has a fast-search bar for firefox, so they are not far from what I mean. But the useful way would be something like the GeoCode APIs available on the web. So the app can build a part search request from a set of string, and generate the url to get the answers. A solution like that would allow every EDA tool to implement multiple itneresting functions like purchase information from multiple distributors based on BOM info, and so on. I have the feeling that this could have good reception from companies like digikey, mouser, arrow... This would be wonderful, wonderful, WONDERFUL. It would ROCK. In case I'm being unclear, I think this is a great idea. And I like it. -Dave What he said, +100. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Q: How many psychiatrists does it take to change a light bulb? A: Only one, but it takes a long time, and the light bulb has to really want to change. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: A little puzzled about the purpose of gschem
On Thursday 29 April 2010, Dave McGuire wrote: On Apr 29, 2010, at 12:48 AM, Gene Heskett wrote: Well, you started out complaining about a 741 model. I'd call that a very rare, obsolete part: I haven't actually seen one in a circuit in over 30 years. I guess it's still in textbooks (read Stephen J. Gould's rants about textbook authors' tendency to copy from previous textbooks sometime), but why would anyone use it in a new design? Very rare?! I see 741s everywhere. WTF? Sorry to bust the bubble, but he's right. The 741 is well over 40 years old, and its open loop first response pole, where the 6db per octave rolloff begins, is a measly 10 hertz. Today there are $1.00 opamps with a working gain of 20 when feedback is applied, with output slew rates of several thousand volts per second. Thats working bandwidth to several hundred megahertz at the sort of levels found in either a modern broadcast audio mixer, or a production video switcher, and either of those are driving 60 ohms for audio, or 75 for video. Slew rate limits alone in the 741 means you can't honestly ask it for more than a volt of output at full audio bandwidth. At 3 volts the slew rate distortion is so bad even these 75 year old ears can hear it. Even a TLO-72 or 74 can mop the floor with a 741, and output a +- 15 volt rail to rail signal doing it, but into the old 600 ohm std load. No bubbles to bust, I'm not particularly fond of the 741...yes there are definitely better opamps out there (I usually use OP07s as my general-purpose opamp) but that doesn't change the fact that I see 741s everywhere. They are far (VERY far) from rare. -Dave At one point I had to replace some custom made on ceramic plates, op-amps in a Grass Valley 300-3A/B switcher, and GVG were being asses, wanting $1700 for one of them. I went to the catalogs found a to5 can that looked good, and put them into 3 failed channels of that production video switcher. They were so much faster, for $1.32 each, that it threw it out of color phase by about 10 degrees. If the removal and changeover hadn't been at least an hours work per channel, and I'd have had to replace about 48 of them all told, I would have. But we were then on notice that digital was coming, so that, originally $175,000 switcher was effectively in maintenance mode only. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Your happiness is intertwined with your outlook on life. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: A little puzzled about the purpose of gschem
On Thursday 29 April 2010, Russell Shaw wrote: Gene Heskett wrote: On Wednesday 28 April 2010, Dave McGuire wrote: On Apr 28, 2010, at 3:40 PM, John Doty wrote: Well, you started out complaining about a 741 model. I'd call that a very rare, obsolete part: I haven't actually seen one in a circuit in over 30 years. I guess it's still in textbooks (read Stephen J. Gould's rants about textbook authors' tendency to copy from previous textbooks sometime), but why would anyone use it in a new design? Very rare?! I see 741s everywhere. WTF? -Dave Sorry to bust the bubble, but he's right. The 741 is well over 40 years old, and its open loop first response pole, where the 6db per octave rolloff begins, is a measly 10 hertz. The opamp is 1MHz unity BW. The higher the gain, the lower the first pole. An even better opamp would roll off at 1Hz. Today there are $1.00 opamps with a working gain of 20 when feedback is applied, with output slew rates of several thousand volts per second. Thats working bandwidth to several hundred megahertz at the sort of levels found in either a modern broadcast audio mixer, or a production video switcher, and either of those are driving 60 ohms for audio, or 75 for video. Those are video buffers. They have much less closed-loop gain and inferior offset voltages. They're also noisy and are very prone to oscillation with any stray capacitance or with certain feedback resistors. I believe that to be an artifact of the GB product not being high enough in what was available, say back in LM-357 days. When I replaced some custom made discreet op-amps in that grass switcher with some fairly modern internally compensated ones with a GB of about 10Ghz, it was absolutely not a problem. They were the ideal block of gain dead stable despite a layout when being used to sub for something else, that would give a modern video engineer recurring nightmares. Flying leads up to an inch long just to reach the original plates mounting and connecting holes in the PCB. That had kludge written all over it, but it technically kicked ass compared to the much slower discreet versions grass wanted $1700/copy for. Slew rate limits alone in the 741 means you can't honestly ask it for more than a volt of output at full audio bandwidth. dV/dt = 2.pi.Vm at 20kHz and 1V/us, Vm=8Vpk quite ok for most apps below 5Vpk. At 3 volts the slew rate distortion is so bad even these 75 year old ears can hear it. Even a TLO-72 or 74 can mop the floor with a 741, and output a +- 15 volt rail to rail signal doing it, but into the old 600 ohm std load. LM741 has 1mV OS typical. TL072 is 3mV Can you hear 3mv dc? LM741 would be better than TL072 for control apps, and cheaper. Maybe so, but with 4 of then in a dip, and room for 22 cards in the cage, I used them in multi-tube quantities (5 per card, 22 cards) for utility audio DA's at WDTV-5 for nearly 20 years. Most failures were on longer output run circuits, and lightening related. When you have a 255 foot tower 30 feet out the back door, the emp pulse from a lightning strike is considerable, and tends to knock out the output stages. So I designed one with some to5 outputs to buffer the chip output, and they had an even shorter life plus they crowbared the whole cage supply when they failed, much more catastrophic in effect as that didn't just cost us one audio src, it took us off the air. The old favorite burn your fingers power hog op-amp, 5532 would fail at 20x that rate under the same conditions. In broadcast, you learn to use what gets the job done with audio performance that is adequate, and is the _most_ dependable. Getting rid of that last .001% of distortion is not a priority that even makes the list. However, 25volts p-p at 20 khz with no slew rate or cross-over discernible on a 100mhz scope, or at lower frequencies my ears could hear well was good enough for the girls I went with. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) dracus Ctrl+Option+Command + P + R Knghtbrd dracus - YE GODS! That's worse than EMACS! LauraDax hehehehe dracus don't ask what that does :P ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: A little puzzled about the purpose of gschem
On Thursday 29 April 2010, John Doty wrote: On Apr 29, 2010, at 6:50 AM, Russell Shaw wrote: Gene Heskett wrote: On Wednesday 28 April 2010, Dave McGuire wrote: On Apr 28, 2010, at 3:40 PM, John Doty wrote: Well, you started out complaining about a 741 model. I'd call that a very rare, obsolete part: I haven't actually seen one in a circuit in over 30 years. I guess it's still in textbooks (read Stephen J. Gould's rants about textbook authors' tendency to copy from previous textbooks sometime), but why would anyone use it in a new design? Very rare?! I see 741s everywhere. WTF? -Dave Sorry to bust the bubble, but he's right. The 741 is well over 40 years old, and its open loop first response pole, where the 6db per octave rolloff begins, is a measly 10 hertz. The opamp is 1MHz unity BW. The higher the gain, the lower the first pole. An even better opamp would roll off at 1Hz. Today there are $1.00 opamps with a working gain of 20 when feedback is applied, with output slew rates of several thousand volts per second. Thats working bandwidth to several hundred megahertz at the sort of levels found in either a modern broadcast audio mixer, or a production video switcher, and either of those are driving 60 ohms for audio, or 75 for video. Those are video buffers. They have much less closed-loop gain and inferior offset voltages. They're also noisy and are very prone to oscillation with any stray capacitance or with certain feedback resistors. Slew rate limits alone in the 741 means you can't honestly ask it for more than a volt of output at full audio bandwidth. dV/dt = 2.pi.Vm at 20kHz and 1V/us, Vm=8Vpk quite ok for most apps below 5Vpk. At 3 volts the slew rate distortion is so bad even these 75 year old ears can hear it. Even a TLO-72 or 74 can mop the floor with a 741, and output a +- 15 volt rail to rail signal doing it, but into the old 600 ohm std load. LM741 has 1mV OS typical. TL072 is 3mV LM741 would be better than TL072 for control apps, and cheaper. Yes, but there are much better devices for control apps than a 741, with its high power consumption, high bias current, and poor voltage ranges for common mode, output, and power. Indeed, there are so many that it's a pain to choose. What should I replace the obsolete OP220 with? What was it trying to do? That will have a heavy bearing on the replacement choice. Stepping back, this discussion reinforces the point I was trying to make. We frequently have newbies to gEDA complaining why doesn't gEDA support my common/standard needs straight out of installation?. But the universe here is large, and nobody sees more than a bit of it. What you see as essential depends on where you sit. When it comes to parts selection, Gene thinks audio/video because that's what he works with. You seem to be cost sensitive. I'm a scientific instrument designer: parts cost is usually a negligible part of the budget, but noise and power are a big deal. We look at this stuff different ways. Quite so John. In my case parts costs were escalated because Grass thought (erroneously) that they had us by the whole bag, not just the short hairs. So, not knowing any better, I just did it. With excellent results. We differ also in career outlooks I suspect John. You are no doubt, from what I've read on this list for quite some time, a 'papered' engineer, with a heavy background in the math involved and are quite capable to ripping some of my arguments to shreds. I OTOH, was a boy geek before the word was invented and quit school to go fix these newfangled tv's in '48. Math was not one of my strong points, I learned more about the higher functions from an early TI calculator purchase than I ever got in formal schooling. I have been making electrons do as they are told since, although at 75, not for a living anymore. Making the switch to broadcast engineering in the early 60's narrowed my field of view and allowed me to get a much more closeup view, which was helpful. That 'specialization' has allowed me to be fairly well paid as the CE for the last 26 years. It has also gotten me accused of walking on water a few times. ;-) Moving from parts selection to the broader issues of EDA, we again see a great deal of diversity. There really are no common/standard needs beyond the basics that gEDA does pretty well. If you believe that there are, I think you need to broaden your horizons. +1 gEDA's unique strength is that it supports that diversity well. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Mercury At that point it will compile, but segfault, as it should.. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin
Re: gEDA-user: A little puzzled about the purpose of gschem
On Wednesday 28 April 2010, Dave McGuire wrote: On Apr 28, 2010, at 3:40 PM, John Doty wrote: Well, you started out complaining about a 741 model. I'd call that a very rare, obsolete part: I haven't actually seen one in a circuit in over 30 years. I guess it's still in textbooks (read Stephen J. Gould's rants about textbook authors' tendency to copy from previous textbooks sometime), but why would anyone use it in a new design? Very rare?! I see 741s everywhere. WTF? -Dave Sorry to bust the bubble, but he's right. The 741 is well over 40 years old, and its open loop first response pole, where the 6db per octave rolloff begins, is a measly 10 hertz. Today there are $1.00 opamps with a working gain of 20 when feedback is applied, with output slew rates of several thousand volts per second. Thats working bandwidth to several hundred megahertz at the sort of levels found in either a modern broadcast audio mixer, or a production video switcher, and either of those are driving 60 ohms for audio, or 75 for video. Slew rate limits alone in the 741 means you can't honestly ask it for more than a volt of output at full audio bandwidth. At 3 volts the slew rate distortion is so bad even these 75 year old ears can hear it. Even a TLO-72 or 74 can mop the floor with a 741, and output a +- 15 volt rail to rail signal doing it, but into the old 600 ohm std load. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The only way for a reporter to look at a politician is down. -- H.L. Mencken ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gEDA/gaf release branch in git? mac build?
On Wednesday 31 March 2010, Peter TB Brett wrote: On Wednesday 31 March 2010 17:06:14 John Griessen wrote: Peter Clifton wrote: On Tue, 2010-03-30 at 15:41 -0700, Dave N6NZ wrote: I want to follow the git -- but for now on the release branch (if there is one??) not the dev head. Use the stable-1.6 branch in that case. Individual releases are tagged as well. What's the git command to list tags? What's a good write up of a short cheat sheet style list of commands for git? git probably has the most comprehensive set of manpages ever, BTW. :-P Peter Yes, they should have had Junio when they wrote the grub docs. Those have a 10-33 tor vacuum in them. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Plastic... Aluminum... These are the inheritors of the Universe! Flesh and Blood have had their day... and that day is past! -- Green Lantern Comics ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: if you people want to do it then put up the *cash*
On Monday 15 March 2010, John Griessen wrote: Ales Hvezda wrote: problem with for-pay servers is users are motivated, they help pay for a few months, then no more so any decisions that affect $$ need to account for probably Ales paying for it out of pocket I have absolutely no issues with removing me as a single point of failure, however, if you people want to do it then put up the *cash*, time, and get some buy-in from all people doing the development work. When my friends on the metalartists.org list lost the previous server and I started a mailman server for them they donated money via paypal to get to paid up for a year and a half after just a week. It might not be hard, even with this bunch to get virtual server money. For OpenVZ on Quantact.com servers you'd need to budget $30/month for the level of RAM needed to run mailman. These prices might even drop some as things progress, since some web hosters, (Network Solns), with canned web-app packages (not root accounts), now run at $11/month. I'm good for $20 for server support -- I expect that to go for a years worth after asking the rest of the people that care to contribute. So now the question is Who else will pledge money?. John I am just a lurker generally, but I think Ales has done a good job those times when I grabbed the next 'generation' of this stuff, it seems to have a minimum of the PIMA content most such projects seem to have an abundance of, with SF being the most prominent in my limited experience as I have repo write access there on one of the legacy computer OS projects it loves to forget my pw on a random basis. If Ales all vote to setup the NP thing, even if it still runs on Ales's servers and a few bucks a month is needed to compensate Ales (or whoever might succeed should something happen, then I am sure my card could get $20/year lighter for as long as I'm around. Just set it up and post the donate site URL here. However, since I'm both 75 and diabetic, I have no warranty of being here tomorrow, but today I'm good. Basically, somebody needs to pay the energy bill in any event. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) I hate mankind, for I think myself one of the best of them, and I know how bad I am. -- Samuel Johnson ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: TO-92 Best Practices
On Wednesday 03 March 2010, Larry Doolittle wrote: Al - On Wed, Mar 03, 2010 at 10:18:59AM -0500, al davis wrote: Along that line ... You could get what they call reading glasses from a supermarket. Get the strongest ones they have. They make great magnifying glasses. I didn't need them in college, but I sure need them now! You really should wear eye protection while soldering anyway. Right. Funny story. We had a big safety audit here a few months ago. Lots of new work practices, including mandated eye protection -- safety glasses -- when soldering. So .. I start doing some rework on a particularly tricky section of an 0603-scale board. A flock of managers cruised by and said -- Hey! you don't have safety glasses on! I show them that I don't get any benefit from safety glasses when I'm soldering under a 10X microscope. - Larry Nice, if there is room for the microscope, the soldering iron and the solder, all in the field of view. Panasonic, 10 years ago, didn't succeed in doing that, so I was stuck using about a 6 magnifying lens, in a parallelogram suspension system, with the smallest circular hot cathode fl lamp wrapped around it. Mostly replacing bypass caps on digital boards, using a GC 'tweezer' style double soldering iron plugged into a powerstat and turned down to about 60 volts to control the temp. These caps were surface mounted, and crap. The size of a lead pencil eraser and smaller, I started dumping the old ones into a 3 pound coffee can thinking they might be recyclable alu at some point. By the time I'd retired, we had the 3rd can started... Panasonic of course made their own caps, and few if any of the quality replacements could be parked on their footprint, so it was a severe stretching of the definition to call 30 hours a week doing that 'fun'. I get a back ache between my shoulder blades from hunching up to that glass just thinking about it. But when the alternative is replacement boards from the Russian Mafia in New Jersey at many hundreds each, or replace the $4k to $13k machine at 6 month intervals, it only had up to 27 such boards in it. Their tech in the New Jersey shop was a guy named Alex, from Russia, and it wasn't unusual to bypass the phone menu by saving time asking to for the 'Russian Mafia', it was simpler than trying to figure how to pronounce his last name using an accent the New Jersey girls understood. They had more than one Alex it seemed. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Typo in the code ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gedasymbols.org down
On Friday 26 February 2010, Bob Paddock wrote: On Fri, Feb 26, 2010 at 9:49 AM, Kai-Martin Knaak k...@familieknaak.de wrote: gedasymbols.org seems non responsive at the moment. Any hint for a reason? http://kdka.com/topstories/Northeast.snow.storm.2.1522070.html Good luck with that Bob, I have another 10 of white stuff here since this time yesterday, and I'm in north central WV. And still coming down at an inch plus an hour. KDKA is about 130 miles north of me. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Windows 2000 will be released as soon as Windows 98 finishes loading. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: FIRST robotics...
