Re: [time-nuts] Low noise power supplies - dont' use Electrolytics
On Sat, Nov 26, 2011 at 2:13 AM, gary li...@lazygranch.com wrote: At sane temperatures, OSCONs are very good. Who runs their gear hot enough to boil water? National Fire Protection Agency (NFPA) 2007 edition of their design regulations state the electronics worn by Fire Fighters must work at 500'F for five minutes. In the Paper Pusher's mind the Kevlar clothing can withstand those temperatures, therefor anything else in the Universe can too. Never under estimate the bureaucratic mind... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SDR GPS
On Thu, Nov 24, 2011 at 6:19 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: Has any of you played with this: http://www.sparkfun.com/products/8238 Anyone look at the the one from Parallax that Radio Shack is selling for less than $50? http://www.parallax.com/Store/Sensors/CompassGPS/tabid/173/CategoryID/48/List/0/SortField/0/Level/a/ProductID/644/Default.aspx http://www.radioshack.com/product/index.jsp?productId=12302298 It says it is an antenna, do look at the specs closer. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Google NTP Servers and smearing leap seconds...
On Fri, Sep 16, 2011 at 2:36 PM, Hal Murray hmur...@megapathdsl.net wrote: x...@darksmile.net said: You can forget Wall St. firms and Banks for starters. They need sub-microsecond accurate timing as some instruments (Forex) are moving to 10 microsecond latency from order entry to order ack. 10 microsecond latency doesn't say anything about how accurate the time has to be. Does anybody have a good URL on the accuracy requirements of banks and/or stock markets? I expect there are both legal and technical issues. I'd like to understand them separately There are some big names in Banking and Stocks behind the Advanced Message Queuing Protocol (AMQP): http://www.amqp.org/confluence/display/AMQP/About+AMQP http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=amqp http://amqp.org/resources/financial-services Actually Time Nut Grade measurements are not addressed at this level to my knowledge. pbRound Trip/b: The term round trip refers to the process of a peer sending a command to its partner and receiving confirmation that the command is complete. Round trips are necessary for synchronization of world views, however, it is not necessary for a client to wait and do nothing while a round trip occurs or only deal with a single round trip at a time./p /li li pbRound Trip Time (RTT)/b: The term RTT refers to the time taken to complete a round trip. This is described with the following formula:/p pre RTT = 2*latency_network + latency_processing /pre pNote that RTT at the execution layer differs from RTT at the network layer. At the network layer the processing latency is zero resulting in an RTT of twice the network latency. At the execution layer the processing time becomes significant if, for example, processing the command requires sending data to disk. This would be the case with durable messages and the RTT would then include the Broker's disk latency./p /li but I won't be surprised if they are thoroughly tangled. http://www.imatix.com/articles:whats-wrong-with-amqp There is also the even more obscure 0MQ: http://www.zeromq.org/ -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Commercial Assembly - Poll
Since it's a short run, I suspect the per run charges (machine setup and screens) will be a significant part of what would be paid. See what I wrote on my blog sometime ago Is there a rule of thumb for estimating the cost of getting circuit boards assembled?. http://blog.designer-iii.com/contract_manufacturer/20090616-211514-Is-there-a-rule-of-thumb-for-estimating-the-cost-of-getting-circuit-boards-assembled There are design-for-manufacture tips that few ever think of that can lower costs. For example if you are using a 0.1uF cap. all of those caps should be placed on the same side of the board. Some CM's will run one side of the board on one machine, and the other side of the board on the other. If the same part is on both sides the set up fee is higher because you have to move the reel of parts between machines. Also things like don't put 0402 parts between, comparatively, huge tantalum capacitors, because you would have to switch vacuum nozzles. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Parts Selection
On Fri, Mar 25, 2011 at 5:29 PM, Bob Camp li...@rtty.us wrote: I don't see a way to reasonably ship a solder mask with each board. I agree it would be neat, but it would cost ... Solder Stencil actually. The mask is part of the board. Low use stencils are $25: http://www.pololu.com/catalog/product/446 for each one. I'll address some other comments I see in this thread, in this one reply. On the PCB list the consensus is 0402's are the smallest things that can be done by hand. 0603 are no problem at all to do by hand. BGA's are actually easier to do than QFN parts, as long as you accept the board is now not repairable and is a throwaway item. Avoid QFN's if at all possible, especially in battery powered circuits. The flux gets trapped raising leakage currents. It doesn't take a steady hand it takes a while timed hand, drop as pass over not hold and aim. Think Target Shooting rather than holding absolutely still. I expect any Time Nut probably has what it takes to cobble together a video magnifier in their house already, except for maybe the macro lenses, for example: http://www.designer-iii.com/Solder/ made from Wife's video camera, RF Modulator and old color TV. Check out the Toy Store for Cyclops Camera or search for AE10324-ND at http://www.digikey.com . Not the best but works. Works well mounted on old desk lamp base, that has a flexible neck to aim and hold, picked up at the Salvation Army Thrift Store. Also consider there maybe disruptions in the supply chain due to the Japan Earthquake at the fundamental material level, as well has the chip level. Many fabs are still closed due to damage or lack of reliable power. The glue that holds the electronic industry together falls apart, Bismaleimide Triazine (BT) resin shortage. http://blog.softwaresafety.net/2011/03/glue-that-holds-electronic-industry.html -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Problems with Garmin - maybe we should cut them a little slack
On Fri, Dec 31, 2010 at 11:18 AM, William H. Fite omni...@gmail.com wrote: Maybe we should cut these cartographers a little slack. When you consider that Garmin will sell you a map update of the entire northern hemisphere for eighty bucks, we perhaps shouldn't get too wadded up if they miss the exact location of my little bungalow by a couple of hundred feet. Neither my TomTom nor my Garmin will let me enter my street address *at all*! TomTom says my, fake number here, house number 1234, must be in the range of 1,000 to 10,000. Yes, it is telling it must be in the range, that it is already in, and we not let me enter it. Close as I can get is a house on dirt road a half mile up the street. My Garmin has never heard of the road I live on. US 322. My wife did find a road called Lakes to the Sea Highway that the Garmin thinks I live on. No one around these parts have every heard of that road. At work. Garmins take you down a *long* maze of dirt roads into a swamp. There is no winter maintenance on that road. We might find some missing people there in the spring time... In the summer time it is not a bad drive, if you like swamps and dirt roads. A couple of hundred feet could be the difference between life and death if the fire truck or ambulance ends up spending time at the wrong address, for even a short period of time. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Hyperterminal with variable baud rate
