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A little metal project
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A little metal project
NEAT !!!! On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ |
A little metal project
Don Foreman wrote:
http://members.goldengate.net/dforeman/yellowlight/ Extremely cool, Don. --Winston -- Congratulations Robert Piccinini and Steven A. Burd, WalMart Publicists of the Year! |
A little metal project
On Jan 6, 11:22*pm, Don Foreman wrote:
http://members.goldengate.net/dforeman/yellowlight/ Schweet. Dave |
A little metal project
On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman
wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! What do you use for a power supply? |
A little metal project
On Jan 6, 8:22*pm, Don Foreman wrote:
http://members.goldengate.net/dforeman/yellowlight/ Nicely done! Paul |
A little metal project
On Thu, 07 Jan 2010 10:28:57 -0500, Spehro Pefhany
wrote: On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! What do you use for a power supply? That's my next project. G It needs to be a 700 mA current source with load voltage circa 3 volts or so. Previous version was 350 mA so an LM317 and sense resistor epoxied on the top of a wallwart sufficed. Might work here too if I can find a 4.5 or 6 volt 700mA wallwart. Else, maybe a little switcher. |
A little metal project
Good job - as per the usual Foreman standard.
Bob Swinney "Don Foreman" wrote in message ... http://members.goldengate.net/dforeman/yellowlight/ |
A little metal project
On Thu, 07 Jan 2010 12:30:23 -0600, Don Foreman
wrote: On Thu, 07 Jan 2010 10:28:57 -0500, Spehro Pefhany wrote: On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! What do you use for a power supply? That's my next project. G It needs to be a 700 mA current source with load voltage circa 3 volts or so. Previous version was 350 mA so an LM317 and sense resistor epoxied on the top of a wallwart sufficed. Might work here too if I can find a 4.5 or 6 volt 700mA wallwart. Else, maybe a little switcher. It's cheating a bit, but have you seen these? http://www.leddynamics.com/LuxDrive/...1-BuckPlus.pdf $15.99 in one-off for the 700mA version and another $1 for the one with dimming. |
A little metal project
On Jan 6, 10:22*pm, Don Foreman wrote:
http://members.goldengate.net/dforeman/yellowlight/ Looks like it might be a useful idea for making a small camera mount too. |
A little metal project
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A little metal project
On Thu, 07 Jan 2010 12:30:23 -0600, the infamous Don Foreman
scrawled the following: On Thu, 07 Jan 2010 10:28:57 -0500, Spehro Pefhany wrote: On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! I'll echo that one, too. What do you use for a power supply? That's my next project. G It needs to be a 700 mA current source with load voltage circa 3 volts or so. Previous version was 350 mA so an LM317 and sense resistor epoxied on the top of a wallwart sufficed. Might work here too if I can find a 4.5 or 6 volt 700mA wallwart. Else, maybe a little switcher. Remember to spray paint this one poorly. It'll take the shine off it so it doesn't disappear like the last one. You know how thieves are when it comes to shiny baubles. -- We rightly care about the environment. But our neurotic obsession with carbon betrays an inability to distinguish between pollution and the stuff of life itself. --Bret Stephens, WSJ 1/5/10 |
A little metal project
Don Foreman wrote:
http://members.goldengate.net/dforeman/yellowlight/ Very neat little job . Found this one on alink on Utubeto site regarding a magazine called Make. http://www.flickr.com/photos/lishnes.../in/pool-make/ -- Kevin (Bluey) "I'm not young enough to know everything." |
A little metal project
On Thu, 07 Jan 2010 14:35:21 -0500, Spehro Pefhany
wrote: On Thu, 07 Jan 2010 12:30:23 -0600, Don Foreman wrote: On Thu, 07 Jan 2010 10:28:57 -0500, Spehro Pefhany wrote: On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! What do you use for a power supply? That's my next project. G It needs to be a 700 mA current source with load voltage circa 3 volts or so. Previous version was 350 mA so an LM317 and sense resistor epoxied on the top of a wallwart sufficed. Might work here too if I can find a 4.5 or 6 volt 700mA wallwart. Else, maybe a little switcher. It's cheating a bit, but have you seen these? http://www.leddynamics.com/LuxDrive/...1-BuckPlus.pdf $15.99 in one-off for the 700mA version and another $1 for the one with dimming. After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. I need to go to a switcher because of my available xfmr choices. I have several that have the necessary 2.4VA ratings but they're all rated for more voltage and less current than I need. A switcher solves that nicely. Current ripple will probably be about 200 mA P-P, which doesn't matter at all in this app. The biggest inefficiency is in the current sense resistor where maybe a quarter watt becomes heat, oh dear! Uh no, by far the dominant inefficiency and heat generator will be the xfmr. |