On Wednesday 17 February 2010, DJ Delorie wrote: Some of you know I've been working with the local high school's FIRST robotics team. Here's a status update: http://www.youtube.com/watch?v=3_VfT5_mEn0 At 0:49 there's a photo of me teaching one of the freshman how to assemble a circuit board full of 0603's and PTH parts. The board was designed with gEDA/PCB, etched in my basement, built my him, and works like a charm. And no, I did not have to fix *any* of his soldering. The board is a manual servo controller, or servo tool. Since I didn't have any 555's kicking around, it instead has a 16-bit microcontroller that makes the pulses and drives an LED array. D.J.D.; The rating I would apply to any teaching effort is whether or not the project works. It looks like you have succeeded very well. I believe this makes a lie out of the old saw about 'those who can't, teach'. For instilling in these young folks, a sense of pride in laying it out and doing it right, we need a squad of cheerleaders to put on a show but I'm fresh out of those. But, if you are anything at all like me, having the project work at all, let alone look that professionally built, would make me very proud of myself as well as giving me some better ideas for the next years classes. And proud is what I think you should be. Pride in what one has done well is a reward in and of itself. But I suspect you already knew that. Congratulations are in order, and here are mine. Thank you for posting the link. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) I didn't order any WOO-WOO ... Maybe a YUBBA ... But no WOO-WOO! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: FIRST robotics...
On Wednesday 17 February 2010, DJ Delorie wrote: D.J.D.; For those who don't know - DJ is my name, not my initials. Oops, sorry. I didn't do that intentionally, I just assumed that the DJ was for David James or some such. My apologies. For instilling in these young folks, a sense of pride in laying it out and doing it right, we need a squad of cheerleaders to put on a show but I'm fresh out of those. I think that's the whole point of FIRST - For Inspiration and Recognition of Science and Technology. We mentors are now starting to think about what to do in the off season to (1) keep the kids interested, and (2) show the rest of the school what we're up to. I've suggested robot mascots at the football games :-) I think that's a jolly idea. Not only does the programming and inevitable maintenance teach them even more, but it shows off the talents of both you and the kids, in front of a whole grandstand full of frogs. There will be those who downplay it as wasting the schools money, but those same people have probably voted against any excess school tax levies since they were old enough to buy beer. Hell, I may be 75 and fading, but dammit folks that's the best tax money I ever paid. If it makes the diff between a productive adult, and one who is so poorly trained to do anything that he's a regular customer at the county jail, it is worth it. Same scene, if it heads off one bored troublemaker, that is another point of pride. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The trouble with heart disease is that the first symptom is often hard to deal with: death. -- Michael Phelps ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OT?] Circuit Cellar Magazine Sold to Elektor
On Tuesday 08 December 2009, Bob Paddock wrote: As gEDA and DJ have been feathered in Circuit Cellar Magazine, Feathered? I hope not with tar too. ;) I thought I'd mention the news that Circuit Cellar Magazine being sold to Elektor. http://www.elektor.com/news/big-deal-elektor-circuit-cellar.1175563.lynkx http://www.circuitcellar.com/archives/priorityinterrupt/234.html As a long term subscriber to CC, and a long time fan of Steve C., going clear back to the original Byte magazine, I sincerely hope that this allows Steve to continue to opine on things electronic. In my private conversations with him, I have found an about as down to earth a personality as you could imagine. I really do hope this works for both. Retiring on your own terms is the best one can hope for, and this sounds as if he won't actually be disappearing for a long time. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Even if you do learn to speak correct English, whom are you going to speak it to? -- Clarence Darrow ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: .pcb question
Greetings; Does geda have a .pcb file viewer, such as is output by the ExpressPCB free software for windows? I've got a small tabletop milling machine, and have been asked to do a board that is about half the size of a postage stamp. And, if so, can it convert a .pcb into a couple of .ngc's for feeding a milling machine, one for each side of the board? Thanks all. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Take an astronaut to launch. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: .pcb question
On Sunday 25 October 2009, Peter Clifton wrote: On Sun, 2009-10-25 at 07:55 -0400, Gene Heskett wrote: Greetings; Does geda have a .pcb file viewer, such as is output by the ExpressPCB free software for windows? I've got a small tabletop milling machine, and have been asked to do a board that is about half the size of a postage stamp. No viewer.. just .pcb. Are you looking for a linux / windows version? linux if possible, I am not a wine expert, and the only windows here are made out of real glass. :) (PCB has a windows installer available on sourceforge.net). And, if so, can it convert a .pcb into a couple of .ngc's for feeding a milling machine, one for each side of the board? The nearest it outputs is gerber - for photoplotters. That won't be what you need to drive a mill. You need something like: https://sourceforge.net/projects/gerbertogcode/ Well, if this 'PCB' can output gerbers, I'll give the above a look. But I've never tried it, so don't know how (well) it works. It lists as alpha on sourceforge, so might be somewhat buggy. Something I might be able to contribute to if I knew gerber's code as I am moderately familiar with .ngc code. Best wishes, Peter C. Thank you very much Peter. When I have something usable, I'll report back if CRS doesn't get to me. Considering the years on the carcass here, 75, that is a possibility. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp You will have a long and boring life. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: .pcb viewer
On Sunday 25 October 2009, Harry Eaton wrote: Does geda have a .pcb file viewer, such as is output by the ExpressPCB free software for windows? I've got a small tabletop milling machine, and have been asked to do a board that is about half the size of a postage stamp. And, if so, can it convert a .pcb into a couple of .ngc's for feeding a milling machine, one for each side of the board? I think there may be some misunderstanding what you are asking here. I interpret your question to be The windows program ExpressPCB has created a .pcb file. Does geda have a viewer for this file? Now I don't know anything about ExpressPCB, but it probably creates files in its own (probably proprietary) format and gives them a .pcb suffix. Geda has a program for designing boards called pcb, and it is common practice to use a .pcb suffix for files it produces in its (open) native format. It is highly unlikely that there is any reasonable similarirty between the two file formats. So if you have a design created with ExpressPCB that you want to work with, I think Peter's answer won't help you. You could instead redesign the board using geda's pcb (I can't believe I typed that) and then use Peter's suggestions. And what is the pcb designers cli name? I think I have all of the geda suite installed, but there is not a pcb designer in the electronics menu. Only gerbview, gshem and gattrib seem to have been installed into the menu's. F10 system here, on a quad core phenom, 4GB of ram, 2.x terrabytes of drives. . Cheers, harry ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp No matter how subtle the wizard, a knife in the shoulder blades will seriously cramp his style. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: .pcb question
On Sunday 25 October 2009, John Luciani wrote: There is a python script, from the MIT Media Lab, that converts Gerber files into a format used by a Roland milling machine. The python script is at http://web.media.mit.edu/~neilg/fab/dist/cam.py And massaging that to output RS-274-D stuff might teach me some python, if that is doable for me. New stuff seems to be getting more difficult all the time as half my 7nth decade has rolled on by now. I am not sure if the Roland uses NGC or some other format. The commands looked a lot plotter control commands to me. Me either, but since its Roland, I'd have to assume its closed. The only Roland machines I've seen recently are a pair of graphic plastic sheet cutters, to make huge signs and such with. One of my neighbors is in that business. No idea if its close enough to English to translate easily, and since he does all the composition with a Roland supplied windows application, I have doubts he has ever actually looked at the code going down the cable. I brought a couple of Gerber files to try routing a board using the milling machine. Unfortunately the CAM program they have only understands a subset of the Gerber specification, specifically the subset that Eagle outputs :( Ouch, and my copy of eagle-lite likely doesn't even export gerbers. It will not load this file, no errors because no attempt to load it is made. :( (* jcl *) Thanks. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp If you want to travel around the world and be invited to speak at a lot of different places, just write a Unix operating system. -- Linus Torvalds ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: .pcb viewer
On Sunday 25 October 2009, Peter Clifton wrote: On Sun, 2009-10-25 at 11:25 -0400, Harry Eaton wrote: Does geda have a .pcb file viewer, such as is output by the ExpressPCB free software for windows? I've got a small tabletop milling machine, and have been asked to do a board that is about half the size of a postage stamp. And, if so, can it convert a .pcb into a couple of .ngc's for feeding a milling machine, one for each side of the board? I think there may be some misunderstanding what you are asking here. I interpret your question to be The windows program ExpressPCB has created a .pcb file. Does geda have a viewer for this file? Ah - looks like I misread the question. Now I don't know anything about ExpressPCB, but it probably creates files in its own (probably proprietary) format and gives them a .pcb suffix. IIRC, it is a vendor lock-in design program for their fab, so there is no way to export from it, not even gerbers. http://www.expresspcb.com/ Sorry! Copy that, loud and clear. :( Like Harry said, re-designing the board in (gEDA) PCB would be the only option here, but I'm not 100% convinced about the output to mill commands anyway. Best test that bit first before investing too much time in re-designing the board! Well, I told him early this morning that he would probably be better off just having it setup about 20x up on ExpressPCB's smallest double sided board, which for a potential market of maybe 150 copies, can be done 50x faster and cheaper by the time I invest in those teeny ex$pensive carbide bits. Because my spindle is maxed at 2500 rpms, I'd have to use F speeds similar to watching the paints we had 75 years ago dry. No profit, other than the entry on the resume in taking 1 to 4 hours for each side of a board that's half a postage stamp in size IMO. And at my age, I'd do it just for the grins if the code conversions were 1/1, that is a much larger problem than the extreme prices for the bits I believe. If the board's designer can take a screen-shot from express-pcb (perhaps one on each layer), you can import the screen-shot as a background to trace over in PCB. That I can do with screen captures and gimp to trim to size from the running wine version. (Just a note.. the PCB+GL branch _can not_ render background images). Best wishes, Peter C. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp IN MY OPINION anyone interested in improving himself should not rule out becoming pure energy. -- Jack Handley, The New Mexican, 1988. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: .pcb viewer
On Sunday 25 October 2009, Peter Clifton wrote: On Sun, 2009-10-25 at 13:04 -0400, Gene Heskett wrote: And what is the pcb designers cli name? Just pcb. I think I have all of the geda suite installed, but there is not a pcb designer in the electronics menu. Only gerbview, gshem and gattrib seem to have been installed into the menu's. F10 system here, on a quad core phenom, 4GB of ram, 2.x terrabytes of drives. gEDA and PCB are technically separate projects, so it might not be installed. Try yum install pcb Got that, seems to work, but claims this file is an illegal format, confirming the vendor lockin (spit) of the ExpressPCB program. Best wishes, Thanks peter. I've not heard back from Roger, so maybe he is taking my advice. TBT, there is no money in doing it, it is an adapter board that allows other storage devices to be plugged into the same socket an EB-101 plugs into to put a working bluetooth serial port on a 22 year old computer. He will be lucky to recoup his expenses. Its like climbing a mountain, because its there. :-) Peter C. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp If I can have honesty, it's easier to overlook mistakes. -- Kirk, Space Seed, stardate 3141.9 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Eliminate separate Vcc planes?
On Monday 19 October 2009, Bob Paddock wrote: Boss just sent around something he got from a consultant on doing proper EMI design (which I've been doing for years already, I thought until consultant came up with this): Eliminate separate Vcc planes. What's he/she smoking, it must be great stuff and I want a sample. This ancient practice is long overdue for an overhaul. Years ago, the leaded capacitors were not able to provide a good enough short at VHF and above, so the reasoning was that the parallel plates of Vcc and ground made a good UHF capacitor. The problem with this is twofold: it takes away one or more ground planes, and more importantly doesn’t allow the designer to control where the noise current goes. Noise follows the path of least impedance, which may be anywhere on the PCB after you punch holes in the Vcc plane for vias and to route traces that have no other room to go. The best way to control noise is to use a separate trace for Vcc, and apply series and shunt elements to control the noise currents. There is no attribution as to were that advice comes from. And as a C.E.T. with 60 years of electronics experience, troubleshooting to the part level, I sure as heck would not want my name attached to such advice. The frequencies in question are 400 MHz to 3 GHz. To me running Vcc traces all over the board is the surest way to raise inductance etc., and seems wrong to me. It is. But it is sometimes helpful to make those layers a bit like a star topology to help steer the noise properly and keep it from going willy-nilly anyplace it wants to go. Want to know what you thought of this consultants advice? Rubbish. Whats worse is that your boss probably _paid_ for that advice. Doesn't cover what happens in multi-rail systems either. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp The law will never make men free; it is men who have got to make the law free. -- Henry David Thoreau ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Eliminate separate Vcc planes?