On Thu, Nov 18, 2010 at 11:55 AM, Corby Dawson cdel...@juno.com wrote: Are there any terminal programs out there that allow you to select rates other than the standard values? https://sites.google.com/site/terminalbpp/ Select 'Custom'. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB 60 kHz Loop Antenna Progress
On Tue, Oct 19, 2010 at 10:14 PM, Bill Hawkins b...@iaxs.net wrote: As I understand it, 60 KHz information is so slow that phase information is critical. Take a look at the Synchronous Demodulator that is listed with the Black Hole Ant. info. http://www.unusualresearch.com/Sutton/sutton.htm -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB 60 kHz Loop Antenna Progress
On Tue, Oct 19, 2010 at 7:16 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: But then again, avoid the issue and go for a black hole antenna amplifier. I've been gathering information on Black Hole Antennas for a while on my web site: http://www.unusualresearch.com/Sutton/sutton.htm Anyone come across anything new? Always did want to try one for 60 kHz. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Homebrew H Maser
On Sun, Aug 29, 2010 at 7:56 PM, Didier Juges did...@cox.net wrote: I'll dig them up and see if anyone could host them on a website. (Files are quite large!) It would be great if you could upload these to the Manuals page at www.ko4bb.com. That would be great. If the files are really big (over 100MB) and if your internet access is not truly broadband, you may find it more convenient to put them on a CD/DVD and snail mail them to me if you prefer. Try the old DjVu Solo 3.1 program that you can download from here: http://djvu.org/resources/ I've seen it turn 100M page scans into 100K files. If you want to turn the DjVu into a PDF, use the Print command to a PDF driver, such as GhostScript, or Acrobat. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] On low-voltage TAC/TDCs for a GPSDO
On Thu, Aug 12, 2010 at 6:45 PM, J.D. Bakker j...@lartmaker.nl wrote: To start with the context: I'm planning to use a microcontroller with a built-in dual 12-bit 2MSPS ADC. That sounds like it is an Atmel XMega part. Do make sure you read the data sheet errata section, as some parts in the XMega Ax line have nasty A/D problems. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Did my Tbolt die ?
On Sat, Jul 17, 2010 at 5:17 AM, Neville Michie namic...@gmail.com wrote: I have had problems with TBolts on PCs. The COM port assignments seem to be a bit volatile, plug in a different mouse or other user and you may find the COM port has been assigned to it. I have never been able to confidently cope with this problem, I just keep hacking the system and sooner or later I get the COM port right with the right settings and all is well. There seem to be up to 3 layers to get right. This may be because I use USB to serial converters or just be inherent to the later Windows OS. cheers, Neville Michie If you drill down under the Advanced button in the Serial Port Control panel area you can reset the Windows COM port for a single port. If you know the port is not in use, ignore the message that tells you that it is in use, when you change the port number. You can also search the Windows registry for the COM Port Arbitrator. It is a 256 binary bit map of the assigned, and the next to be assigned, COM port. That is where you reset the ever incrementing COM port number. If you are using a USB converter and want it to stay put, do the following. This should work for non-FTDI devices, that have serial numbers, just match the VID/PID. From FTDI Support: === Hello, What you will need to do is uninstall the driver for the FTDI device. Now you will need to create a binary value in the registry by doing the following: Go to START and select RUN Type regedit in the filed and select ok to get into the registry Add a REG_BINARY value called IgnoreHWSerNum to the registry and setting it to 01. This value is held in the registry key located at: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\UsbFlags\IgnoreHWSerNum (Device VID, PID and interface} For a default FTDI device ID (VID 0x0403, PID 0x6001), add the following registry REG_BINARY value set to 01: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\UsbFlags\IgnoreHWSerNum0 4036001 Now install the driver again. After this the com port should not increment. Regards James Leary Support Engineer FTDI Ltd === If those don't help I can tell you the other darker places of the registry to examine and poke at. I had to make one of my programs Idiot Proof. Customers kept calling me up and asking me What COM port do I have?. I always wanted to respond How #$)*#)$ should I know? It is your computer. [It happened a lot, this group of customers were not Computer People.]. Instead I wrote my programs to always find the correct COM port for the customer. I need to turn that into a DLL so other people can use it. Programming is a race between making programs Idiot Proof, so that any Idiot can use it, and the Universe building bigger and better idiots. The Universe is winning. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS receiver stuck at South Pole :)
On Thu, Apr 15, 2010 at 8:08 PM, Hal Murray hmur...@megapathdsl.net wrote: I've got a Garmin GPS 18 USB. (18, not 18x) It's inside. I'm not surprised when it fades out. At first, I thought it was just giving a garbage location while trying to find some satellites, but now that I've plotted it... It took about 7 hours to fly from here to the south pole. Maybe it wanted to check out the Penguins in Gars O'higgins Antartica?: http://www.martingrund.de/pinguine/pinguincam1.htm Pictures are updated live every 15 minutes, except at night to save fuel. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fw: Re: Fluke1 Monitor
On Thu, Feb 18, 2010 at 7:26 AM, Bob Camp li...@cq.nu wrote: It is amazing just how much stuff that's normally up for sale is missing at the moment. It is EBay's goal to drive out any small sellers, they only want the big power sellers now. Look at the EBay forums and you see that the small sellers would like to leave en'mass but they have no place to go where there are buyers. My wife, a small seller that sells my leftover Eval Boards, said she was not going to sell anything until this fall to see how these latests changes shake out. As a seller now if you get just one negative hit you get your account suspended. Doesn't mater if they buyer is lieing or not, which is becoming common. EBay has become a very hostile and crime ridden place, it is not the mecca that it once was. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] AMC-123 patent