A little metal project
On Fri, 08 Jan 2010 23:45:09 -0600, the renowned Don Foreman
wrote: On Thu, 07 Jan 2010 14:35:21 -0500, Spehro Pefhany wrote: On Thu, 07 Jan 2010 12:30:23 -0600, Don Foreman wrote: On Thu, 07 Jan 2010 10:28:57 -0500, Spehro Pefhany wrote: On Wed, 06 Jan 2010 22:22:56 -0600, Don Foreman wrote: http://members.goldengate.net/dforeman/yellowlight/ Velly nice! What do you use for a power supply? That's my next project. G It needs to be a 700 mA current source with load voltage circa 3 volts or so. Previous version was 350 mA so an LM317 and sense resistor epoxied on the top of a wallwart sufficed. Might work here too if I can find a 4.5 or 6 volt 700mA wallwart. Else, maybe a little switcher. It's cheating a bit, but have you seen these? http://www.leddynamics.com/LuxDrive/...1-BuckPlus.pdf $15.99 in one-off for the 700mA version and another $1 for the one with dimming. After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. I need to go to a switcher because of my available xfmr choices. I have several that have the necessary 2.4VA ratings but they're all rated for more voltage and less current than I need. A switcher solves that nicely. Current ripple will probably be about 200 mA P-P, which doesn't matter at all in this app. The biggest inefficiency is in the current sense resistor where maybe a quarter watt becomes heat, oh dear! Uh no, by far the dominant inefficiency and heat generator will be the xfmr. That should work nicely. The ripple will give you more heating than otherwise, of course. Usual LED mfr recommendations are 5-20% maximum current ripple. Here's another "canned" solution: http://www.sure-electronics.net/DC,I...s/LE-LL209.pdf At the other end of the scale, do you have any of those 5V switchers laying around? Last I looked, a surplus place near me has a big stack of brand new compact 5V wall plug switchers for about $2-3. Inside is a flyback converter using a UC3843 (clone), with the usual TL431 2.5V reference/optoisolator feedback, so changing the resistor ratio on the TL431 would allow the voltage to be lowered to something like 3.5V. (I gently crack the ultrasonic case welding open with a vise, then they can be glued shut again with epoxy- usually you can't tell they were ever opened without looking very closely.). Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
A little metal project
On Sat, 09 Jan 2010 10:04:25 -0500, Spehro Pefhany
wrote: On Fri, 08 Jan 2010 23:45:09 -0600, the renowned Don Foreman wrote: SNIP SNIP SNIP After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. I need to go to a switcher because of my available xfmr choices. I have several that have the necessary 2.4VA ratings but they're all rated for more voltage and less current than I need. A switcher solves that nicely. Current ripple will probably be about 200 mA P-P, which doesn't matter at all in this app. The biggest inefficiency is in the current sense resistor where maybe a quarter watt becomes heat, oh dear! Uh no, by far the dominant inefficiency and heat generator will be the xfmr. That should work nicely. The ripple will give you more heating than otherwise, of course. Usual LED mfr recommendations are 5-20% maximum current ripple. Here's another "canned" solution: http://www.sure-electronics.net/DC,I...s/LE-LL209.pdf At the other end of the scale, do you have any of those 5V switchers laying around? Last I looked, a surplus place near me has a big stack of brand new compact 5V wall plug switchers for about $2-3. Inside is a flyback converter using a UC3843 (clone), with the usual TL431 2.5V reference/optoisolator feedback, so changing the resistor ratio on the TL431 would allow the voltage to be lowered to something like 3.5V. (I gently crack the ultrasonic case welding open with a vise, then they can be glued shut again with epoxy- usually you can't tell they were ever opened without looking very closely.). Best regards, Spehro Pefhany Hey you two, I know there's lots of OT stuff here on RCM, but it's ALMOST ALWAYS in ENGLISH !!! So how about sticking with the common language in this thread!?!?!? Heh heh heh. Brian Lawson, Bothwell, Ontario. ps....actually, I enjoyed going through my catalogues trying to figure out what you were doing!! |