On Monday 19 October 2009, Dan McMahill wrote: Larry Doolittle wrote: Good RF decoupling standard practice is to use a smaller cap (e.g. 20pF in parallel with some larger ones such as 1000pF _and_ 0.1uF or larger as needed) to get a good broad band capacitive reactance across frequency). I have yet to see a 20pF or 1000pF cap with less parasitic inductance than a decent (e.g., X5R) 0402 cap up in the uF range. Say, in particular, TaiyoYuden JMK105BJ225MV-F 2.2uF 0402 6.3V X5R 0.1560 in 100's If you're going to occupy board area with a cap and its connection to the power nets, can anyone explain why I should choose anything other than the largest value available in that size and voltage? my recent experiences are more in line with Larry's. Most C for a given package and voltage seems to be the best meaning that above resonance it is no worse than smaller capacitance value devices and below resonance it is better. And yes, this seems to fly in the face of what has been recommended in the past. I've not done any careful measurements of older technology bypass caps but I wonder if this is one of those rules which became obsolete 15-20 years ago and no one noticed... -Dan It may have, having been replaced with surface mounted, there leadless packages. Unforch, the traces leading to the pads then become the leads, so I have doubts one is completely home free with that approach. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp doogie netgod: 8:42pm is not late. netgod doogie: its 2:42am in Joeyland -- #Debian ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: pcb via and ground planes
On Friday 25 September 2009, gene glick wrote: DJ Delorie wrote: I talked with Dan about it, we seem to think it's better to not use the ground plane for the return signal, and route the return the same way you route the audio. Think of it like a differential pair. That way, you get current balancing without breaking up your ground plane. Also, avoiding vias helps ;-) You know what? There's merit to this approach - thanks for the idea! Lots of merit, based on my experience as a broadcast engineer trying to get poorly designed stuff to perform as the chip books spec say it should. Doing this encourages the emphasis in the star ground topology. The nearby ground plane should help to reduce induced noises unless there is a heavy power stage also making that ground plane bounce around. A very good idea indeed. After thinking about it a bunch, this may work out fine. It's definitely not what I originally envisioned. The only 'trick' here, when running those differential pairs, is to be certain the return current actually flows in them and not the planes. One should not allow a connection between your 'ground' run and the ground plane except at one common point for all such runs. I have all the wiring for my emc driven, stepper motor moved milling machine setup that way including shielded motor leads, grounded at one end only, and I can even do electro discharge machining with it, using an 80 volt supply at about 4 amps with a 10 uf oil in a can paper capacitor, loud enough to make your ears ring if you get too close to it, but it never lost or gained a step in a rather lengthy session of drilling holes with it a few months back. Sweet holes too, absolutely burr less. -- Cheers, From another Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Why use Windows, since there is a door? ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Slightly OT: Premier Farnell buys Cadsoft (Eagle)
On Thursday 24 September 2009, Gareth Edwards wrote: http://www.electronicsweekly.com/Articles/2009/09/24/47028/premier-farnell- buys-design-software-firm-cadsoft.htm I wonder what this will do to the freebie download that lets us all look at eagle files. That has come in handier than bottled beer on many ocasions here. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Kids, don't gross me off ... Adventures with MENTAL HYGIENE can be carried too FAR! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gEDA just hit SlashDotOrg
On Monday 03 August 2009, John Doty wrote: On Aug 2, 2009, at 5:20 PM, Bill Gatliff wrote: One of the ways that the gdb guys cracked this nut was to push a lot of their functionality into libraries, and create an HID-centric API for them. They include a command-line-interface implementation by default, but then others can take those same libraries and build their own GUIs around them. And drag in libraries from other places to add functionality that gdb doesn't itself provide. So now Eclipse, DDD, Insight, and many other frontends can all use the same gdb backend rather than inventing their own. Everybody wins. For one of my space missions, we had a company write much of the software. They were really big on IDE's with interactive debugging. But there was part of the system that was buried in a way that made it inaccessible to the interactive debugger. They complained bitterly about this, but there was no practical alternative. But when it came to do the work, the guy who had to suffer without the interactive debugger was consistently ahead of schedule, and produced software that was nearly bug free. The other programmers were chronically behind, and their software was infested with serious bugs. I visited their shop, and what I saw was disturbing: programmers stepping through buggy code hour after hour. But the guy who couldn't do that had a much higher productivity flow: unit tests, defensive coding, etc. took more thought up front, but they saved time in the end. The term fritterware comes to mind. Fritterware is easy to get started with, comfortable, addictive, and ineffective at doing the job (although not ineffective enough that its users notice). It sells well, and its users believe its bad characteristics to be essential. Interactive debuggers like gdb are fritterware. In ordinary environments, gdb's only genuinely useful command is bt. In embedded environments there are a few more. But all the massive complexity of stepping, breakpoints, etc. is pure fritter, suppressing thought and wasting time. Putting a GUI atop something that's already fritterware is harmless. Putting a GUI atop a graphical application is a good thing. Putting a GUI atop a complex, poorly factored (or intrinsically unfactorable) tool can help the user navigate the mess. But one should strive for an effective, cleanly factored toolkit that doesn't need a GUI except where real time interaction with the user is unavoidable. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com Pay attention to John, he _does_ know what he is talking about, I too have been that 'crippled' programmer. The only debugging tool worth anything on that platform was a register dumper that you could put a call to anyplace in your code. I was working on a swiss army knife sort of a file utility for that os, and when I was finished, and those calls removed and the code re- assembled, I posted the final version about an hour later. A decade plus later, that code is still being shipped. The only bug possible is PEBKAC even that is difficult to do. In that same decade change, I have yet to have anyone contact me about it not doing what it was supposed to do. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp The end of the human race will be that it will eventually die of civilization. -- Ralph Waldo Emerson ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Saturday 23 May 2009, Joerg wrote: Gene Heskett wrote: On Friday 22 May 2009, Joerg wrote: John Doty wrote: On May 21, 2009, at 6:00 PM, Joerg wrote: Chris Albertson wrote: [...] I'm thinking about tube amps that had an output impedance of about 1M ohm that used transformers to drive 8 ohm speakers. About a 100,000 to 1 ratio. 1M? What kind of tube was that? Well, that's a typical plate resistance for a small signal pentode, but Power pentodes have lower plate resistance. Small signal, yes. But a 12AX7 won't be enough for a rock concert ;-) And its not even a pentode, its a dual triode, designed for phono preamps and such. Sorry, I meant something like the 6AU6. Which fits the general thread idea a lot better. To me, a 6AU6 is a newer tube. 6SJ/K7's are middle aged, and the 4X's were popular for small signal 2A3's for audio output's about the time I was born. And all are transconductance pikers compared to a 7788. :) And my spell checker does not even recognize the word! -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Remember: Silly is a state of Mind, Stupid is a way of Life. -- Dave Butler ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Saturday 23 May 2009, Joerg wrote: Gene Heskett wrote: On Friday 22 May 2009, Joerg wrote: I'll second that. Did it in Spain but the track owner from whom I also rented the go-kart didn't want me on there anymore after my power-slides blew out the 2nd tire (including some smoke plumes). They must be rather expensive. 40 years ago, those slicks were about a $30 bill ea. So today, probably $75, 90 maybe? I haven't kept up. Shame on me. But I never blew one. My only failures were related to spinning the wheel in them, peeling the valve core out of the innertube. I don't know much about tires but what happened was that while the surface seemed to smoke the blow-outs happened on the sides of the tires. Both times it was the right rear. And in Spain $30 back then was a whole lotta dough. Probably was. ISTR I was making about $90/week back then. So I made those 2 tires run for 3 seasons worth of some dirt, some blacktop racing, never for more than a case of pop to the winners. But it was the ultimate fun for me at the time. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Never eat more than you can lift. -- Miss Piggy ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Saturday 23 May 2009, John Doty wrote: On May 23, 2009, at 7:56 PM, Gene Heskett wrote: To me, a 6AU6 is a newer tube. 6SJ/K7's are middle aged, and the 4X's were popular for small signal 2A3's for audio output's about the time I was born. And all are transconductance pikers compared to a 7788. :) And my spell checker does not even recognize the word! Not much excuse for a spell checker that doesn't know transconductance. Now, if it didn't know perveance I might be inclined to cut it some slack... ;-) Chuckle, tell that to the Aspell folks, John. And I'm not so sure I wouldn't fuss just as loud over perveance, and darned if it isn't fussing about that too. Sigh... John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp For most men life is a search for the proper manila envelope in which to get themselves filed. -- Clifton Fadiman ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Friday 22 May 2009, Joerg wrote: John Doty wrote: On May 21, 2009, at 6:00 PM, Joerg wrote: Chris Albertson wrote: [...] I'm thinking about tube amps that had an output impedance of about 1M ohm that used transformers to drive 8 ohm speakers. About a 100,000 to 1 ratio. 1M? What kind of tube was that? Well, that's a typical plate resistance for a small signal pentode, but Power pentodes have lower plate resistance. Small signal, yes. But a 12AX7 won't be enough for a rock concert ;-) And its not even a pentode, its a dual triode, designed for phono preamps and such. For a large signal amplifier, the load generally isn't matched to the output resistance. Instead, it's roughly (peak output voltage)/(peak output current), which is different. If you match the output resistance, in most cases you'll clip at an output power well below the capacity of the amplifier. And finally, the real issue here is the current required. 100 amps will melt the wire in any audio transformer I've ever seen. Everybody seems to think Mark's soldering gun suggestion is a joke, but I don't know. I think I'd get one, pull the transformer, measure its characteristics, see if it might work (maybe a couple of them in series/parallel or something). They're light, cheap, and the closest thing to the requirement here I can think of. I'm sure they won't run at full power all day without overheating, but for a test set that might be OK. Full power? A minute thirty maybe then needs at least a 5 minute cooldown. It's not a joke, quite viable maybe. But the solder guns I have used can't quite get to 100 amps. Maybe the 100W Weller I got for a client does, it cost around $30 at a hardware store. Another option is to use a regular (fat) mains transformer that has a bit of clearance between the packet and core. Run a wide sheet of thick copper through there, only one turn and leave its usual secondary winding alone. Or if to be driven from a generator drive that other secondary and leave the primary alone (and don't touch it ...). This results in a huge current capability. Another option may be welding transformers. Even my cheap one can deliver 160 amps for quite some time. But those are huge. As usual, Levente needs to take every piece of metal off. Wedding band, wrist watch, etc. Best not to have credit cards close by either because their magnetic strip might later be stripped of its information. BTDT, quite embarrassing when you take the guys out for lunch and the waitress comes back with Your credit card doesn't work. :-) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Life is a whim of several billion cells to be you for a while. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Friday 22 May 2009, Joerg wrote: I'll second that. Did it in Spain but the track owner from whom I also rented the go-kart didn't want me on there anymore after my power-slides blew out the 2nd tire (including some smoke plumes). They must be rather expensive. 40 years ago, those slicks were about a $30 bill ea. So today, probably $75, 90 maybe? I haven't kept up. Shame on me. But I never blew one. My only failures were related to spinning the wheel in them, peeling the valve core out of the innertube. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Complex system: One with real problems and imaginary profits. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Thursday 21 May 2009, DJ Delorie wrote: I'd kill 2 birds then, and grab a lawn chair and a beer, and sit beside it while its running long enough to run out of beer. :) Or just ask Pat to listen for it. She sits out there a lot - the A/C is next to the screen porch. Chuckle, passing the buck. :) Love it. But that would work if she can separate the sound of the compressor from the sound of the fan. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Quantum Mechanics is God's version of Trust me. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Thursday 21 May 2009, Joerg wrote: Gene Heskett wrote: [...] But I can't really bleed off freon. Plus AFAIK they don't sell that stuff to ordinary folk anymore unless you have a contractor's license. I mean, I could get one, but that would go a bit far ;-) Its no better on this side of the pond either, Joerg. ... It think we are on the same side of the pond. Well, maybe the other pond (I am in California). Oh, my mistake, I'm back here in the hills hollers of West (by God) Virginia. ... I stocked up on the auto stuff 20 years ago when the handwriting was on the wall I may have a 1 pound can in the basement yet that hasn't been tapped. ... That can could be worth a whole lot of money these days. To me maybe. I don't think I could legally sell it. ... My AC gages have R-134 scales on them, but the hoses can't take the R-134 pressures. I'm not sure, but I think my oldest vehicle (a 99 GMC 3 door, 4wd) now has R-134 in it, and its working poorly, so I'll have to bite the bullet and get it serviced before warm weather sets in for the summer. Ditto for the wifes VW Jetta, a 2002, but I have come to expect that, that Jetta was a lemon from the gitgo, costing the dealer I bought it from almost $2500 in body electrics within the 90 day warranty he gave me. Both front door window motors failed ($400 ea) and the motorized skylight ($1600) fell out! And I still have a laundry list of things that don't work right, like the passenger side seat heat, the radio, and the inability to aim the OEM but aftermarket Helia headlights in it, they are too low by about 5 degrees when cranked as high as I can get them. The OEM's were the usual sandblasted yellow sitting on the lot, and new ones, one of which has already burned up its internal wiring been replaced for gratis, were part of the purchase deal. And it still has only 20% of the lights my GMC has, that thing can see through a 2 course brick wall with its 10 year old, stock, original headlights yet! Fresh lamps of course, but still, they haven't yellowed a bit. Whatever kind of plastic they are made of, its the Right Stuff(TM). Ya win some, and ya lose some. :) Ouch. Sad actually. I've had an Audi station wagon in Europe, same mfg family. But I always try to buy the vehicle with the least amount of electrics/electronics because automotive guys don't seem to master this field all that well. The Audi still runs just fine over there, 21 years old, no issues in all those years. Yeah, I have a friend that drives them. Did have a black one when I met him in the early 80's, finally got a new one a couple of years ago that was light tan. I ribbed him about how much the paint job cost cuz there wasn't that much diff in the cars appearance. He said about 30 large. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Never make any mistaeks. -- Anonymous, in a mail discussion about to a kernel bug report ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Thursday 21 May 2009, Joerg wrote: [...] Wow, I've never been in a close call like that one. Only once in a small Dornier aircraft when the (otherwise totally quiet) bush pilot kind of guy let off a lot of cuss words, the stall horn was blaring, pine tree tops came at us and it was of course not high enough to do a parachute bail. A burly mtorcycle guy next to me who usually isn't afraid of anything mumbled Well, I guess this is it. We made it but could see the snow flying off the trees as we inched up in altitude. Maybe the newly found ground effect or something saved us. For a while there the tree tops looked like the road does from the low seats of a Porsche. Humm, similar I suppose to a go-kart I once had. Quite a rush when the blacktop is going by your hip joints at 120+mph, an only an inch below them. That of course was back in the 60's when go-kart engines were 2 strokers and some could make 4 to 5 horse per cubic inch. Mine was an old outboard, 14ci, but a deflector head design so even on booze it was only maybe 2hp/ci, and about 1 on straight gas. But that was enough to get the job done for me. :) I highly recommend that everyone who really wants to learn to drive, do it on an old go-kart, the new 4 strokers aren't fast enough by any means. On a go- kart you can play with the envelope and find out what the machine can do, generally without collecting any broken momentos. Lose it in the corner and spin it out? Go do it again, till you can hit that corner 30mph faster than when you spun out, steer it with the throttle while sliding at a 10 degree angle to the direction you are going, using every inch of the track just like the indy cars do. Spend a summer or 3 doing that and I guarantee you will never, ever drive a cage in such a manner that you can't handle whatever the road or weather throws at you. Even at my age, 74, I still have one corner I use as a gauge to see how I'm doing. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Being disintegrated makes me ve-ry an-gry! huff, huff ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, Steve Underwood wrote: Levente wrote: Hi, I have to design an audio amplifier that can deliver 100Amps. It should work around 50Hz, and the maximum output power shall be 500W. I am currently reading articles about this topic, but it is very hard to find things like this. If someone has some experience with, or some documentation of high current amplifiers, please share it. If you search the class-D power amp modules available for the audio market I think you may find what you need off the shelf. Steve Yeah, I did a quick google search, and 500 watts can be had for less than a C note from several places. The class D chip business has converted what was a $3000 amp into the sub $100 category in the last couple of years. I don't believe it would pay one to do a design from scratch today, its already done. Think car audio, where speaker impedance choices are 4, 2 and 1 ohm. And they wire everything with 4/0 cabling. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp A formal parsing algorithm should not always be used. -- D. Gries ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, Joerg wrote: DJ Delorie wrote: Levente Kovacs leventel...@gmail.com writes: 230V times 100A is something I dont want to even calculate. It's 23000 :-) My air conditioner draws 123 amps at 240 volts for the first few seconds. That's almost 30kW. Seconds and not fractions or a second? Yikes! Unless it's a 10-15 ton unit that doesn't sound normal. Did you find some of the power hogs with your new board by now? Off topic reply, but could be germain too. Not even a 40 horse compressor in a 22 ton (rated, yeah sure) Lennox will draw that much for that long. Its startup was a peak in the 250 amps/phase area, and the reason I say area is that a std 400 amp scale on an amp-probe on any phase line swung up to 250 and back down to its running of about 39 amps/phase in a purely ballistic fashion as the startup surge was only 6 or 7 cycles of the 208/3 phase line. Now it really gets off-topic. That was one of those _must_ _work_ units else a tv station was off the air 10 (or less) minutes after it failed. It was also probably responsible for some of the early ozone holes over the antarctic as it was severely under fanned on the condensor side, and I had to add 20 pounds of freon in the fall to keep it working right until it wasn't needed, and bleed that 20 pounds back off as spring turned into summer. This went on for 8 years on my watch, back in the 70's, and long before they started regulating all that stuff. 2 ea. 1100rpm 1/2 horse motors turning 24 fans just didn't cut it. I got tired of that one spring and fixed _some_ of it by taking a failed motor to town, having the brackets stretched to carry 2 horse 1800 rpm motors, replacing the motor with a 2 horse 1800 and repeating it the next week with the second one. 2 horse wasn't quite enough as they ran a couple of amps over nameplate when the condensor was relatively clean. When those blades failed (fatigue cracks, caught before they made shrapnel), I replaced them with blades with an inch less pitch. That allowed it to continue to work until the ambient went over 80 degrees without bleeding freon to keep the high side under 400 psi and the compressor currents under 43 amps/phase else the overcurrents in the compressor would trip. Based on those results, I would have said that a single 20hp motor, running at full load pulling a quad torrington wheel with each half about 16 wide 14 diameter, would have been about right. That could have been throttled with a 4' square louver driven by a M-H proportional control Modutrol to regulate the high side pressures/temps and made it work all year. Some of the crappy designs foisted off on the industry by supposedly reputable, old line makers are amazingly loaded with excrement. I even called Lennox and they swore on a stack of bibles that those 2, 1/2 horse motors were enough. I asked what was the expected operating temperature range and he said 75-90F outside. I said and what happens when you have enough heat load to need it, but the outside temp is 33F? Its not designed to run at those temps. Why did you sell it to the State of Nebraska then, you did have the specs, I've seen them? Mumble. Obviously I wasn't talking to a real engineer so I asked him where he got his sheepskin. More mumbling. Being a tv engineer for the state NETV commission, when the nearest help is 200 miles away in Star City, (Lincoln NE) means you truly are a Jack Of All Trades. :) Those 8 years were _very_ educational, but I left because I was still not the lead dog, so the scenery never changed. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Stray Alpha Particles from memory packaging caused Hard Memory Error on Server. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, DJ Delorie wrote: Seconds and not fractions or a second? Yikes! Unless it's a 10-15 ton unit that doesn't sound normal. I think it's a 60 ton. It draws 30 amps once it's running. Yeah, seconds, not fractions. They had to upgrade the transformer on the pole to supply enough juice. Did you find some of the power hogs with your new board by now? Not really. I did discover that the off button on the remote for the receiver in the living room just shuts off the speakers, not the amp, if you used the button on the amp to turn it on. Interesting. My big Kenwood also kills the VF display, but haven't checked the 'off' draw. And I know the tv's all draw at least 20 watts turned off. Is this data obtained from a Kill-a-watt? I measured that all my computer and networking stuff is less than half my bill. Haven't populated the new boards yet, so I can't yet measure the dryer or oven. I have all the stuff I need to populate them, just need some free time (and have to clean my work table ;). Same here. I build additional work area, and its soon buried in work debris. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp River: Also, I can kill you with my brain. --Episode #11, Trash ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, David C. Kerber wrote: Are Kill-a-watt meters any good? I just got one for my company to check loading on UPSs and racks of equipment. Seems ok when I plugged it in and compared its reading to the 5-light load indicator on the UPS. -Original Message- From: geda-user-boun...@moria.seul.org [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Gene Heskett Sent: Wednesday, May 20, 2009 3:12 PM To: gEDA user mailing list Subject: Re: gEDA-user: [OFF] high current amplifier ... Is this data obtained from a Kill-a-watt? D I have heard they are fairly decently accurate as long as the power factor is above 80%. Sadly, many modern electronic loads are below that. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Oh no, not again. - A bowl of petunias on it's way to certain death. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, Joerg wrote: Gene Heskett wrote: On Wednesday 20 May 2009, Joerg wrote: DJ Delorie wrote: Levente Kovacs leventel...@gmail.com writes: 230V times 100A is something I dont want to even calculate. It's 23000 :-) My air conditioner draws 123 amps at 240 volts for the first few seconds. That's almost 30kW. Seconds and not fractions or a second? Yikes! Unless it's a 10-15 ton unit that doesn't sound normal. Did you find some of the power hogs with your new board by now? Off topic reply, but could be germain too. Not even a 40 horse compressor in a 22 ton (rated, yeah sure) Lennox will draw that much for that long. Its startup was a peak in the 250 amps/phase area, and the reason I say area is that a std 400 amp scale on an amp-probe on any phase line swung up to 250 and back down to its running of about 39 amps/phase in a purely ballistic fashion as the startup surge was only 6 or 7 cycles of the 208/3 phase line. Now it really gets off-topic. That was one of those _must_ _work_ units else a tv station was off the air 10 (or less) minutes after it failed. It was also probably responsible for some of the early ozone holes over the antarctic as it was severely under fanned on the condensor side, and I had to add 20 pounds of freon in the fall to keep it working right until it wasn't needed, and bleed that 20 pounds back off as spring turned into summer. This went on for 8 years on my watch, back in the 70's, and long before they started regulating all that stuff. 2 ea. 1100rpm 1/2 horse motors turning 24 fans just didn't cut it. I got tired of that one spring and fixed _some_ of it by taking a failed motor to town, having the brackets stretched to carry 2 horse 1800 rpm motors, replacing the motor with a 2 horse 1800 and repeating it the next week with the second one. 2 horse wasn't quite enough as they ran a couple of amps over nameplate when the condensor was relatively clean. When those blades failed (fatigue cracks, caught before they made shrapnel), I replaced them with blades with an inch less pitch. That allowed it to continue to work until the ambient went over 80 degrees without bleeding freon to keep the high side under 400 psi and the compressor currents under 43 amps/phase else the overcurrents in the compressor would trip. Based on those results, I would have said that a single 20hp motor, running at full load pulling a quad torrington wheel with each half about 16 wide 14 diameter, would have been about right. That could have been throttled with a 4' square louver driven by a M-H proportional control Modutrol to regulate the high side pressures/temps and made it work all year. Some of the crappy designs foisted off on the industry by supposedly reputable, old line makers are amazingly loaded with excrement. I even called Lennox and they swore on a stack of bibles that those 2, 1/2 horse motors were enough. I asked what was the expected operating temperature range and he said 75-90F outside. I said and what happens when you have enough heat load to need it, but the outside temp is 33F? Its not designed to run at those temps. Why did you sell it to the State of Nebraska then, you did have the specs, I've seen them? Mumble. Obviously I wasn't talking to a real engineer so I asked him where he got his sheepskin. More mumbling. Being a tv engineer for the state NETV commission, when the nearest help is 200 miles away in Star City, (Lincoln NE) means you truly are a Jack Of All Trades. :) Those 8 years were _very_ educational, but I left because I was still not the lead dog, so the scenery never changed. :) Thanks for sharing, that was a real story from the trenches. Not looking forward to the 105F days that are coming. I don't need A/C even when it gets to 95F in the office but when visitors come I have to. And then the compressor often goes into bypass mode making that awful rar noise. Then it's waiting 5-10 mins, crossing fingers, make sure no black cat crosses street from right to left, turn switch to the old Lennox back on, hold breath. Then it needs help like I've described. That sort of a locked rotor shutdown is pure hell on the compressors. No other nice way to describe it unforch. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Oh no, not again. - A bowl of petunias on it's way to certain death. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, DJ Delorie wrote: Not even a 40 horse compressor in a 22 ton (rated, yeah sure) Lennox will draw that much for that long. Gee, you guys are making me feel bad. Now I have to go out and research air conditioners :-P Anyway, I know I have a 60 amp circuit for it, and it hits 123 amps long enough for my DVM to stabilize at 123 amps. How long it stays there depends on when it last ran (the first unit broke because it ran too often, and would lock - 123 amps until it overheated and shut down - hence the furnace controller). When it's in a good mood the surge lasts just under a second or so. During hot days it could be longer because it cycles more (minimum 30 minutes off time or it has a hard time restarting). Then put a time delay to off of at least 3 to 5 minutes into the condensor fan circuit only, its killing them both simultainiously, leaving a severe overtemp condition that is falsely holding up the head pressure, or even running it up over 400 psi. There must be enough fan running to liquify the remaining gas, bringing the head pressure down to something the compressor can get restarted against in a timely manner, which should be under 1 second. By the same token, if the evaporator fan in the furnace is being stopped at the same time as the compressor, you have a virtual guarantee that the evaporator will turn into a solid block of ice on a warm muggy day when you will really notice it. It must have enough after-run to vaporize all the refrigerant in the evaporator coils so that they will warm up, thawing any ice that formed when it was running, and running with what may be a borderline low charge, often the case even for new installs. On a long run cycle, long enough to reach steady state conditions, gas charge can be somewhat judged by inspecting the big line where it comes back out of the furnace. It should have a coat of sweat on it, not frost. If no sweat and no frost, (and the air is moving 100% normally) its quite likely down to half charge or less. As you add refrigerant, it will first frost, then eventually clear to sweat, and this is pretty close to the ideal charge level for the conditions that exist that day. Low side pressure/temp should be held not lower than 34F (for whatever gas is in it), and high side pressures/temps to 275F or so maximum. This high side is for older F12 systems of course, I believe that R-134 will run a high side somewhat above that. R-134 is also a much smaller gas molecule and will leak from systems that can hold an F12 charge for decades. That higher high side temps for R-134 also translates to failure of the lube oil that circulates with the refrigerant at a higher rate. This can lead to plugging of the capillary tube used as the expansion restriction in the entry to the A coil in the furnace with flakes of varnish from the overcooked oil too. The tech will generally want to replace the whole coil because of the leak possibilities with even well done silver solder repairs on site. Note that I do *not* have the hard start (aka soft start) kit for this, although I've been thinking about getting it. Those can be very hard on the compressors, prolonging the startup overcurrent phase. Giving it a good stiff supply so it gets started as quickly as possible is actually the easiest on them, far less of an instant overtemp surge. Again I'm referring to multiphase motors of course. Single phase stuff can sometimes be optimized for the starter coil efficiency with a minor change to the quality and size of the starting capacitor. The keyword there is often ESR, and the usual non-polarized electrolytics can be quite poor. Not knowing the phase angle the starter coils are inserted into the stator can make that approach a cuss and cry method though. The 10 kVA transformer wasn't enough for this. At startup, the mains voltage would brown-out to 190 vac. They swapped it for a 25 kVA transformer, and upped my wiring from 00 to coming in to the house. 25kVA, still small. How many houses are they running from it? I think the can on the pole I'm fed from is now a 50kVA, but its feeding 4 or 5 houses. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp If that makes any sense to you, you have a big problem. -- C. Durance, Computer Science 234 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, Levente Kovacs wrote: We want to avoid transformers. The older version of this equippment had the good old Quad-405 power amplifiers, and transformers at the end. It is so heave, that one man can hardly lift the unit. Btw... the same unit must also provide a voltage output up to 300V, but only 100Watts. For that, we'll go for transformer. And a plus... multiply everything by 3, hence it must be 3 phase... :-) Loverly. Next I suppose they like a side of Moose Tracks ice cream to go with their single malt scotch? :) On Wed, 20 May 2009 11:27:48 -0500 Mark Rages markrages-re5jqeeqqe8avxtiumw...@public.gmane.org wrote: On Wed, May 20, 2009 at 11:16 AM, Levente Kovacs leventelist-re5jqeeqqe8avxtiumw...@public.gmane.org wrote: On Wed, 20 May 2009 10:48:53 -0500 Mark Rages markrages-re5jqeeqqe8avxtiumw...@public.gmane.org wrote: What kind of transient are you trying to simulate? Maybe it would be easier to make a circuit to add the transient to mains power, instead of recreating mains power with an amplifier. 230V times 100A is something I dont want to even calculate. -- You need a high-current, low-voltage transformer: http://www.cooperhandtools.com/brands/CF_Files/model_detail.cfm?upc=037103 079480 Regards, Mark markra...@gmail -- Mark Rages, Engineer Midwest Telecine LLC markrages-oYGxGvcBBqUZk/wt9ibm20eocmrvl...@public.gmane.org ___ geda-user mailing list geda-user-3olirty5fqqavzljymc...@public.gmane.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Now KEN and BARBIE are PERMANENTLY ADDICTED to MIND-ALTERING DRUGS ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, der Mouse wrote: A ton of cooling is 12 Kbtu, about the heat of crystallization of one ton of water, per hour. Why do engineers use so many whacky units? [...], tradition and convenience. Good excuses for the masses. Not so good for engineering, which depends on precise communication. Which measuring air conditioning capacities in tons provides. Just because it's disorienting to those who are acquainted with only other meanings of the word doesn't make it any less precise. It's not even ambiguous, since air conditioning capacity doesn't have units of weight. You might as well ask why motor power is measured in horsepower - that's another historical unit that's cryptic and baffling to the uninitiated, but is perfectly good to those in the industry. And the unit called a horsepower is a complete unit also, as I believe its defined as lifting 550 pounds 1 foot in 1 second. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Now KEN and BARBIE are PERMANENTLY ADDICTED to MIND-ALTERING DRUGS ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, Joerg wrote: Gene Heskett wrote: On Wednesday 20 May 2009, Joerg wrote: Gene Heskett wrote: On Wednesday 20 May 2009, Joerg wrote: DJ Delorie wrote: Levente Kovacs leventel...@gmail.com writes: 230V times 100A is something I dont want to even calculate. It's 23000 :-) My air conditioner draws 123 amps at 240 volts for the first few seconds. That's almost 30kW. Seconds and not fractions or a second? Yikes! Unless it's a 10-15 ton unit that doesn't sound normal. Did you find some of the power hogs with your new board by now? Off topic reply, but could be germain too. Not even a 40 horse compressor in a 22 ton (rated, yeah sure) Lennox will draw that much for that long. Its startup was a peak in the 250 amps/phase area, and the reason I say area is that a std 400 amp scale on an amp-probe on any phase line swung up to 250 and back down to its running of about 39 amps/phase in a purely ballistic fashion as the startup surge was only 6 or 7 cycles of the 208/3 phase line. Now it really gets off-topic. That was one of those _must_ _work_ units else a tv station was off the air 10 (or less) minutes after it failed. It was also probably responsible for some of the early ozone holes over the antarctic as it was severely under fanned on the condensor side, and I had to add 20 pounds of freon in the fall to keep it working right until it wasn't needed, and bleed that 20 pounds back off as spring turned into summer. This went on for 8 years on my watch, back in the 70's, and long before they started regulating all that stuff. 2 ea. 1100rpm 1/2 horse motors turning 24 fans just didn't cut it. I got tired of that one spring and fixed _some_ of it by taking a failed motor to town, having the brackets stretched to carry 2 horse 1800 rpm motors, replacing the motor with a 2 horse 1800 and repeating it the next week with the second one. 2 horse wasn't quite enough as they ran a couple of amps over nameplate when the condensor was relatively clean. When those blades failed (fatigue cracks, caught before they made shrapnel), I replaced them with blades with an inch less pitch. That allowed it to continue to work until the ambient went over 80 degrees without bleeding freon to keep the high side under 400 psi and the compressor currents under 43 amps/phase else the overcurrents in the compressor would trip. Based on those results, I would have said that a single 20hp motor, running at full load pulling a quad torrington wheel with each half about 16 wide 14 diameter, would have been about right. That could have been throttled with a 4' square louver driven by a M-H proportional control Modutrol to regulate the high side pressures/temps and made it work all year. Some of the crappy designs foisted off on the industry by supposedly reputable, old line makers are amazingly loaded with excrement. I even called Lennox and they swore on a stack of bibles that those 2, 1/2 horse motors were enough. I asked what was the expected operating temperature range and he said 75-90F outside. I said and what happens when you have enough heat load to need it, but the outside temp is 33F? Its not designed to run at those temps. Why did you sell it to the State of Nebraska then, you did have the specs, I've seen them? Mumble. Obviously I wasn't talking to a real engineer so I asked him where he got his sheepskin. More mumbling. Being a tv engineer for the state NETV commission, when the nearest help is 200 miles away in Star City, (Lincoln NE) means you truly are a Jack Of All Trades. :) Those 8 years were _very_ educational, but I left because I was still not the lead dog, so the scenery never changed. :) Thanks for sharing, that was a real story from the trenches. Not looking forward to the 105F days that are coming. I don't need A/C even when it gets to 95F in the office but when visitors come I have to. And then the compressor often goes into bypass mode making that awful rar noise. Then it's waiting 5-10 mins, crossing fingers, make sure no black cat crosses street from right to left, turn switch to the old Lennox back on, hold breath. Then it needs help like I've described. That sort of a locked rotor shutdown is pure hell on the compressors. No other nice way to describe it unforch. But I can't really bleed off freon. Plus AFAIK they don't sell that stuff to ordinary folk anymore unless you have a contractor's license. I mean, I could get one, but that would go a bit far ;-) Its no better on this side of the pond either, Joerg. I stocked up on the auto stuff 20 years ago when the handwriting was on the wall I may have a 1 pound can in the basement yet that hasn't been tapped. My AC gages have R-134 scales on them, but the hoses can't take the R-134 pressures. I'm not sure, but I think my oldest vehicle (a 99 GMC 3 door, 4wd) now has R-134 in it, and its working poorly, so I'll have to bite
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, DJ Delorie wrote: Then put a time delay to off of at least 3 to 5 minutes into the condensor fan circuit only, I don't have that kind of control over it. I have one low-voltage control loop to tell it on/off, and that's it. It is _your_ AC, right? You have every right to re-engineer the controls that were probably speced by some bean counter who wouldn't know what the high side pressure meant if his life depended on it. I am not the least bit allergic to fixing what is plainly poorly engineered because they perceive that the extra 50 bucks it would take to do it right costs them their competitive edge. Scroooem, that what we do, the _real_ engineering, or we wouldn't be on this list. It may take a while to decipher the drawing inside the outdoor unit to figure out where to add what, but it can be done. By the same token, if the evaporator fan in the furnace is being stopped at the same time as the compressor, It's not, it stays on for a while after that, until the air it's moving warms up. That at least is correct. On a long run cycle, long enough to reach steady state conditions, gas charge can be somewhat judged by inspecting the big line where it comes back out of the furnace. I have a thermocouple in the plenum right after the A/C exchanger, the air in there is nearly freezing. It reads 41F but I think the software is bottoming out because it drops fast and just flat-lines at 41F (that thermocouple system is designed for the woodstove - 0C to 1023C). I'm pretty sure it's OK. I'd want to dbl check with a decent thermometer. Even a $20 dial type for photo darkroom use may be more accurate than the thermocouple in those ranges. But the outlet pipes condition is the better clue IMO. It did have a leak at one point, and we had an A/C specialist come and redo the joints and recharge it, it hasn't degraded since then. Then the after run on the condenser fan should really make a diff. The biggest concern for TD relays, when they are air bleed bellows designs, is that being outside, they don't function well for long term use as they will corrode. There is an electronic TD relay, with a knob on top of the case to adjust the delay, that I have used as replacements for the mercury based TD relays in older Harris transmitters that would appear capable of doing the job, but I don't have the catalog handy as its 1000 miles away in Upstate MI from me. I actually got 3 of them from a local heating/ac place in Iron Mountain MI, IIRC I paid around $50 a copy. Keep those dry and they should work for quite a while. 25kVA, still small. How many houses are they running from it? Just mine :-) I have 7200 VAC coming up the driveway (it's 0.3 miles to the road). Ahh. That explains a lot. I _think_ its 14.4kv on the street here, but don't quote me in court. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp You can't hold a man down without staying down with him. -- Booker T. Washington ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [OFF] high current amplifier
On Wednesday 20 May 2009, DJ Delorie wrote: It is _your_ AC, right? Well yeah, but I don't want to fiddle with it *that* much. Besides, I don't know that they don't already do what you've suggested. IIRC the fan and compressor turn on separately, they might turn off separately too. I've never paid that much attention to them. I'd kill 2 birds then, and grab a lawn chair and a beer, and sit beside it while its running long enough to run out of beer. :) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Time is the most valuable thing a man can spend. -- Theophrastus ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: C++ HDL
On Friday 15 May 2009, Dan McMahill wrote: John Doty wrote: So will the 6L6, but few engineers ever have reason to design with one. However, those who do make oodles of money. Audio freaks seem to have pockets of infinite depths. Sure, but so what? There's no need to train the average EE to do this work. this thread has degenerated a bunch, but I would argue that the average EE *should* be able to design with a 6L6. Actually, maybe something like a 12AX7 (triode) would be better. Why do I say such a crazy thing? Because if a school has done a decent job with its undergrad program than you should be able to go to an engineer with no experience using vacuum tubes, hand him/her the appendix from Gray and Searle that does a basic derivation of a triode operation, hand him/her a datasheet and a schematic and they should be able to right away analyze the circuit and tell you what it is and the basics of its performance. A small signal model is a small signal model. If you've drawn a load line the exact device at hand shouldn't matter. If you understand the idea, the specifics are just that. Details. Minutia that can be relegated to a cheat sheet (brain swap space). That's the difference between a principles based program and an applications/memorization based program. -Dan +10ee34, Dan. That is one of the basic truths I learned long in the past. Its been 65 years since I picked up a hot soldering iron the first time in the early 1940's. I had the principles by the time I quit school at the end of the 8th in '48 and went out to fix these newfangled tv's for a living. Sure, I had to find some algebra and trig along the way, but the principles have _never_ let me down. Too bad many don't grok that. All the vacuum tube stuff has been relegated to the trivia games it seems, or as a sizzle the audiophiles can sell at outragious markups just because IFM. But there are lots of side effects going on inside that vacuum that the younger people will never be exposed to. I guess they work on the IFM principle when they see a 2A3, or a KT-66/KT-88. A 7788? 6336, or a 4-1000? I still deal with most of those, till June 12th anyway since I'm in broadcast engineering. As for the simplification of the triode, that is good for the groundwork but there are all sorts of secondary effects to plug in and account for when you start adding more grid wire shells and beam shaping electrodes. Efficiency and gain can go up, a lot, but it often comes at the expense of some pretty severe non-linearity's once you get out of the sweet spot. So these guys _should_ need a semester on vacuum tubes just to make sure they have the principles, but they need to understand that the principles come with a pretty long 'case:' statement to get them well rounded. Yeah, I think we are offtopic for sure, but that is often where some strong opinions about basic truths can be found. BTW, some of the tube stuff I see now when the garage bands tune up, would quite rightly have been called junk in the 1950's. It is plumb amazing what they will spend a weeks wages on. We sold better stuff for $12.95 back then. Full of microphonics and popcorn noise, and they love it just because 'its the tube sound'. Boggles the mind. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Just pick up the phone and give modem connect sounds. Well you said we should get more lines so we don't have voice lines. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: geda cygwin package
On Friday 15 May 2009, Eric Brombaugh wrote: al davis wrote: On Thursday 14 May 2009, Joerg wrote: What I bemoan is the utter lack of hands-on experience. Most newly minted engineers can't even solder properly. Pathetic. So sad. I recently saw a post on an email list that did a very good job at illustrating, by example, why this is such a problem. You should read it. http://tinyurl.com/p7aze6 A! The deadpan meta-irony makes my head asplode! Eric Yes, there is that. But that comment also demonstrates all too well that old saw about those that can't, teach. Why? Cuz they won't pay someone who _can_ what he can get for that talent in the tech labor marketplace, by about 2-3x. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The problem with graduate students, in general, is that they have to sleep every few days. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: C++ HDL
On Friday 15 May 2009, al davis wrote: On Friday 15 May 2009, Dan McMahill wrote: this thread has degenerated a bunch, but I would argue that the average EE should be able to design with a 6L6. Actually, maybe something like a 12AX7 (triode) would be better. Why do I say such a crazy thing? Because if a school has done a decent job with its undergrad program than you should be able to go to an engineer with no experience using vacuum tubes, hand him/her the appendix from Gray and Searle that does a basic derivation of a triode operation, hand him/her a datasheet and a schematic and they should be able to right away analyze the circuit and tell you what it is and the basics of its performance. A small signal model is a small signal model. If you've drawn a load line the exact device at hand shouldn't matter. If you understand the idea, the specifics are just that. Details. Minutia that can be relegated to a cheat sheet (brain swap space). That's the difference between a principles based program and an applications/memorization based program. My students would be able to design with a 6L6, if they could design with anything. I would not be afraid to include a tube circuit on the final exam of an upper level electronics course, even if they had never seen a tube before. It's just a device, with certain characteristics. Maybe I would give them some curves, Maybe the equation of plate current vs grid voltage. I would not use a 6L6 for this. I would use a tube that is still in mainstream use today, maybe make up one. How about a 3CX2. (A ceramic triode rated at 2 watts.) Where would you use something like this? 50 kw radio transmitter. I always tried to include something on every test that would catch the memorizers off guard. I did explicitly cover tube circuit design in a communications systems course. .. complete with examples showing reasonable voltages and currents ... 12000 volts, 4 amps ... Al, your students may have sworn at you then, but I hope 10 years down the log, that they mention you in their nightly prayers. You are a GOOD teacher. To really get off topic: Did you cover amplifier klystrons? A 4KM100LA runs on about 20kv, and nearly 6 amps, and needs a minimum of 55 gallons of water a minute to cool the collector bucket. Out of style now because the diacrode is 3x more efficient, an important item to the bean counters when your transmitter is the local power companies biggest customer. Tuning one of those is almost magic, one miss-adjustment for about 10 milliseconds and you have $150,000 worth of junk. At one time there may have been 100 guys alive who could do that, including me. Now its a footnote in history, and we are slowly dying off. But, damned if we haven't had fun! -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The pyramid is opening! Which one? The one with the ever-widening hole in it! -- The Firesign Theatre ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: FT232R