On Sat, Feb 20, 2010 at 4:33 PM, Gerhard Hoffmann dk...@arcor.de wrote: Rick Karlquist wrote: Fortunately, there is a paper copy of the 1989 Anzac catalog in the N6RK technical library. Not everything is on the internet. The patent number is: 3,624,536 go to http://www.pat2pdf.org/, enter the number and fetch the patent :-) Best place to get patents in PDF is the European Patent office at http://ep.espacenet.com . When you do a Number Search enter the appropriate two letter code like US for a US patent right before the number. http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOCadjacent=truelocale=en_EPFT=Ddate=19711130CC=USNR=3624536AKC=A To get the PDF ignore most of what you see, click on Original Document then click on Save Full Document that appears just to the left and down from the tab. Seems they have changed the location of this recently. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] True to there word. - Fancy WWVB
On Mon, Feb 8, 2010 at 8:40 PM, Bob Camp li...@cq.nu wrote: I assume that you are going to have to train your loop to expect the ID shifts and time markers. Again, they are predictable. Would it not be easier to use the WWVB Zero-Crossings to sync something? Then the power shifts should not mater. It's just software You must be a hardware person... :-) -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Test Equipment Tables
If you are looking for massive tables on the cheap, you can indeed build them. The only real drawback is that it's a build in place item. You aren't going to take it with you when you move. There are various versions of that table scattered all over the US. My work bench is two 2 thick, eight foot long planks, bolted to two two-drawer filing cabinets, then covered with anti-static-mat. The anti-static-mat is screwed into the wood. So when it comes time to move this you unscrew and unbolt and you are on your way. As added bonuses you have four filing cabinet drawers to keep manuals and schematics in. You can see it here: http://www.designer-iii.com/Solder/ Two drawer cabinets that you can buy today are a bit shorter so they need some cement blocks hidden under them, or double up on the planks. I've not seen anyone address the anti-static issues in setting up a workbench... The Preface to Murphy's Law: We, the willing, Lead by the unknowing. Are doing the impossible for the ungrateful... We have done so much for so long... With so little... We are now qualified to do anything... With nothing... Forever! -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] chip scale atomic clock
On Sat, Dec 26, 2009 at 8:23 AM, Ronald Held ronaldh...@gmail.com wrote: I read about this a while ago. Researcher Time Line Translations were explained here a few days ago: http://www.xkcd.com/678/ The mouse-overs always have interesting comments... -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] are any time-nuts also random-nuts?
On Thu, Dec 24, 2009 at 3:24 PM, Scott Newell new...@cei.net wrote: At 01:57 PM 12/24/2009, saidj...@aol.com wrote: No need for that, just buy all ~18 million tickets (would cost $18 million in the US) if the jackpot is ~$60 million or higher, which it often is... To improve your odds in Lotto games look up Wheeling Systems, they have been around for a long time. Back when I had money, that is before I got married, I'd buy hundreds of ticks at a time based on the appropriate Wheel. I broke even. Didn't have the $ to buy all the possibilities. Most people can't even say they broke even on the lottery... -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] are any time-nuts also random-nuts?
What he has discovered, with the aid of a spreadsheet, is that when the 6 winning numbers are announced, they usually sum to a number somewhere in the range 130 to 170. Very rarely is the sum very low or very high. Gail Howard has written books and 'wheels' on this system. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Invariance
Some researches is about to measure the change of universal constants as universe expands. Time and Spacetime: The Crystallizing Block Universe http://arxiv.org/abs/0912.0808 The nature of the future is completely different from the nature of the past. When quantum effects are significant, the future shows all the signs of quantum weirdness, including duality, uncertainty, and entanglement. With the passage of time, after the time-irreversible process of state-vector reduction has taken place, the past emerges, with the previous quantum uncertainty replaced by the classical certainty of definite particle identities and states. The present time is where this transition largely takes place, but the process does not take place uniformly: Evidence from delayed choice and related experiments shows that isolated patches of quantum indeterminacy remain, and that their transition from probability to certainty only takes place later. Thus, when quantum effects are significant, the picture of a classical Evolving Block Universe (`EBU') cedes place to one of a Crystallizing Block Universe (`CBU'), which reflects this quantum transition from indeterminacy to certainty, while nevertheless resembling the EBU on large enough scales. - George F. R. Ellis, Tony Rothman (Submitted on 4 Dec 2009) -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna and lightning
Just one little wire that's not tied into the system provides a path that will let damaging currents come in through any other wire, no matter how well protected they are. I had one strike here that came *up* out of our 300 foot deep water well, when a tree several hundred yards away took a direct hit. You would think a 300 foot deep metal pipe filled with water would be a good ground... -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 4046 variations (was EPE GPS....)
The part might look wrong without this information. One case was a 3.15A fuse in series with a 27R resistor at the 28V supply input. The fuse can never blow (no the aircraft didn't have 115V 400Hz supplies). The reason was a pater exercise to obtain intrinsic safety approval without formal testing. The rules said a specific type of fuse must be used at the input, the minimum rating of that approved type of fuse was 3.15A! I've been down a similar road. We designed a low power radio remote control to run some Coal Mining equipment. The regulatory bureaucrats in the UK Coal Mining industry for intrinsic safety told us we *had* to use a particular power diode, don't recall the number any more, or they would not approve our product. That diode leaked more current that our product took while transmitting! If we wanted to use any modern diode, they would let us do that if we paid them nearly a hundred grand to get it tested and approved, and listed by them as an approved component. So we used their diode and put up with the constant complaints about short battery life. :-( -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Don't let the magic hair out...
I assume that in time better grade capacitors will work their way into the manufacturing world. Counterfeit electronic parts have become the newest business model in some circles. The problem is getting worse. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FreeBSD, NetBSD, or Minix-III?
A 33.31 format would buy us a century, still allow us to get nanoseconds right, but it be computationally inconvenient and looks messy, so people balk at it. Anything wrong with TAI64NA? http://cr.yp.to/libtai.html libtai is a library for storing and manipulating dates and times. libtai supports two time scales: (1) TAI64, covering a few hundred billion years with 1-second precision; (2) TAI64NA, covering the same period with 1-attosecond precision. Both scales are defined in terms of TAI, the current international real time standard. TAI64NA in FPGA? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FreeBSD, NetBSD, or Minix-III?
