Re: [time-nuts] surface mount (was PICTIC II Parts from Mouser)
Bob, Thank you for the video Now all we need is a robot and software to filter the jitter from my hands. Maybe a little less expensive than the da Vinci robot. http://www.davincisurgery.com/ Stanley - Original Message From: Bob Bownes bow...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, July 19, 2010 11:09:50 PM Subject: Re: [time-nuts] surface mount (was PICTIC II Parts from Mouser) A few short videos shot with the camera/usb video capture setup I mentioned earlier: http://www.fastbobs.com/bob/radio/video1.mpg Video 1 - Black White inspection of a prototype power sensor. Low magnification http://www.fastbobs.com/bob/radio/video2.mpg Video 2 - Colour inspection of same sensor. Same magnification. About 2-3x http://www.fastbobs.com/bob/radio/video3.mpg Video 3 - Longer version of #2. Note lighting changes in 2nd half. http://www.fastbobs.com/bob/radio/video4.mpg Video 4 - Short, color, higher magnification http://www.fastbobs.com/bob/radio/video5.mpg Video 5 - Longest, highest magnification. Same probe as earlier shots. Note lighting changes as the light source is moved around showing shadows. On Mon, Jul 19, 2010 at 9:22 PM, Robert J Marinelli b...@stanford.edu wrote: Hi Richard, Yes, used to feel that way - until acquiring a surplus dissecting (stereo) microscope, now I actually *prefer* surface mount. Much easier to move parts around, it's easy to apply paste solder entire boards in a $50 toaster oven, and access to all the latest parts. Hard to believe, but really is easier once you can clearly see. For some nice tuturials, see the sparkfun website, also the schmartboard website. Also, when I lay out surface mount boards, they tend to be smaller overall, and so a bit lower cost. Please do try with a low cost stereo microscope - it changes everything :) -Bob p.s. Finger size is no issue - tweezers work nicely. Oh and surface mount resistors caps are unbelievably low cost in cut tape, and super easy to handle that way. Much better than loose parts IMO. On Jul 19, 2010, at 4:59 PM, Richard H McCorkle wrote: The TS272CN is an acceptable substitute for the TS272ACN in the PICTIC II but as noted has a higher input offset voltage. This can be compensated for in the second stage by adjustment of the offset trimmer. I selected premium parts for temperature stability in the application. Sorry the manufacturers are making human compatible devices obsolete and only carrying over surface mount devices as they go Pb free for the EU market. Makes it difficult to keep up with what's available and harder for amateurs with fat fingers and poor eyesight like myself to build simple projects! Richard Here we go again! The TS272ACN has just gone 'non-stocked' at Mouser. Will the TS272CN degrade the performance? It looks like the difference between the two is the TS272CN has a higher input offset voltage. Ed ___ 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 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 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 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 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] surface mount (was PICTIC II Parts from Mouser)
Stanley, Your brain will do an excellent job of translating your finger motion to the micro motions necessary to move surface mount parts around with tweezers. Barring disease, the usual solution to finger jitter is to keep tweezers pressure light, and lay off the coffee. Even if you do jitter a bit, there are many tricks you can use to keep it to a minimum. I use the little finger on my tweezers hand as a balance point for my hand. Just the act of having it touch the stage, or board removes all of the jitter. -Chuck Harris Stanley Reynolds wrote: Bob, Thank you for the video Now all we need is a robot and software to filter the jitter from my hands. Maybe a little less expensive than the da Vinci robot. http://www.davincisurgery.com/ Stanley ___ 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] surface mount (was PICTIC II Parts from Mouser)
On 20 July 2010 18:51, Chuck Harris cfhar...@erols.com wrote: ...I use the little finger on my tweezers hand as a balance point for my hand. Just the act of having it touch the stage, or board removes all of the jitter. If only our 1PPS signals had a little finger that could rest somewhere :-) Peter ___ 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] surface mount (was PICTIC II Parts from Mouser)
You'll probably also find that your fine motor control improves a bunch when you can actually *see* what you are doing in 3D. I got a stereo microscope a year or two ago, and I'm amazed at how finely I can control the tip of a pair of tweezers or a knife point or soldering iron under the microscope. It works much better than trying to do the same thing with a one-eyed magnifier like a loupe, partly because a microscope gives you more working distance, but mostly because of the full 3D view of what you're doing. My first stereo microscope was a surplus AO 40 that cost $100, so being able to see what you're doing doesn't have to be expensive. Dave On Tue, Jul 20, 2010 at 10:51 AM, Chuck Harris cfhar...@erols.com wrote: Stanley, Your brain will do an excellent job of translating your finger motion to the micro motions necessary to move surface mount parts around with tweezers. Barring disease, the usual solution to finger jitter is to keep tweezers pressure light, and lay off the coffee. Even if you do jitter a bit, there are many tricks you can use to keep it to a minimum. I use the little finger on my tweezers hand as a balance point for my hand. Just the act of having it touch the stage, or board removes all of the jitter. ___ 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] surface mount (was PICTIC II Parts from Mouser)