On Wednesday 08 April 2009, Mike Hansen wrote: Quick FYI: The FTDI USB UARTs have noise immunity issues. They tend to lock up after running for an hour or so. And worst of all they only reset themselves when the USB cable has been physically removed. It's a well known problem. I would avoid this chip for new designs. I could almost argue the point about FTDI stuff. I'm also on the heyu list, where a couple of years ago we became aware that 99% of the adapter problems heyu was having (and coincidentally the apcupsd list found the same) were related to the user using a PL2303 based adapter. So we started telling the newbies to bin them and get FTDI stuff, because it Just Works(TM). And it does, there are 5 or 6 of them in this system right now, and they are dependable and 100% transparent. 2 of the ones I am using are booster hubs on the other end of 16 foot cables. Nary a hiccup in a years use. Mother nature blew one of them all to hell, but when the systems are 25 feet apart, the EMP from a nearby strike can do heavy duty things to electronics. Suggest looking at something from SiLabs. Date: Wed, 8 Apr 2009 17:32:08 -0400 From: d...@delorie.com To: geda-user@moria.seul.org CC: mrumun...@popdial.com Subject: Re: gEDA-user: FT232R Ah, the perils of open source. With proprietary software, your problem is not enough symbols. With open source, your problem is too many. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user _ Rediscover Hotmail®: Get quick friend updates right in your inbox. http://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Upd ates1_042009 -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) It is not good for a man to be without knowledge, and he who makes haste with his feet misses his way. -- Proverbs 19:2 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Putting holes in hard steel - was - Re: the joy and sadness of new boards
On Friday 03 April 2009, evan foss wrote: On Fri, Apr 3, 2009 at 8:24 PM, Gene Heskett gene.hesk...@verizon.net wrote: On Friday 03 April 2009, evan foss wrote: On Fri, Apr 3, 2009 at 6:36 PM, andrewm andr...@thehacktory.com wrote: If anybody has a better idea, yelp. EDM ? Don't you aready need a hole to run the wire threw? A hole for a wire through it? No. Or are you just going to live with a very thin line cut threw to the hole? If your are going to spend EDM level money water jet would be better. Drilling holes with EDM? Straight plunge cut/burn. Hole size determined by the electrode in this case. Only milling machine motion if I get the right electrode size is z, at about .001 a minute, which emc can manage nicely. I have everything but the right sized electrode on hand. Even some trash that needs burnt by tossing the used kerosene on it. :) Oh yea I was just thinking about wire edm not sink edm. Sorry. Hey, stuff happens. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) It seems a little silly now, but this country was founded as a protest against taxation. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Who loves not wisely but too well Will look on Helen's face in hell, But he whose love is thin and wise Will view John Knox in Paradise. -- Dorothy Parker ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: the joy and sadness of new boards
On Wednesday 01 April 2009, Ethan Swint wrote: Gene Heskett wrote: On Tuesday 31 March 2009, DJ Delorie wrote: Hey, they have a 4.5 diamond blade that will fit in my table saw, too. They don't say how wide it is, though.I think those are meant for sawing concrete or ceramic tiles, so they are a good fat 3/32 wide, and the ones I have wobble that to an eighth inch at least. The diamond blade that I have is also about that thick, but it doesn't wobble - you might have a problem with your arbor. A cheap tile saw (~$65 at a hardware store) wouldn't be a bad idea - the water keeps down the dust - just so long as you have sufficient intra-panel clearance for the saw's kerf. I made the arbor, seating face against which the blade rests, and the 1/2 shank were all done on a small lathe without touching the chuck jaws. I've a small dial indicator that has about .001 resolution, and it saw no wiggle, none. Ell Cheapo chinese blades, I only have about 5 bucks each in a pair of them. I intended to use them to sharpen carbide bits, but the diamonds were so coarse they actually chipped the carbide. I was looking for edge linear speed since my spindle is only 2500 revs wide open. So now I use that new quick change dremel arbor in a 1/8 collet, with about a 1.75 diameter diamond saw in it, that works fairly well, just slow when using a don't wake the child kiss touch. Sorta off topic: I have a rotary table for the A axis too, and was going to see if I could freshen the edges of some of my saw blades from the woodshop, but the first 10 Hitachi thin kerf blade I laid on the jig to drill holes in near the hub so I could bolt it to the t-slots of the tables face educated me quickly. 4, 1/4 decent quality drill bits later, I have dimples about 3/32 diameter in the blade. Its going to take a carbide bit to drill that chrome plated Hitachi steel! If anybody has a better idea, yelp. They have to be draw blood sharp if you are going to get clean cuts without burning in cherry. So far, only Hitachi and Avanti blades are that sharp still in the blisterpack at Lowes. Bring money of course, a 60 tooth 12 blade for the chop saw is about $70. 10 40 tooth for the table saw is about $40. -Ethan ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Kaufman's Law: A policy is a restrictive document to prevent a recurrence of a single incident, in which that incident is never mentioned. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Putting holes in hard steel - was - Re: the joy and sadness of new boards
On Friday 03 April 2009, andrewm wrote: If anybody has a better idea, yelp. EDM ? Humm, hadn't thought of that, but I did that a couple of years ago, removing some broken 6-32 taps from some blind holes about 3/4 deep. This was while building a new z axis drive for my micromill. PIMA to do, but it worked just fine if my time was only worth a nickle an hour, but when you are retired its sorta hard to place a value on time since nobody is paying me. And I've since acquired some much healthier transformers and rectifiers, so it shouldn't take 2 days per hole either. They change my ability from .35 amps at 28 volts to about 5 amps at 65 volts, but my resistors 50 ohms, 400 watt, will limit that to a bit over an amp under short circuit. Should make more better smoke that way. :) Thanks for reminding me of that. In this case, how about I get some of that brass tubing that's a bit over 7mm from the hobby shop and use that for electrode. No use removing the plug in the middle .01 at a time. :) Maybe I could even drill a porthole in it, and run it through a tee with o- rings to seal, and have a continuous kerosene flush, which would speed it up even more. I also found it seemed to help if the spindle was turning the electrode about 50 rpm to stir the dielectric. Yeah, come some warmer weather I'll do just that. Too cold for a diabetic with poor feet circulation to fiddle with now. That shop building has very little heat, just enough to keep it above the dew point _most_ of the time. Thanks! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The road to ruin is always in good repair, and the travellers pay the expense of it. -- Josh Billings ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Putting holes in hard steel - was - Re: the joy and sadness of new boards
On Friday 03 April 2009, evan foss wrote: On Fri, Apr 3, 2009 at 6:36 PM, andrewm andr...@thehacktory.com wrote: If anybody has a better idea, yelp. EDM ? Don't you aready need a hole to run the wire threw? A hole for a wire through it? No. Or are you just going to live with a very thin line cut threw to the hole? If your are going to spend EDM level money water jet would be better. Drilling holes with EDM? Straight plunge cut/burn. Hole size determined by the electrode in this case. Only milling machine motion if I get the right electrode size is z, at about .001 a minute, which emc can manage nicely. I have everything but the right sized electrode on hand. Even some trash that needs burnt by tossing the used kerosene on it. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) It seems a little silly now, but this country was founded as a protest against taxation. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: the joy and sadness of new boards
On Tuesday 31 March 2009, DJ Delorie wrote: Do you know anyone with a sheet metal shear? I had my eye on either the small 8 HF shear or a slightly larger 12 Grizzly one. I have a friend who is a metalworker, too, and yes, I was planning on asking him if he had one. By panel I meant 6x10, not the 14x14 panels the fab uses. If you are intent on sawing, how about a Dremel cutoff disk? I'd rather not - that's a lot of cutting for a somewhat fragile disk. Dremel now has a 1.5 or slightly bigger diamond wheel that fits the quick change arbor. Its a bit pricy at about a 20 dollar bill, but its the closest I've come to a do anything wheel yet. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Do not read this fortune under penalty of law. Violators will be prosecuted. (Penal Code sec. 2.3.2 (II.a.)) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Stuart's gEDA Talk at Ignite 5 Boston
On Thursday 26 February 2009, John Luciani wrote: The video of Stuarts gEDA talk is at http://ignite.oreilly.com/news.html (* jcl *) Unforch with a quad core phenom and 4GB of memory, plus mplayer-3.55, it plays at about 2% of normal speed, with no discernable cpu or drive activity even after giving it time to all be received over my adsl circuit. .mov's generally play well here. Video card is a Diamond HD2400-Pro, rv610 chipset, currently booted to the last fedora 8 kernel using some sort of a fedora neutered fglxr driver. But, in trying to do something with the radeonhd driver, I broke x and had to upgrade to Fedora 10 to recover. So x is no longer broken but is so slow I need to call a surveyor to measure progress in moving a window etc. Inches per fortnight I believe is the correct measurement scale. Sheesh. Wish I could watch it though. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) It's pretty hard to tell what does bring happiness; poverty and wealth have both failed. -- Kim Hubbard ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: duplique
On Wednesday 21 January 2009, Patrick Dupre wrote: Hello, After I made a pcb, can I duplicate it on the same silk ? Then I go get several at the same time. Thank If you mean making another pcb by using the same silk, yes. We used to do that 40 some years ago at a tv station, where such things as audio and video DA's are often used by the dozens. But because the silk will dry and clog up if you don't very carefully rinse all the ink out of it, You should do as many as you need plus another 25% or so for future expansion use when the silk is ready to use. When we cleaned the silk up, it was total, and then ready to re-use for the next board we made. The same silk frame will last for several years worth of small production runs if cared for. Today though, with the narrower traces commonly used, I'd suspect the hand work to fix holes and smears would probably soon drive you to a photographic resist process. Or to cutting machinery, needing no etch chemistry at all, just a good board scrubbing when its done from the plating of thru holes and via's. That plating was the one process we didn't have the stuff to do, but our spray etcher could preserve our notes written in the 10x10 when reduced 4/1, perfectly readable at .025 high in the copper, which amazed me in the middle 60's when I was doing it. Seems like silk screen for pcb's would be rather arcane technology today though. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Message from Our Sponsor on ttyTV at 13:58 ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Power (and other non-graphical) pins
On Friday 16 January 2009, Steven Michalske wrote: it's called the knack. http://www.youtube.com/watch?v=CmYDgncMhXw :-) Chuckle, I was wondering when somebody would make a video out of that classic. Thanks for the link, bookmarked for future use. :) On Jan 15, 2009, at 8:50 PM, Steve Meier wrote: or in DJ's case I think he just can't help but be creative ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The sooner you fall behind, the more time you have to catch up. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: electrolytic capacitors
On Monday 29 December 2008, Bill Gatliff wrote: KURT PETERS wrote: Just curious, I wonder what's inside the blue one? :-) Turtles. All the way down. :) ROTFLMAO! b.g. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) A banker is a fellow who lends you his umbrella when the sun is shining and wants it back the minute it begins to rain. -- Mark Twain ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: electrolytic capacitors
On Sunday 28 December 2008, der Mouse wrote: [Electrolytics] can explode pretty violently, so let me tell you a story. [...785V on a 450V cap...serious dent in plaster...] My exploding cap story is not quite so impressive, but I know I certainly found it convincing. I put together a circuit - can't even remember what it was, now - on one of those solderless breadboards. Turned it on and it seemed to be working, but then I heard this hissing noise. I was just starting to try to locate it when the cap let go. Fortunately it was a small one (perhaps half a millicoulomb rating); all it did was make a bang and a small cloud, which settled in moments to cover everything within about a 6 radius with a thin film of something oily-feeling. Ethylene Glycol, very very pure antifreeze. On reflection, I realized I'd been running it at something like twice its rated voltage. That will generally do it every time. :) Ever since I've been substantially more careful to think about voltage ratings when selecting electrolytics. /~\ The ASCIIMouse \ / Ribbon Campaign X Against HTML mo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The cart has no place where a fifth wheel could be used. -- Herbert von Fritzlar ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: electrolytic capacitors
On Saturday 27 December 2008, Robas, Teodor wrote: Do not count on this kind of capacitors: http://deep-blue.ro/tmp/chinese%20capacitor.jpg :)) What a ripoff. No way in hell that would last more than a day, if that long with 50 volts of bias on it, (I'd guess 10 minutes max) and I'd have doubts even the dual can would contain the debris. I take it you got curious when incoming QC said they weren't in spec? BTW, that is a neat opening of the can you did. They can explode pretty violently, so let me tell you a story. Back in the mid-60's I came across a tube type, mobile cb radio that had to be one of the few attempts to build one for a 6 volt vehicle system, and predated the old Johnson whiteface by probably 10 years. My pickup at the time, a 52 ford, had long since been converted to 12 volts, and I was in the radio, on the kitchen table, moving wires to convert it to 12 volts. I missed one without realizing it, and had it running on a 12 volt supply for test. It worked really really well, talking to the neighbors on a piece of wire laying on the floor for an antenna. But after about 15 minutes the main filter capacitor let go, and the top of the can put a quarter sized print in the plastered ceiling that was about 1/4 deep. I'm glad I wasn't in front of it at the time, else I might have been seriously injured. I tried with a 20 oz hammer and could not put a dent that deep in that plaster with it. Putting my meter on the stubs of the cans terminals I found the supply was making a hair over 785 volts, and the can carried a 450 volt label. I cleaned up the mess, replaced the cap, and found the other 2 taps on the transformer that I had missed, and ran that radio till I finally got a transistorized one. But my kids, who were upstairs in bed at the time, have always said, somewhat tongue in cheek, that daddy was shooting at them. :) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The best diplomat I know is a fully activated phaser bank. -- Scotty ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: electrolytic capacitors