I'm not out to start any kind of OS war here, I'm simply curious as to alternatives. On Fri, May 15, 2009 at 12:02 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: ... which you can read more about in my paper from 2002: http://phk.freebsd.dk/pubs/timecounter.pdf Anyone know how NetBSD stands in regard to time services? http://www.netbsd.org/ Anyone ever look at Minix-III (Minix-I was the progenitor to Linux)? Seems like it would be easy to make a decent time server, on embedded hardware with it. Past iterations of the Minix-III website gave a watch as an example small embedded system it was meant to power. http://en.wikipedia.org/wiki/MINIX_3 http://www.minix3.org/ -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FreeBSD, NetBSD, or Minix-III?
On Sat, May 16, 2009 at 9:21 AM, Chuck Harris cfhar...@erols.com wrote: Bob Paddock wrote: Anyone ever look at Minix-III (Minix-I was the progenitor to Linux)? Seems like it would be easy to make a decent time server, on embedded hardware with it. Past iterations of the Minix-III website gave a watch as an example small embedded system it was meant to power. Why do you think Minix-III would be a good candidate for a time server? Minix-III is based on the microkernel approach of keeping things small and fast. Take a look at the web site. http://www.minix3.org/ A watch isn't exactly a challenge to an operating system. True. The challenge is putting the OS *in* the Watch, as the Embedded System that runs it. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FreeBSD, NetBSD, or Minix-III?
I think there is more use of microkernels (eCos, RTEMS, Erlang, etc.) in the embedded world. The environment is more constrained, so reducing the footprint is useful. There is also the new µC/OS-III (yes, three) that provides near zero interrupt disable time. µC/OS-III has a number of internal data structures and variables that it needs to access atomically. These critical regions are protected by locking the scheduler instead of disabling interrupts. Interrupts are disabled for almost zero clock cycles, ensuring the RTOS will be able to respond to some of the fastest interrupt sources. In the day job I'm designing near pager size devices, heading down to watch size devices. Current project has a U-Blox GPS hooked up to a AVR XMega Event System pin. Any Time Nut suggestions on what to do with it? Has 120x32 bit LCD display, and small speaker, also. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FreeBSD 7 ntp server
I'm thinking about, for example, stock trading where the first bid wins. Sub-second resolution is needed there, I think. Advanced Message Queuing Protocol (AMQP) is what is used in some big brokerage firms. http://jira.amqp.org/confluence/display/AMQP/Advanced+Message+Queuing+Protocol Specs are here: http://jira.amqp.org/confluence/display/AMQP/Download The datetime type encodes a date and time using the 64 bit POSIX time_t format. Also http://cr.yp.to/time.html maybe of interest to Time Nuts. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] US Shipping Was huntron tracker advice
If you have ever been on the other side of an ITAR investigation, you would rightly conclude that it isn't safe to do anything other than scrap and destroy US surplus materials... which is precisely what they want you to do. In a past life I designed Coal Mining Equipment, back when the 68000 was a new part to the world. China bought some of our equipment using the 68K. We had to jump through hopes to prove that this embedded system could not launch a missile etc. to the State Department. The interesting wrinkle was that the delivery truck wrecked on the way to the mine in China, in China. Some of our equipment was damaged and so was the *Cray-1* that we discovered was on the truck too. We never could find out what it was on that truck for. An obscure site if you do what to see what is going on in Missile tech is http://www.mdatechnology.net/ and http://www.mda.mil/mdalink/html/mdalink.html . -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I want a good micro-controller
Beware, programmers have turned to screaming, blithering idiots with bits of their brains oozing out all of their orifices just by glancing at that page. Worse than writing a Web Server in the language BF? The B stands for Brain, and I'm not going to put the F on a family oriented list like this one. The following program prints Hello World! and a newline to the screen, from the Wikipedia entry: ++ [ +- ] this loop sets the next four cells to 70/100/30/10 ++. print 'H' +. print 'e' +++. 'l' . 'l' +++. 'o' ++. space +++.'W' .'o' +++. 'r' --. 'l' . 'd' +. '!' .newline That is not a badly formated message, that is what the cost is... At least it doesn't require a custom keyboard to code it. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Help with HP 8640B generator
The cubicle? Anti-Productivity Pods: Cubicles as Dilbert so astutely noted. For my money the most important work on software productivity in the last 20 years is DeMarco and Lister's Peopleware (1987 Dorset House Publishing, NY NY). For a decade the authors conducted coding wars at a number of different companies, pitting teams against each other on a standard set of software problems. The results showed that, using any measure of performance (speed, defects, etc.) the average of those in the 1st quartile outperformed the average in the 4th quartile by a factor of 2.6. Surprisingly, none of the factors you'd expect to matter correlated to the best and worst performers. Even experience mattered little, as long as the programmers had been working for at least 6 months. They did find a very strong correlation between the office environment and team performance. Needless interruptions yielded poor performance. The best teams had private (read quiet) offices and phones with off switches. Their study suggests that quiet time saves vast amounts of money. Think about this. The almost minor tweak of getting some quiet time can, according to their data, multiply your productivity by 260%! That's an astonishing result. For the same salary your boss pays you now, he'd get essentially 2.6 of you. -- Jack Ganssle in The Embedded Muse #25. You can find related comments at http://www.softwaresafety.net . ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Capacitive temperature sensing
Bruce, very interesting. I didn't know capacitive sensors went down that low. That could be useful in other areas. I searched google but found nothing. Do you have any urls? http://www.eetimes.com/showArticle.jhtml?articleID=175801455 EE Times: SENSORS: Quake detector preps for market ... We are finishing the prototype now, said Les LeZar, president of Zoltech (Van Nuys, Calif.). As it stands, its case is just under 2 feet tall and houses an 18-inch pendulum. Peters' design uses a novel means of varying the surface area of a capacitor. Rather than varying its gap as in standard capacitive sensors, Peters' design varies the capacitor's surface area. Because the capacitor's gap is constant, detection is not accompanied by a drop-off in sensitivity, as is the case with other capacitive sensors. Most of those become less sensitive when their gap widens. I have a patent on several variations of what I call a symmetric differential capacitive sensor — what microelectromechanical-systems designers call 'fully differential,' said Peters. Since sensitivity and dynamic range don't have to be treated as a design trade-off — as in traditional capacitive sensors — Peters' design sets sensitivity by the constant size of the gap. By changing the surface area, it separately determines dynamic range. In a nutshell, the dangling pendulum has a grounded Faraday shield on the end, hanging between the four plates of a symmetric differential capacitor wired in a diamond like a Wheatstone bridge, but with series diodes and parallel resistors to rectify its output into direct current. Parallel printed-circuit boards house the plates of four square capacitors. The grounded Faraday shield initially covers all capacitors equally. When the Faraday shield is jiggled, it increases the surface area of two capacitors on opposite sides of the bridge, and decreases the other two opposing capacitors' area, thereby giving the bridge its differential sensitivity. A 50-MHz signal is then pumped across two opposing capacitor leads in the bridge, while the differential inputs to the sensing operational amplifier are wired to the other two opposing capacitor leads. ... -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I want a good micro-controller