It's amazing what one can do by hand. In the 1970s I worked in an electrophysiology lab where we put glass microelectrodes into rat neurons. The microelectrodes were made in the lab by heating 1 mm diameter glass tubing to an orange heat and pulling abruptly. (This was done in a simple machine.) The tube necked down to a very sharp point. Too sharp - needed more tip area to allow for the 3 molar potassium chloride solution within to make adequate electrical contact with whatever was being probed. The tip was far smaller than a wavelength of light. The tip image degenerates into an interference pattern when looked at with an optical microscope. Solution? Put the tube on the stage of a 2000x microscope with the tip in view. Take an ordinary glass rod in one hand and manually bring the tip into view through the microscope. Gently tap the tip with the rod, breaking the tip back until an adequate opening is achieved. How is the gently tap achieved? One merely thinks of moving the rod. There is enough leakage from intent to action that the rod will move enough to do the job, this being a few wavelengths of light. All this is done freehand, although the wrist must be on a rest of some kind. It turns out that almost everybody can do this, and I was able to do it on the first try. To my considerable surprise. Joe From: David Martindale dave.martind...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: 07/20/2010 02:16 PM Subject: Re: [time-nuts] surface mount (was PICTIC II Parts from Mouser) Sent by: time-nuts-boun...@febo.com You'll probably also find that your fine motor control improves a bunch when you can actually *see* what you are doing in 3D. I got a stereo microscope a year or two ago, and I'm amazed at how finely I can control the tip of a pair of tweezers or a knife point or soldering iron under the microscope. It works much better than trying to do the same thing with a one-eyed magnifier like a loupe, partly because a microscope gives you more working distance, but mostly because of the full 3D view of what you're doing. My first stereo microscope was a surplus AO 40 that cost $100, so being able to see what you're doing doesn't have to be expensive. Dave On Tue, Jul 20, 2010 at 10:51 AM, Chuck Harris cfhar...@erols.com wrote: Stanley, Your brain will do an excellent job of translating your finger motion to the micro motions necessary to move surface mount parts around with tweezers. Barring disease, the usual solution to finger jitter is to keep tweezers pressure light, and lay off the coffee. Even if you do jitter a bit, there are many tricks you can use to keep it to a minimum. I use the little finger on my tweezers hand as a balance point for my hand. Just the act of having it touch the stage, or board removes all of the jitter. ___ 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 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] surface mount (was PICTIC II Parts from Mouser)
Hi Richard, Yes, used to feel that way - until acquiring a surplus dissecting (stereo) microscope, now I actually *prefer* surface mount. Much easier to move parts around, it's easy to apply paste solder entire boards in a $50 toaster oven, and access to all the latest parts. Hard to believe, but really is easier once you can clearly see. For some nice tuturials, see the sparkfun website, also the schmartboard website. Also, when I lay out surface mount boards, they tend to be smaller overall, and so a bit lower cost. Please do try with a low cost stereo microscope - it changes everything :) -Bob p.s. Finger size is no issue - tweezers work nicely. Oh and surface mount resistors caps are unbelievably low cost in cut tape, and super easy to handle that way. Much better than loose parts IMO. On Jul 19, 2010, at 4:59 PM, Richard H McCorkle wrote: The TS272CN is an acceptable substitute for the TS272ACN in the PICTIC II but as noted has a higher input offset voltage. This can be compensated for in the second stage by adjustment of the offset trimmer. I selected premium parts for temperature stability in the application. Sorry the manufacturers are making human compatible devices obsolete and only carrying over surface mount devices as they go Pb free for the EU market. Makes it difficult to keep up with what's available and harder for amateurs with fat fingers and poor eyesight like myself to build simple projects! Richard Here we go again! The TS272ACN has just gone 'non-stocked' at Mouser. Will the TS272CN degrade the performance? It looks like the difference between the two is the TS272CN has a higher input offset voltage. Ed ___ 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 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 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] surface mount (was PICTIC II Parts from Mouser)