On Saturday 27 December 2008, Dan McMahill wrote: Gene Heskett wrote: They can explode pretty violently, so let me tell you a story. Back in the mid-60's I came across a tube type, mobile cb radio that had to be one of the few attempts to build one for a 6 volt vehicle system, and predated the old Johnson whiteface by probably 10 years. My pickup at the time, a 52 ford, had long since been converted to 12 volts, and I was in the radio, on the kitchen table, moving wires to convert it to 12 volts. I missed one without realizing it, and had it running on a 12 volt supply for test. It worked really really well, talking to the neighbors on a piece of wire laying on the floor for an antenna. But after about 15 minutes the main filter capacitor let go, and the top of the can put a quarter sized print in the plastered ceiling that was about 1/4 deep. I'm glad I wasn't in front of it at the too funny. My exploding cap story is also related to automotive electronics. The explosion happened at 2 AM when I was in high school. Mom and Dad were not too thrilled about it if I recall correctly. Makes a lasting impression though doesn't it? Yup, one I sure won't forget this side of the rapture. It left my ears ringing slightly, but they've done that since back in the mid 60's when I wore out the first 2 barrels on Old Meat in the Pot, shooting on my own property with 2 good sized trees less than 10 feet away from the front of the bench, without earmuffs. The back blast off those trees was substantial. :( Now at 74, I've been considering a hearing aid, but can't seem to get my hand to write a check for a decent used car that fits in my ear. -Dan ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Certainly there are things in life that money can't buy, But it's very funny -- did you ever try buying them without money? -- Ogden Nash ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: electrolytic capacitors
On Friday 26 December 2008, Peter Clifton wrote: On Fri, 2008-12-26 at 21:00 -0500, gene wrote: What does it mean when manufactures specify 'Endurance @ temp' or 'life time @ temp'? For example, one company claims: Endurance : 105 C 1000 h to 5000h Then they further state that after testing at 105C with maximum ripple current applied, that when the part is cooled to 20C, it will then meet original specs. It will still have had its life-time shortened. The spec you quote above, AIUI, means that after somewhere between 1000 and 5000 hours of operation at 105 degrees centigrade, the cap (as measured at 20 degrees) will be outside of its quoted specifications. I can't remember the exact numbers, but derating to lower temperatures has a stupid factor of lifetime increase. It might even be as much as double the life-time for every 10 degrees drop in working temperature. I guess that merely being at elevated temperature is also lifetime degrading. You circuit wouldn't need to be on for the electrolyte to be degrading. As long as the seals hold, the electrolyte won't degrade. Its not the electrolyte that causes most caps to go out of tolerance. The most often seen failure in recent years has not been that of reduced capacity, but sky high ESR. I have seen caps marked 220 uf at 10 volts read 240 uf on a std cap tester, but toss a capacitor wizard at them, which tests them with little or no bias, measuring instead their series resistance using a 100khz low level signal, and they will be 5+ ohms at 100khz. Digital circuits go crazy when their supply rails are being bypassed with such a capacitor. What happens when you have such a capacitor in a switching power supply? Easy, those things can put 10 or more amps of ripple currents through such a capacitor, and 5 ohms with 10 amps rms flowing through it equals an explosion as that is 50 watts of power being dissipated in a little can the size of half a joint of your little finger. But it normally doesn't come to that, the voltage surges they allow as the ESR rises above the 2 ohm range usually blow one or more of the switching transistors, followed 50ms later by the line fuse. The culprit of course is the connection between the terminals on the bottom of the can, and the microscopicly thin alu foil the capacitor is made of. A truly 'gas tight' joint simply cannot be done when the foils are so thin you can literally see through them. For best life, keep the caps as cool as you can, and if the capacitance is to be maintained over an extended time period, then the applied bias should be at least 80% of the nameplate rating. Reduced below that, the alu will chemically 'deform', meaning the acid like etching that creates the dielectric film at 10 to 50 times the measured square inches, will eventually smooth enough to cause a loss of the dielectric area, and hence a loss of capacity. The real plates of an electrolytic capacitor are not the two separated alu foils, but the alu oxide coating of the etched foil. The glycol essentially is there for the ride (it has a high dielectric constant and isn't really a great insulator) and its etch restoring properties under sufficient bias. If any of you do service work involving such parts, one of the first things to look for is an alu can with a bulged top (replace it, then measure to confirm :), which tells you the ESR is high and that cap is running hot enough to boil the glycol, possibly blowing the seal in the bottom, but occasionally will split the top open on the scores in the alu can put there for exactly that purpose. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Q: What do you call 50 Microsoft products at the bottom of the ocean? A: A darned good start. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: oval holes?
On Saturday 20 December 2008, DJ Delorie wrote: If it were me, I'd just use round holes with sizes calculated from the tab sizes. It might be a bit of guesswork, though, as they don't list the tab thickness on the spec sheet. But that's because I don't have a drill that makes rectangular holes. Back in the '60's, we used to have mechanical drawings on how to make stuff like that, square holes, offset half the diameter etc stuff. IIRC the engineers at Martin Marietta published those. But I never actually saw on of those drill bits. I read the whole thing (about 10 pages of very detailed drawings not even James Randi could make) and was forced to use a goodly quanity of salt to get it all down. :) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Most general statements are false, including this one. -- Alexander Dumas ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: stupid lead-free
On Sunday 27 July 2008, gene wrote: have you guys seen the 'tin-whisker' problem with lead free solder? Yes, heck I've seen it with leaded solder. The alloy RCA used to mount their tv set PCB's to the chassis frames both fractured rapidly, and did that in as little as 6 months to 5 years. Poking at electronics for a living for nearly 60 of my 73 years, I guess that does date me a bit. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Happiness is a hard disk. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: stupid lead-free
On Sunday 27 July 2008, Bob Paddock wrote: On Sunday 27 July 2008 07:49:10 am gene wrote: have you guys seen the 'tin-whisker' problem with lead free solder? Note that these links are from 2006, but still give an interesting background. http://www.greensupplyline.com/showArticle.jhtml?articleID=181401276 http://www.indium.com/blogs/Dr-Lasky-Blog/entry.php?id=444 has some interesting things to say about this issue. Like SWatch's billion dollar recall. Designing ultrahigh impedance circuits like Electrostatic meters, or ultra low power circuits have always been problematic. Lead Free isn't doing anything to make things easier. What I find most annoying is the comment in the above blog that he considers five years long term. See a previous rant of mine on this issue: http://www.dragonsgate.net/pipermail/icc-avr/2002-October/000347.html RANT ON I want my products to have a life of 10 to 20 *YEARS*, not 6 months. I do my designing in the region of the country affectionately called The Rust Belt by the Semiconductor people. We do the unglamorous things like water and sewage treatment controls for example. The infrastructures can't afford to upgrade every few months just because some one wants to play PacMan on their Cell Phone. Consider this: Which is more important to you: A) You can play PacMan on your Cell Phone. B) When you flush it goes away and you don't have to think about it. RANT OFF Excellent rant. S/B forced reading for the regulators. [Can anyone explain this grammatical anomaly that the spelling checkers says ultrahigh is a correctly spelled word, but ultralow is not?] Dunno, mine seems to have stopped working recently. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) You can fool all the people all of the time if the advertising is right and the budget is big enough. -- Joseph E. Levine ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Converting RS274D to RS274X
On Sunday 13 April 2008, Jesse Gordon wrote: Gene Heskett wrote: On Sunday 13 April 2008, Jesse Gordon wrote: A list lurker, speaking up as I run EMC2 on a tabletop mill here. This seems like a neat idea Jesse, but can gerbv show 3D? RS-274-D, from NIST, as interpreted by late versions of EMC2, can describe 9 different axis's gerbv would seem to be at most a 2D display, possibly with tightly spaced overlays that can be laid on or peeled off. I'm currently setup to do 4 axis's, with the 4th being a rotate the work surface using the X axis as the axle to turn on, although I can lay the rotary table down and use it to present the end of the workpiece to the cutter tool too. I'd be interested in seeing such a 3+D display, although my well aged mind cannot well grasp how it might be done, let alone suggest how to do it. Wow, I didn't know about multiple dimensions on RS275D. We here in the PCB world pretty much just use it as a 2d photoplotter format. -Jesse :) Yes, but a utility to extract, and make gcode out of the copper pattern removal, would be a very useful utility. Even if we have to edit the output to insert the scale factors and other housekeeping functions a gcode file should contain, we would be a long way down the road to automating the process. For my own machine, an HF Micromill, it would be slow indeed as my max spindle speed is 2500 rpm. Depth of cut control when changing tools is also a major problem because tool projection depends on how tightly the collet is pulled. This, for pcb carving work, would demand we take it someplace where the tool can be measured by setting it down on a homing switch and rezeroing the Z axis before continuing. But the outline cutting, done with a 10 mill bit or smaller, would be code very similar to running the copper pattern through potrace. I have seen boards where the copper wasn't disturbed except for the removal of the outline, which of course leaves large areas of copper that isn't connected to anything, and which may not be what the circuit needs because of stray capacitance. There are no doubt other considerations, but they are only more lines in the software. And this way is chemistry free. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) ...if the church put in half the time on covetousness that it does on lust, this would be a better world. - Garrison Keillor, Lake Wobegon Days ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Converting RS274D to RS274X
On Monday 14 April 2008, Jesse Gordon wrote: Gene Heskett wrote: On Sunday 13 April 2008, Jesse Gordon wrote: :) Yes, but a utility to extract, and make gcode out of the copper : pattern removal, would be a very useful utility. I thought about that, but it's far above my math skills. -Jesse I don't think there is a lot of what we would call 'fancy math' required. Basically, you look at a line of copper, find the outside edge, add the radius of the cutter, and follow this line, checking that its diameter is not too big and would cut away something on the backside as it moves write a gcode line to trace from here to there. Corners and corner radius would be the major 'artistic' problems. Except for the transcendentals needed for curves, and they can be approximated by very short straight lines, it would be almost 100% add subtract. And possibly conversion into the base unit of emc, which is inches to about 5 or 6 places right of the decimal, or mm with about 4 or 5 places right of the decimal. More accurate than the machinery generally speaking, but that would depend on the machine of course. However, I just took my mouse apart to re-solder the left mouse button as it was giving me double and triple hits per click, a classic symptom of a broken solder joint on the bottom of the board because the switch was not held firmly against the board when it was originally soldered in, and I take it back, that pcb could not be done with a 10 mill bit, 2? Maybe. So we're gonna get plumb picky about cutter sizes with the expectation of paying quite a bit more for those sizes in carbide. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) In 1880 the French captured Detroit but gave it back ... they couldn't get parts. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Converting RS274D to RS274X
On Sunday 13 April 2008, Jesse Gordon wrote: Ormund, If all else fails, and if you can find two documents describing in simple terms each of the formats, I'd be willing to try making a perl script to convert for you. But I'm pretty busy, so make sure there's not already such free solution :-) Also I would need a source RS274D to test with. I'm assuming that once my converter is working, I'd be able to view the result in gerbv. -Jesse A list lurker, speaking up as I run EMC2 on a tabletop mill here. This seems like a neat idea Jesse, but can gerbv show 3D? RS-274-D, from NIST, as interpreted by late versions of EMC2, can describe 9 different axis's gerbv would seem to be at most a 2D display, possibly with tightly spaced overlays that can be laid on or peeled off. I'm currently setup to do 4 axis's, with the 4th being a rotate the work surface using the X axis as the axle to turn on, although I can lay the rotary table down and use it to present the end of the workpiece to the cutter tool too. I'd be interested in seeing such a 3+D display, although my well aged mind cannot well grasp how it might be done, let alone suggest how to do it. Ormund Williams wrote: Hi All Dose anyone know of a utility to convert RS274D to RS274X? I have a few gerber files I want to view but they are in D format with the aperture list in a human readable format. I converted one manually a few years ago now I wish I had taken the time to write a program then. Regards __ Ormund ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Budget cuts ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Converting RS274D to RS274X
On Sunday 13 April 2008, Ormund Williams wrote: On Sun, 2008-04-13 at 13:54 -0400, Gene Heskett wrote: A list lurker, speaking up as I run EMC2 on a tabletop mill here. This seems like a neat idea Jesse, but can gerbv show 3D? RS-274-D, from NIST, as interpreted by late versions of EMC2, can describe 9 different axis's gerbv would seem to be at most a 2D display, possibly with tightly spaced overlays that can be laid on or peeled off. Hi Gene The Gerber format was a subset of the real RS-274D standard and I've never seen any Z axis data in a gerber file. gerbv can't show 3D images. And in my case there is not only Z, but A too. I'm currently setup to do 4 axis's, with the 4th being a rotate the work surface using the X axis as the axle to turn on, although I can lay the rotary table down and use it to present the end of the workpiece to the cutter tool too. I'd be interested in seeing such a 3+D display, although my well aged mind cannot well grasp how it might be done, let alone suggest how to do it. That well aged mind has contributed much to my meager wisdom as I try to design a circuit assembly robot, see you on the EMC list. Thanks for the flowers, Ormund, I appreciate them. Regards __ Ormund ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Windows found - Remove? (Y)es (S)ure (F)ine (O)K ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Converting RS274D to RS274X
On Sunday 13 April 2008, Gene Heskett wrote: On Sunday 13 April 2008, Ormund Williams wrote: On Sun, 2008-04-13 at 13:54 -0400, Gene Heskett wrote: A list lurker, speaking up as I run EMC2 on a tabletop mill here. This seems like a neat idea Jesse, but can gerbv show 3D? RS-274-D, from NIST, as interpreted by late versions of EMC2, can describe 9 different axis's gerbv would seem to be at most a 2D display, possibly with tightly spaced overlays that can be laid on or peeled off. Hi Gene The Gerber format was a subset of the real RS-274D standard and I've never seen any Z axis data in a gerber file. gerbv can't show 3D images. And in my case there is not only Z, but A too. I'm currently setup to do 4 axis's, with the 4th being a rotate the work surface using the X axis as the axle to turn on, although I can lay the rotary table down and use it to present the end of the workpiece to the cutter tool too. I'd be interested in seeing such a 3+D display, although my well aged mind cannot well grasp how it might be done, let alone suggest how to do it. That well aged mind has contributed much to my meager wisdom as I try to design a circuit assembly robot, see you on the EMC list. Thanks for the flowers, Ormund, I appreciate them. Where the effort of doing a conversion would be more appreciated, at least from my side of the fence is in something that could convert the copper patterns gEDA can make, directly into an RS-274-D format, making it simple to lay out a double sided board, and do it on the mill by removing the unwanted copper. Humm, ISTR a was utility called hpgl that I used to run on an amiga, which could filter the output of the amiga pcb design proggy whose name I've long since forgotten and drive a printer to make the exposure mask on transparency film. From that, it seems to me we ought to be able to take the guts of Peters POTrace and generate the gcode for a given layer and carve it. Has anyone done any work long those lines? I keep getting sidetracked with the real world of late it seems. Malfunctioning tv transmitters and such. Regards __ Ormund ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) I think my career is ruined! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Strange (laser) print defects