any ARM7 outperforms the best PIC in price and performance :) http://beagleboard.org/ Get them from DigiKey, $149. http://dkc1.digikey.com/us/mkt/beagleboard.html The USB-powered Beagle Board is a low-cost, fan-less single board computer utilizing Texas Instruments' OMAP3530 [ARM] application processor that unleashes laptop-like performance and expansion without the bulk, expense, or noise of typical desktop machines. Beagle Board is based on an OMAP3530 application processor featuring an ARM(R) Cortex™-A8 running at up to 600MHz and delivering over 1,200 Dhrystone MIPS of performance via superscalar operation with highly accurate branch prediction and 256KB of L2 cache. Focal to Beagle Board experience is the high-speed USB 2.0 on-the-go (OTG) port that can be utilized to provide power to the board or to deliver highly flexible expansion. Standard PC peripherals can be connected to Beagle Board using the USB with a mini-A to standard-A cable adapter, DVI-D using an HDMI to DVI-D adapter, or through the MMC/SD/SDIO connector enabling a complete desktop experience. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Power supply for Thunderbolt
On Thu, Aug 7, 2008 at 5:59 AM, Peter Vince [EMAIL PROTECTED] wrote: It may be possible to stack 3 low ESR super capacitors in series (maximum voltage rating is around 2v -2.5V those with higher ratings are actually series connected stacks) to do this but this is a relatively expensive proposition. Presumably you would need parallel resistors to ensure an even voltage split? And if so, are we talking about kilohms or megohms? Current is probably to low for this application, but it is worth noting: LTC3225 - 150mA Supercapacitor Charger Features * Low Noise Constant Frequency Charging of Two Series Supercapacitors * Automatic Cell Balancing Prevents Capacitor Overvoltage During Charging http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1098,P84365 The part has been tested up to 400 Farads. Anyone ever look at using the LT1533 - Ultralow Noise 1A Switching Regulator as the basis of a power supply design? http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1032,P1126 -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What is a Time-Nut grade Zero Crossing Circuit?
Jitter specs assume a logic waveform input, not a sine wave input. Many jitter specs refer to pattern jitter of data, which does not apply to clocks. Also, jitter increases at low frequencies in practice, even though in theory it should not. Like I said, this topic is very tricky. How exactly does zero jitter? I understand that the logic detecting the zero voltage point of a sine wave might not be perfect. However if the circuit is truly a Zero Crossing Detector, things like the frequency and amplitude variations of the sine wave are irrelevant, as long as the bandwidth is sufficient to the design of the detector. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] What is a Time-Nut grade Zero Crossing Circuit?
Can you point me to a Time-Nut grade Zero Crossing circuit that I can feed a Actel Igloo FPGA (It doesn't like sine waves)? For the sake of discussion the source signal is a ThunderBolt at 10 MHz. The FPGA is rated to 350 MHz, so no need to have a 5. GHz Zero Crossing circuit. ;-) The FPGA has several interface styles, so we are not limited to just TTL or CMOS. Suggestions? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Double ovened 10811-60158 on ebay
I keep wondering if not a passive oven (metal box, insulation, metal box) would be sufficient. Large metal reflectively lined thermos bottles are worth considering. You do end up with a lot of long skinny circuit boards that way. Peltier based thermoelectric cooler's from Big Box Stores can also be pressed into service as temperature cycling oven, or stable temperature environment, with the addition of proper regulation loop. See this long outdated paper: http://www.designer-iii.com/cco/HBridge.pdf http://focus.ti.com/lit/an/slua202a/slua202a.pdf Closed-Loop Temperature Regulation Using the UC3638 H-Bridge Motor Controller and a Thermoelectric Cooler. Next time you have to endure shopping with your wife keep your mind busy by asking What can I use 'that' for? for everything you see... The Preface to Murphy's Law: We, the willing, Lead by the unknowing. Are doing the impossible for the ungrateful... We have done so much for so long... With so little... We are now qualified to do anything... With nothing... Forever! -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Frequency divider design critique request
There are usually some BNC bulkhead connectors on eBay that terminate in SMA/SMB/SMC pigtails, which are great for panel mounting. Not directly related to this design, but it made me wonder about something. If you are building a multiple output system and channel phase to channel phase was important, would pigtails like this cause problems due to different delay times because of slight variations in length? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Frequency divider design critique request
The CPLD's (unlike the FPGAs) are single chip solutions. There are many single chip FPGA solutions today from several different companies. If you are in the US and near a Avnet office you can pick up a Actel Igloo Icicle eval. board/programmer for $49. They are giving them out at the Actel Power seminars being held in July and August. I'll be at the one in Cleveland next week if anyone is there. Don't know if this URL will work or not: http://www.em.avnet.com/evs/home/0,4582,CID%253D47005%2526CCD%253DUSA%2526SID%253D32214%2526DID%253DDF2%2526LID%253D32233%2526BID%253DDF2%2526CTP%253DEVS,00.html?SUL=actellowpower -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt and USB to RS232 converters
On Monday 07 July 2008 02:10:35 am David Smith wrote: I'm aware of those, but the next new USB serial device you plug in will still be the next higher number. It is the counter for this number I've not been able to locate. I've just sorted this problem on another thing I was doing, although I was only up to COM14! It seems there are hidden hidden devices. Have a look at this: http://support.microsoft.com/kb/315539 Been There Done That, some time ago, but thanks for reminding me. I want to get all of these tips on my website related to this USB COM port saga. Note that even plugging the same USB-RS232 converter into another USB port on a hub will create a new COM port. I've dug into it enough that I understand why, but I'm still looking for where that new COM port number is coming from. Still trying to find that counter. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt and USB to RS232 converters