Not to mention not having to drill holes anymore. I built a 15Ghz prescaler over the weekend. Total time from concept to completed (and operational!) prototype was 2 hours. No muss, no fuss, just design the circuit, print out the toner transfer, paste it onto the board, etch, apply paste parts, drop into the toaster, er, reflow oven, pull it out, inspect and turn it on. You don't even need to go as far as the microscope (though they really do make the job easier). A simple $10 set of magnifying eye pieces or a 5x magnifying glass lamp ($30 @ Harbor Freight) does a great job. Am alternative is a webcam that will focus up close. I hooked up an old TV camera with a macro lens (ebay, $5) to a video capture USB dongle (ebay again, $15) and put it on an old retort stand. I can look at it on the screen on the workbench and even do video capture of the board. Pretty much the ultimate in cheap magnification. I covered some of this in a presentation at the NEWS conference last winter. http://www.fastbobs.com/bob/radio/power_meter.ppt Bob On Mon, Jul 19, 2010 at 9:22 PM, Robert J Marinelli b...@stanford.edu wrote: Hi Richard, Yes, used to feel that way - until acquiring a surplus dissecting (stereo) microscope, now I actually *prefer* surface mount. Much easier to move parts around, it's easy to apply paste solder entire boards in a $50 toaster oven, and access to all the latest parts. Hard to believe, but really is easier once you can clearly see. For some nice tuturials, see the sparkfun website, also the schmartboard website. Also, when I lay out surface mount boards, they tend to be smaller overall, and so a bit lower cost. Please do try with a low cost stereo microscope - it changes everything :) -Bob p.s. Finger size is no issue - tweezers work nicely. Oh and surface mount resistors caps are unbelievably low cost in cut tape, and super easy to handle that way. Much better than loose parts IMO. On Jul 19, 2010, at 4:59 PM, Richard H McCorkle wrote: The TS272CN is an acceptable substitute for the TS272ACN in the PICTIC II but as noted has a higher input offset voltage. This can be compensated for in the second stage by adjustment of the offset trimmer. I selected premium parts for temperature stability in the application. Sorry the manufacturers are making human compatible devices obsolete and only carrying over surface mount devices as they go Pb free for the EU market. Makes it difficult to keep up with what's available and harder for amateurs with fat fingers and poor eyesight like myself to build simple projects! Richard Here we go again! The TS272ACN has just gone 'non-stocked' at Mouser. Will the TS272CN degrade the performance? It looks like the difference between the two is the TS272CN has a higher input offset voltage. Ed ___ 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 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 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 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] surface mount (was PICTIC II Parts from Mouser)
A few short videos shot with the camera/usb video capture setup I mentioned earlier: http://www.fastbobs.com/bob/radio/video1.mpg Video 1 - Black White inspection of a prototype power sensor. Low magnification http://www.fastbobs.com/bob/radio/video2.mpg Video 2 - Colour inspection of same sensor. Same magnification. About 2-3x http://www.fastbobs.com/bob/radio/video3.mpg Video 3 - Longer version of #2. Note lighting changes in 2nd half. http://www.fastbobs.com/bob/radio/video4.mpg Video 4 - Short, color, higher magnification http://www.fastbobs.com/bob/radio/video5.mpg Video 5 - Longest, highest magnification. Same probe as earlier shots. Note lighting changes as the light source is moved around showing shadows. On Mon, Jul 19, 2010 at 9:22 PM, Robert J Marinelli b...@stanford.edu wrote: Hi Richard, Yes, used to feel that way - until acquiring a surplus dissecting (stereo) microscope, now I actually *prefer* surface mount. Much easier to move parts around, it's easy to apply paste solder entire boards in a $50 toaster oven, and access to all the latest parts. Hard to believe, but really is easier once you can clearly see. For some nice tuturials, see the sparkfun website, also the schmartboard website. Also, when I lay out surface mount boards, they tend to be smaller overall, and so a bit lower cost. Please do try with a low cost stereo microscope - it changes everything :) -Bob p.s. Finger size is no issue - tweezers work nicely. Oh and surface mount resistors caps are unbelievably low cost in cut tape, and super easy to handle that way. Much better than loose parts IMO. On Jul 19, 2010, at 4:59 PM, Richard H McCorkle wrote: The TS272CN is an acceptable substitute for the TS272ACN in the PICTIC II but as noted has a higher input offset voltage. This can be compensated for in the second stage by adjustment of the offset trimmer. I selected premium parts for temperature stability in the application. Sorry the manufacturers are making human compatible devices obsolete and only carrying over surface mount devices as they go Pb free for the EU market. Makes it difficult to keep up with what's available and harder for amateurs with fat fingers and poor eyesight like myself to build simple projects! Richard Here we go again! The TS272ACN has just gone 'non-stocked' at Mouser. Will the TS272CN degrade the performance? It looks like the difference between the two is the TS272CN has a higher input offset voltage. Ed ___ 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 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 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 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.