On Tuesday 18 March 2008, John Coppens wrote: Hi all. Though this evidently is not a software defect, I'm wondering if someone on the list knows the cause of this problem or experienced similar effects. I was testing another paper (touted by a local electronics magazine as 'ideal') for my quick-and-dirty toner-transfer PCBs, and found a strange defect, hard to describe. (see: http://jcoppens.com/misc/laser1.jpg and http://jcoppens.com/misc/laser2.jpg ) The right part of each pic is normal typewriter paper, the left one is on the new paper I'm testing. The faults are systematic: - The appear always on the same spot in the board, independent from where I print it on the sheet. - They never appear on the 'normal' paper. - Printer settings and source file is exactly the same, of course. (I did experiment with different settings, but no difference was noted on the printout). First feeling was that some particle on the paper surface 'exploded', and blew away the toner before it got fixated. But this shouldn't happen systematically on the same spot. Problems with the paper/toner transport? They should show on both printouts, shouldn't they? One would certainly think so John. You may be onto something with the before its fixated idea though, This is a laser, and the heat to fuse (fixate the image) might be related to it. What I think I would do is waste a couple sheets, but make the first run with the printer set at half density, the next one at 25% etc to see if it goes away. I'm thinking there might be a liquid buildup there that would spatter away as the heat was applied to this much less porous medium, particularly if the heating effect at that point was coming in at an angle. The transfer images appear to have plenty of toner, and reducing it via the density setting might at least prove the theory. It appears to have density to spare in your scans. If that has no effect, then I'm afraid I don't have any better clues other than to try another, different transfer medium. Ideas? John ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) sushi, n.: When that-which-may-still-be-alive is put on top of rice and strapped on with electrical tape. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Strange (laser) print defects
On Tuesday 18 March 2008, Samuel A. Falvo II wrote: On Tue, Mar 18, 2008 at 9:14 AM, John Coppens [EMAIL PROTECTED] wrote: I was testing another paper (touted by a local electronics magazine as 'ideal') for my quick-and-dirty toner-transfer PCBs, and found a strange defect, hard to describe. (see: http://jcoppens.com/misc/laser1.jpg and http://jcoppens.com/misc/laser2.jpg ) Permission denied (403) errors when attempting to view the pictures. Thats odd, FF3b4 loaded them almost instantly here. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) management, n.: The art of getting other people to do all the work. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Strange (laser) print defects
On Tuesday 18 March 2008, John Coppens wrote: On Tue, 18 Mar 2008 14:09:30 -0400 Gene Heskett [EMAIL PROTECTED] wrote: I'm thinking there might be a liquid buildup there that would spatter away as the heat was applied to this much less porous medium, particularly if the heating effect at that point was coming in at an angle. Neither the paper nor the toner contain any liquid, so that ouldn't be the source (If the paper were the source of the problem, it wouldn't repeat on the same spot. There is something in the toner that while not liquid, is certainly thermalplastic, and that generally involves something that could be volatile, maybe even explosive at high temps. Toner recipes of course are guarded by armed guards and pit bulls 24/7 as that is the 'magic twanger' that makes it all work. Most printer folks would have no problem killing those who would try to obtain that very proprietary info without being part of the crew that actually mixes it. It is all a very cloak and dagger business. The problem _is_ pre-fixating, as those mini-clouds are fixated. I'm somewhat miffed at the problem - my quick 'n dirty process is failing badly here (at least the quick part). Sounds like! Anyway, the density change is a good idea, and I'll try to get some more sheet tomorrow. Thanks! Let me know if my thoughts were worth the electrons to send them :) John ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Real Programs don't use shared text. Otherwise, how can they use functions for scratch space after they are finished calling them? ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Any TV repair gurus lurking?
On Saturday 22 December 2007, Darryl Gibson wrote: Dan McMahill wrote: By far the worst shock I've ever received was 23 years ago working on a Fender Bassman that was unplugged. I will *never* forget to discharge caps again. Especially ones charged up to 500 volts. Thats one of those mistakes you won't make twice. Yep, that's a bad day, but you lived to talk about it, and pass on the warning. My worst shock came when I was working on a plasma etching machine. Had to stick my head inside to take some voltage readings, found the voltage, with my pinky finger, rather than the meter probe. That was bad, but,,, trying to get away from that, I hit my head on the 440vac contactor which was over my head. That HURT, and I was wearing a hat! Told my boss he had choice, I was going outside and having a smoke, and he could have the design engineer work on the problem, or, I was going to find the blankety blank engineer, and pound him into the floor. The engineer showed up, and after we got things working, he decided it wasn't a good idea to put the 440 contactor on the roof of the cabinet, and he moved it to one of the side walls. I'm partly at fault here, I was taught in tech. school that usually the shock won't hurt you, but getting away from it will. To prove the point, the teacher made the lecture while holding a live suicide cord. Suicide cord? Not fam with that item. However, do not ignore the trauma of the shock, it can come to haunt you very very painfully in the ensuing time frame of 6 months or more. If you've ever had the chicken pox, aka herpes zoroaster, and is there one here who didn't have it as a child?, that virus lives dormant in your major nerve sheathing the rest of your life. The trauma of the shock can awaken it for another round, only this time its called 'shingles'. It will redefine your personal pain tolerance level, upwards. I managed to get across the tickler transformers in the HV cubicle of a GE TF-3a amplifier (part of a tv transmitter, that's my game) and got 2nd degree burns on both arms and my chest area before I got kicked loose. I was looking for a cotter key washer for one of the HV shorting assemblies that I had dropped as I was getting tired after about 16 hours non-stop of fixing up a snake explosion fire. I was instantly so tired I had to go take a nap for several hours, and eventually had my heart checked out but it was fine and still is. But 3 days later I had shingles breaking out all along the major path that about 260 volt 3 phase ac took through me. The pain was disabling and I missed about 3 weeks worth of work. Twas not fun by any sane definition, and to this day, 15 years later, my lower chest and diaphram area have never been completely pain free. I still find it amazing how old timers can predict the future. That is often because we've been there, done that, even bought the T-shirt describing our carelessness. :) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) A small town that cannot support one lawyer can always support two. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Any TV repair gurus lurking?
On Thursday 20 December 2007, Peter Clifton wrote: Hi, I'm fixing (or trying to) a TV for a friend, and wondered if anyone had any wisdom relating to the following symptom. This is a Sony BE-3D chassis, and exhibits an intermittent fault. When its doing it, the picture is still visible, but collapsed (jitteringly) upwards towards the top of the screen. It doesn't stay collapsed for particularly long. The sections of image which collapsed upwards also narrowed horizontally, leading to a tapered looking screen --- |\ /| | \ / | | \___/ | --- (Although this diagram probably exaggerates it somewhat). None of the obvious supply caps tested for bad ESR on my meter (main PSU cap, the various secondary side PSU caps including B+, the flyback derived 200V supply etc.) Even when raster / scan has been lost completely, sound works fine. At one extreme I saw in person today, the vertical collapse left three horizontal lines (R,G,B) separated by an inch or so on the screen towards the top. No picture was visible (and I turned it off). I know this set has a common fault with flyback transformers failing due to internal arcing. I almost convinced myself this was probably the case, but now I'm not so sure. Could it cause the symptom? (It usually supposed to trip the sets overcurrent protect on the B+ line and shut down H drive, throwing the set into standby though - which it didn't seem to do for me today). Unfortunately its been several years since I last fixed a TV, and I don't have my handy box of bits for insulated prodding / light-bulb inserting / freezing / HV testing. I don't even have an oscilloscope here (although I could borrow one from the lab). I'm working with multimeter and ESR meter. I do have the schematics and service manual though, which is a big plus. Best wishes, Look for a common bypass capacitor between the vertical output stage and some point in the hscan stage that also has a resistor between it and the main supply, which if it opened would allow the vertical rise in current to modulate the hdrive amplitude. Also for any medium power resistors that show signs of losing paint, 2 watt fireproof and up types. The contact ferrel on the end connector might not be making good contact with the resistor film. This is a case where the ESR meter like a Capacitor Wizard can be very handy, and so can an oscilloscope. Borrow it. Around the solder joints on the bottom of the scan/hv tranny is a good place to take a low power microscope, looking for solder cracks too. I'd hesitate to condemn the scan tranny itself in an intermittent scenario, normally cuz any kind of a failure there is both permanent, and takes the scan transistor, a big switcher type, out with it in milliseconds. Usually to protect the 50 cent fuse. :) A couple of other things to ponder. Hscan drive circuits are expected to fully saturate the hscan output transistor when its on. If they do not, the heat generated by the transistor will rise very rapidly, often destroying the transistor is just a second or so. Modulation of its drive level for the length of times you are describing would seem to indicate that the transistor may already be damaged. Check the base-emitter forward breakdown with a digital meter, anything on the diode scale of over .8 volts would make me wary, I'd expect to see something below .7 volts but not as low as .6 volts. From an old, almost retired C.E.T. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Where there's a will, there's a relative. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: OT: RS232-TTL level translator in a box
On Tuesday 13 November 2007, Peter TB Brett wrote: On Tuesday 13 November 2007 13:31:40 ED wrote: Not sure if its what you were looking for, however we have been playing with these FTDI chips for a little while now and they have been working great. Basically you plug this little beast in and get a virtual serial port. Works as a USB to serial converter. Drivers for Linux, Mac, and XP, Vista may be a little trouble. As usual when someone mentions FTDI devices, I need to point out that back in '05 I had some potentially *very* expensive problems due to their poor (i.e. close to totally inaccurate) documentation. Also, only the XP drivers allow you to program use the extended functions of the devices, and when I enquired about getting documentation for the purpose of implementing full Linux support they told me to get lost in no uncertain terms. So that's another reason not to use them. Peter FWIW Peter, FTDI has the only serial-usb devices usable with old garmin gps-roadnav, apcupsd and heyu, the linux pl2303 having become broken for those uses back about 2.6.18 or so never resuscitated that I know of. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) A farm in the country side had several turkeys, it was known as the house of seven gobbles. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: newbie, couple of Q's about gschem
On Saturday 13 October 2007, Peter Clifton wrote: First, before I forget, thanks Peter. On Sat, 2007-10-13 at 08:39 -0400, Gene Heskett wrote: Complaint #1 is that the diode bridge symbol is about 1/8th the area of a landscape letter page, occupying many times the real estate that the DPDT relay symbol occupies. And for a newbie, no obvious way to scale it or them to a more pleasing and usable size. Did I miss it in my menu searches? gschem's symbols aren't scalable. Many of the components are drawn larger than you might expect for the size title block which bears a particular paper size as its name (Its size is probably right when taking gschem world coordinates as mils though). Usual solution is to increase the size of the title block you're using for one which matches the aspect ratio of the paper you're going to print on. That or draw your own symbols. Complaint #2 is that while I can see the connection dots in color on screen, they are not nearly so obvious when printed in black white, and it would be very handy if the much older ')' style of non-connecting crossover symbol was available, but again I couldn't find it. It is possible to print in color, I'll answer that under point 3. As for the ) crossover, gschem doesn't support it. You can draw arcs and lines, but if you ever wanted to netlist the output, these wouldn't show up. (See the Add menu). If you use them, a tip for making little arcs small enough. The grips for manipulating them will all overlap as the arc is small. Get the angles / size right from the dialog box when you place the arc, then box-select and use em (edit move) or ec (edit copy) to position them. Also er (edit rotate) might be handy. I assume there is a symbol editor too, but I didn't look very hard for it. gschem is a symbol editor too. You can change the filter in file-open and open .sym files. To draw one, either start from an existing. (You can click a symbol, then go to the hierarchy menu and choose down symbol). Just save somewhere you've got write access, perhaps in your project directory. You'll need to add a component source line to your project's gafrc file. (If you don't have one, just drop an empty file, and place in it the line: (component-library ./) (Or some path to where you saved). For what I wanted to do, it would have been not only nice, but also intuitive, if a symbol when selected and floating, ready to place, would be zoomable with the mouse wheel in order to scale it for a more usable, pleasing size. As it worked, the mouse wheel still zooms the main page, not the symbol other than it followed the main pages size changes too. Thats a nice idea, assuming no-one is so opposed to scalable symbols. Certainly it might be nice as something you can turn on/off. The main issue would be for multiple pin components where each pin has to land on gschem's 100x100 grid. Mmm, that would seem to call for a 'zoomable' 'yes'|'no' attribute in the symbol as a solution for that. No idea how hard it would be to code that up though since its been close to a decade since I coded anything more complex than a bash script, something this machine has quite a few of, doing things I got tired of making typo's while trying to do them by hand. Arthritic fingers that don't always hit the right key accurately don't help... Some of today's parts need 50 and 25 mill grids too. :) Complaint #3, and minor, is that the printout is BW. Even when fed to a color capable printer. This can be changed. This time in a file called gschemrc, drop the line: (output-color enabled) (Or edit the system one installed under $PREFIX/share/gEDA/system-gschemrc, or drop a per user one in ~/.gEDA/gschemrc Did that and found its verbatum, black background all. Turned it back off after one page since epson has raised the price of a black cartridge to over 30 dollars now. Hope this helps. It does, and thanks again Peter. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The chain which can be yanked is not the eternal chain. -- G. Fitch ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