On Sun, Jul 6, 2008 at 11:57 AM, Arnold Tibus [EMAIL PROTECTED] wrote: Hello all Thunderbolt enthusiasts, Thunderbolt Monitor does show all the assigned ports at the right side column for com ports 1 to 16. A tip for anyone that might be designing software. Don't put a fixed limit on the USB virtual COM ports like 1 to 16. Make a pull down that show what ports are really populated via the SetupDI API. The next new USB COM port I plug into my development machine is going to be assigned COM44! Anyone know where in the registry to reset the ever incrementing new COM number? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt and USB to RS232 converters
In the device manager, choose View: Show hidden devices. The grayed out devices have once been, but are no longer, connected to your machine. Remove the ones that you no longer care about. You can also remap the comport-numbers in the properties of the serial port devices, use the button Advanced... there. I'm aware of those, but the next new USB serial device you plug in will still be the next higher number. It is the counter for this number I've not been able to locate. These are the things that make me happy to be using Linux for most of my electronics stuff ;-)... At this very moment I'm wearing a T-Shirt that says Geek by Nature on the front and Linux by Choice on the back. :-) It is only at the day job where IT told me We are a Windows shop, Linux is nothing but a toy that I'm forced to use Windows (Resume anyone?). Funny I thought we were a company that made Fire Fighting equipment, not a shop that made Windows... :- -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt controllers
A very minimal controller might be an AVR Butterfly. It only has a 6 character display and joyswitch. Rather not up to the task, There is the newer DB101 with the 128x64 bit map display. http://www.atmel.com/dyn/Products/tools_card.asp?tool_id=4221 I think they really did a botched job on the RS232 interface, but everything else is well buffered. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New leap second
On Friday 04 July 2008 03:07:47 pm Chuck Harris wrote: Well, yes. The Earth expands from the heat, rotation slows, and we get another leap second - as we watch symptom after symptom occur while being unable to come to consensus on what to do. I say that we take up the issue with the Sun. Clearly it is also causing global warming on Mars. http://www.prisonplanet.com/articles/november2006/161106suvjupiter.htm SUV's On Jupiter? Are humans responsible for climate change on the outer reaches of the solar system, or is it the sun? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PCB design questions
On Monday 02 June 2008 02:19:52 pm David C. Partridge wrote: I'm now thinking ahead to the PCB requirement... http://focus.ti.com/lit/an/scaa082/scaa082.pdf http://www.ti.com/litv/pdf/scaa082 Application Notes Abstract High Speed Layout Guidelines This application report addresses high-speed signals such as clock signals and their routing and gives designers a review of the important coherences. With some simple rules, electromagnetic interference problems can be minimized without using complicated forumulas and expensive simulation tools. Section 1 gives a short introduction to theory, section 2 focuses on practical PCB design rules. Either section can be read independently. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] quick and very dirty phase comparator
Since I am well familiar with the Analog Devices DDS circuits, this has been my very first idea. The most simple one for that purpose would be a AD9851 (180 MHz, 32 Bit, built in clock multiplier). But when I used the DDS design tool available on the AD web pages I received a big warning saying that using a clock X multiplier frequency that is a near integer of the output frequency generates lots of unwanted spurs. Which was new to me since I do so in my GPSDO but should they not know better? This is why I dropped the thoughts on DDS. Some AD DDS chips have a SpurKiller channel built into them. See page 3.42: http://www.analog.com.ru/Public/HS%20Systems%20Part%203%20Speaker%20Notes.pdf -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PCB design questions thread II
On Monday 02 June 2008 02:31:18 pm Patrick wrote: I have wanted to fabricate my own PCBs for several years now but I have never made an attempt. I am set up here to do silk screening and I have ovens and a hot-air soldering iron. Has anyone else tried to fabricate their own boards or is the price of farming the work out just so low now? I've played with doing them at work. Found it better to just farm them out to the prototype house. It is tough to get any real consistency from week to week. If anyone has farmed out work, could you please feedback as to the entry level costs and if possible, some suggested companies? Cheapest place I've come across for easy boards with 10mil or large lines is this one, but I've not used them yet (probably next month I will): http://www.futurlec.com/PCBService.shtml 1. Surface mount or through hole? I don't have a re-flow oven (or even a hot air soldering system), so my inclination is to use through hole SMT is actually easier if you have a good magnifying system. I use macro-lenses on the wife's Cam-Corder: http://www.designer-iii.com/Solder/ Looks better than the picture of the screen shows in reality. http://www.micromark.com/ has the type of tools that you need, like insulated and cross-tweezers (squeeze them to open them, the reverse of normal tweezers) etc. Pick up a small convection oven at Wal-Mart or such place. If your making several get a Stencil: http://www.smtstencil.com/ http://www.customlasercutting.com/ Will using through hole cause me grief? In the long term, yes. A lot of older TH parts have not been updated to ROHS (Lead Free) and they never will be, they will be discontinued at some point. Virtually all new parts are SMT. 2. How many layers? In an ideal world with money no object, if I understand the current art correctly, I think I'd probably aim for a five layer I assume that is a typo? You can not have an odd number of layers. In this current 3D reality each layer has two sides. :-) board with Vcc, Digital Ground and Power Ground being separate internal planes, and trace routing on the top and bottom of the board with as few vias between top and bottom as possible. Does that sound right? Separate ground planes, or split ground planes are a bad idea in this context. Always think about where the return current is going to flow. Read the Analog Devices seminar notes on the subject. http://www.analog.com/analog_root/static/library/technicalSeminarSeries.html is the link to the books but you can find the chapters on line. Read 7a 7b if nothing else: http://www.analog.com/en/DCcList/0,3090,1073%255F%255F961,00.html -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PCB design questions thread II
On Monday 02 June 2008 04:53:17 pm [EMAIL PROTECTED] wrote: Not the cheapest, but great for professional proto's when quality trumps cost (above 1GHz, one source FR4 is totally different from another sources FR4...) Anyone have suggestions for Metal Core Protype Boards? Used in high power LED applications. I know of this one, are there others?: http://www.protoexpress.com/content/speciality.jsp http://www.cif.fr/new/produits_aff.php3?cat=1scat=3sscat=89p=211 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PCB design questions thread II
How do you cope with SMT parts (eg high frequency ADCs) with metal thermal transfer /ground connections under the package itself? How to succeed the first time with ultra-small QFN packages http://www.wirelessnetdesignline.com/showArticle.jhtml?articleID=202800018 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thoughts on IR thermometers?
On Tuesday 27 May 2008 11:31:49 pm Patrick wrote: I tried to use a cheap IR thermometer to do some quick, pre-circuit analysis tests, a couple of years ago on a particular job. It went bad, the laser did not even line up with the area being measured, I missed a burning hot capacitor and wasted a lot of time. http://www.towerhobbies.com/ has several Temp Guns in the $25 to $50 range. I was thinking about buying a better one this time. Does anyone have any suggestions? Melexis MLX90614 is a Digital plugplay Infrared thermometer in a TO-39 can. http://www.melexis.com/ProdMain.aspx?nID=615 The object temperature can range from -70 to +380'C. You can get them from Future's Component Store. http://www.componentsuperstore.com Have two on the bench here, but have not fired them up yet. I had a hell of a time trying to read my Son's temperature last night when he had a fever, anyone tried one of these out on their children? They have a medical grade one, also Automotive grade ones. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Plotting csv files
Does anyone has some nice software that will easily plot a csv file. I do need to be able to change the vertical scale rather than have it autorange. http://ploticus.sourceforge.net/doc/welcome.html -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] favorite microcontroller module?
On Wednesday 20 February 2008 11:53:23 am Chuck Harris wrote: I doubt it, the audience of these two devices is quite different. The 6805 family could address 64K external RAM/ROM/IO. Not sure what device you are describing, but it is not a 6805. I cannot imagine what lesson they needed to learn. They made a line of extremely easy to use microprocessors that are about as cheap as the package they come in. I should be so smart as they. Chuck, I'm curious to know what other micros you have programmed? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] device as sniffer/ promiscuous mode GPIB devices?
On Monday 28 January 2008 08:19:40 am Patrick wrote: I rebuild and resell lab instruments. My customers are doing great work finding cures for diseases. The software to control their instruments cost between 5-40K and is hyped up garbage that eats up their meager budgets. I desperately, desperately want to write an open source replacement. http://www.iftools.com/ctb.en.html is an Open Source driver based on the wxWidgets tool kit. http://www.wxwidgets.org At this time CTB supports RS232 and GPIB (IEEE488) for Linux and Windows95/98, NT, Win2k and XP in a transparent way. That means that the program code for read and write via RS232 and GPIB is exactly identical for Linux and Windows. Does anyone have experience with any promiscuous mode devices? Under Linux would be even better, if possible? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Super Regulator links
On Thursday 13 December 2007 09:47:36 pm Bruce Griffiths wrote: Matt Ettus wrote: Can you explain to me the use of fast recovery diodes if you are going to put capacitors across them? Even with the snubber networks the reverse conduction time of the fast recovery diodes is considerably shorter than when a standard recovery rectifier is used. Why not use Cree's Silicon Carbide No Recovery Time diodes? http://www.cree.com/ Digikey has them. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timing on Ethernet
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY On Sunday 05 August 2007 12:13, Poul-Henning Kamp wrote: We found the best waveguide experience was in the range of 300 to 420 MHz, but the distance is very limited, hundreds of feet at most. The main problem at different frequencies is the material becomes absorptive at lower frequencies, or reflective at higher frequencies causing to much mutilpath distortion. Most mines are in coal or metalrich rock, wouldn't that make your experience more pessimistic than the tunnels at CERN which, as far as I remember, is in pretty 'worthless' rock ? To get to the Coal Face there are miles of tunnels that have neither coal nor metallic bearing Rock. Radio transmissions there don't do much better than near the Coal/Metallic Rock. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timing on Ethernet
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY On Saturday 04 August 2007 23:54, Thomas A. Frank wrote: Ah, but what if one used the tunnel itself as a waveguide, and propagated an RF signal down it? For many years I designed Coal Mining Equipment, I can tell you from real world experience that it does not work that way. We found the best waveguide experience was in the range of 300 to 420 MHz, but the distance is very limited, hundreds of feet at most. The main problem at different frequencies is the material becomes absorptive at lower frequencies, or reflective at higher frequencies causing to much mutilpath distortion. Look at my site http://www.wearablesmartsensors.com/ under the 'Challenge' section and the blog there for some related information. You can find the results of some of the past real world underground tests here: http://www.msha.gov/techsupp/mcelroyminetestreport.pdf The Mine Safety and Health Administration formed a committee to evaluate communication and tracking system technology that could be adapted for use in underground mines. NIOSH has a test Mine near Pittsburgh if your inclined to test something. We've just started to look into some old/obscure/esoteric ways of transmitting signals underground. Which we hope will solve this problem, if we can overcome some funding and time issues. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timing on Ethernet
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY On Friday 03 August 2007 07:22, Pablo Alvarez Sanchez wrote: At CERN we are considering the possibility of using Ethernet as a real time field bus. There are a couple of projects that have already gone down this road, for one: http://www.rts.uni-hannover.de/rtnet/ Related are, but these are more at the operating system level than the line timing level: http://www.xenomai.org/index.php/Main_Page https://www.rtai.org/ On my assumption that you mean Hard Real Time: Have you looked at FlexRay and/or TTP? Standard communications to be used in the 2008 model year in most cars. Several chips support FlexRay today. Also used in by-X controls, like Fly-by-wire, break-by-wire etc. You can get chips for FlexRay from various players today. http://en.wikipedia.org/wiki/Time-Triggered_Protocol http://www.tttech.com/ http://en.wikipedia.org/wiki/FlexRay http://www.flexray.com/ Come to think of it I don't recall ever seeing TTP or FlexRay mentioned here on the Time-Nuts list? They get into things like: The clock drift must be no more than 0.15% from the reference clock, so the difference between the slowest and the fastest clock in the system is no greater than 0.3%. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Why Cesium and Rubidium only
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] On Friday 27 July 2007 04:14, Dr Bruce Griffiths wrote: 22GHz, (15GHz) (~40.5 GHz) than either the caesium (9.192GHz) or rubidium (6.8GHz) Anything happening in the THz range, that anyone knows of? -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] ? phase comparison or other device
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] On Saturday 30 June 2007 10:15, Dr Bruce Griffiths wrote: Not true, there's nothing magic about amplifier saturation, any means that limits the amplifier output whilst dropping the small signal gain to a low value will have exactly the same effect. The AD8036 and AD8037, from Analog Devices, are wide bandwidth, low distortion clamping amplifiers. The AD8036 is unity gain stable. The AD8037 is stable at a gain of two or greater. These devices allow the designer to specify a high (VCH) and low (VCL) output clamp voltage. The output signal will clamp at these specified levels. http://www.analog.com/en/prodDesc/0,2895,AD8036%255F0,00.html AN-402: Replacing Output Clamping Op Amps with Input Clamping Amps (pdf, 57,313 bytes) http://www.analog.com/UploadedFiles/Application_Notes/374941256AN-402.pdf So far most clamping amplifiers have relied upon an output clamping architecture and are called output clamp amps (OCAs). A new architecture called an input clamp amp (ICA) offers superior clamping accuracy and lower distortion. A diode clamp in the feedback path will cut the noise gain to 1 when either diode turns on. The following diode clamp across the filter capacitor will reduce the noise gain to a very small value when it turns on. Both diode clamps and internal saturation will still produce some output noise although not from the amplifier input stages. Improperly done diode clamps can significantly increase harmonics. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] ? phase comparison or other device
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] These devices are a little noisy below 100Hz. Rather than constantly battle the there is to much noise, what are your thoughts on deliberately injecting out-of-band noise? As an example: http://www.analog.com/UploadedFiles/Application_Notes/319765654AN-410.pdf Overcoming Converter Nonlinearities with Dither The distortion produced by a diode clamp is immaterial when one is only interested in the zero crossing time. It depends on where the harmonics fall. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] C-Max filed Chapter 11
For anyone with interest in C-Max's Time Receiver products, my Sales Rep. for C-Max forwarded this message from their boss yesterday: C-Max filed Chapter 11. Do not sell any longer!! Their old site: http://www.c-maxgroup.com/home/index.php refers to a new site: http://c-max-time.com Both sites look exactly the same to me. DigiKey still has some modules, and loop sticks in stock. I'd get them before they are gone if you need them. I have no way of knowing if there will be any more in the future. http://www.digikey.com -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] LF time signal emulation
On Monday 30 April 2007 11:00, Brooke Clarke wrote: I think the crew from what was called Temic has formed a new company called C-MAX. Here is their web site: http://www.c-maxgroup.com/home/index.php Their parts, and ~$30 evaluation module, are available from DigiKey. They do sell a simulation transmitter, don't know if you can get that from DigiKey. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] 10MHz to 32MHz?
On Monday 23 April 2007 03:56, Don Collie wrote: The thing that puzzles me is: why is the plot of VCO voltage versus time different when locking from below to locking from the same initial frequency difference when locking from above. It`s a pity you can`t predict PLL lockup characteristics using linear algebra - or do you need a particular kind of phase [or frequency] detector that would enable you to do this? Has anyone ever worked with Vasil Uzunoglu's Synchronous Oscillators? See US Patents: 4274067, 4335404, 4356456 A couple of other articles about Sync.Osc can be found here: http://www.unusualresearch.com/AppNotes/AppNotes.htm Sync. Osc's are good where you need to lock to a single frequency. -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Gate propagation delay jitter
I await Bob Paddock's circuit with bated breath. Found a copy of the circuit I had in mind on line, look at figure #25: http://www.linear-tech.co.jp/pc/downloadDocument.do?navId=H0,C1,C1155,C1001,C1158,P1442,D1594 That circuit has a few problems, it is also based on ten year old parts. One of the problems that is easy to fix is related to the bad divider thread. In a multi-input gate, especially Schmitt Trigger ones, never connect the inputs together. There is the obvious problem of more capacitance on the input, but there is the more subtle difference in switching time of the inputs within the same gate adding. Connect the unneeded inputs to the appropriate logic levels. Make a current source out of a current feed back op-amp that has a high slew rate for charging the cap, feeding a fast trackhold. The A/D itself does not have to be all that fast, as long as there is little drupe before the sampling cap starts to discharge. Also check out: High-Speed Time-Domain Measurements—Practical Tips for Improvement http://www.analog.com/library/analogDialogue/archives/41-03/time_domain.html -- http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Gate propagation delay jitter
On Monday 09 April 2007 01:16, Dr Bruce Griffiths wrote: The attached table of logic gate propagation delay jitter should prove somewhat challenging to verify with a time interval counter or similar device. Then don't use them. Does anyone have any other practical method of measuring such small jitter? Set up a current source to charge a cap, samplehold, and bow correction, then measure the delta between two points. Somethings are still better to be done in the analog domain. I'll put a circuit on my web site when I get back in town later in the week. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] GPS disciplined oscillators - how not to do it.
On Tuesday 03 April 2007 21:48, Dr Bruce Griffiths wrote: An Australian Electronics magazine recently published a circuit for a GPS disciplined crystal oscillator. This particular implementation is the worst I've ever seen. What would you consider the best you have ever seen? -- http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Ultra low phase noise floor measuremen t system forRF devices.
On Sunday 01 April 2007 11:30, Chuck Harris wrote: Metric vs. English has nothing to do with making things easier, but rather has everything to do with which arbitrary constants you prefer. Here is a question that has nagged me for years, but first the background: When I was in school getting my degree, I had a Physics teacher that gave all of his lectures in the Metric System. The book covered nothing but the Metric System. All of the tests he gave where in the *English* system! Conversions where never mentioned, *anyplace*. Everyone failed the first test. [This kind of #)$*#$* in schools, is the kind of thing that makes be believe in Home Schooling.] The one good thing to come out of that (?), is everyone in class learned to paying attention to the 'Units'. In the English System the unit of Weight is the Pound. The unit of Mass is the Slug. In the Metric System the unit of Weight is the Newton. The unit of Mass is the (Kilo)Gram. So why does this box of cereal (first thing at hand with label) say 10 Oz (284g). All of these dual unit labels are comparing weight vs mass. Why? I'm sure virtually all Americans think the Gram is a unit of weight. -- http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