A little metal project
On Jan 9, 3:03*pm, Brian Lawson wrote:
On Sat, 09 Jan 2010 10:04:25 -0500, Spehro Pefhany On Fri, 08 Jan 2010 23:45:09 -0600, the renowned Don Foreman ... hysteretic switching *current regulator ...220 uH inductor ...MCP6022 opamp, *MOSFET, Schottky diode, sense resistor and voltage reference. ... a flyback converter using a UC3843 (clone), with the usual TL431 2..5V reference/optoisolator feedback, so changing the resistor ratio on the TL431 would allow the voltage to be lowered to something like 3.5V. ... Spehro Pefhany Hey you two, I know there's lots of OT stuff here on RCM, but it's ALMOST ALWAYS in ENGLISH !!! * So how about sticking with the common language in this thread!?!?!? Heh heh heh. Brian Lawson, Bothwell, Ontario. I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. jsw |
A little metal project
On Sat, 09 Jan 2010 15:03:33 -0500, Brian Lawson
wrote: On Sat, 09 Jan 2010 10:04:25 -0500, Spehro Pefhany wrote: On Fri, 08 Jan 2010 23:45:09 -0600, the renowned Don Foreman wrote: SNIP SNIP SNIP After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. I need to go to a switcher because of my available xfmr choices. I have several that have the necessary 2.4VA ratings but they're all rated for more voltage and less current than I need. A switcher solves that nicely. Current ripple will probably be about 200 mA P-P, which doesn't matter at all in this app. The biggest inefficiency is in the current sense resistor where maybe a quarter watt becomes heat, oh dear! Uh no, by far the dominant inefficiency and heat generator will be the xfmr. That should work nicely. The ripple will give you more heating than otherwise, of course. Usual LED mfr recommendations are 5-20% maximum current ripple. Here's another "canned" solution: http://www.sure-electronics.net/DC,I...s/LE-LL209.pdf At the other end of the scale, do you have any of those 5V switchers laying around? Last I looked, a surplus place near me has a big stack of brand new compact 5V wall plug switchers for about $2-3. Inside is a flyback converter using a UC3843 (clone), with the usual TL431 2.5V reference/optoisolator feedback, so changing the resistor ratio on the TL431 would allow the voltage to be lowered to something like 3.5V. (I gently crack the ultrasonic case welding open with a vise, then they can be glued shut again with epoxy- usually you can't tell they were ever opened without looking very closely.). Best regards, Spehro Pefhany Hey you two, I know there's lots of OT stuff here on RCM, but it's ALMOST ALWAYS in ENGLISH !!! So how about sticking with the common language in this thread!?!?!? Heh heh heh. Brian Lawson, Bothwell, Ontario. Well, ya connect the libtard to the neocon via the winger ... nevermind. |
A little metal project
On Fri, 08 Jan 2010 23:45:09 -0600, Don Foreman
wrote: After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. Where did all those nice unijunction transistors of yesteryear go :-( Mark Rand RTFM |
A little metal project
Jim Wilkins wrote: I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. It's more fun when you toss in the other MEs (Manufacturing Engineering) to the mix. Each group thinks they are the only ones who matter. :( -- Greed is the root of all eBay. |
A little metal project
Jim Wilkins wrote:
(...) I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. A sales guy I knew, frustrated with the noises made by electronic engineers dubbed their language "di double - E feedback". --Winston |
A little metal project
Mark Rand wrote:
On Fri, 08 Jan 2010 23:45:09 -0600, Don Foreman wrote: After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. Where did all those nice unijunction transistors of yesteryear go :-( Check two bins to the right of the Tunnel Diodes. --Winston -- Congratulations Robert Piccinini and Steven A. Burd, WalMart Publicists of the Year! |
A little metal project
On Jan 9, 8:46*pm, "Michael A. Terrell"
wrote: Jim Wilkins wrote: I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. * *It's more fun when you toss in the other MEs (Manufacturing Engineering) to the mix. Each group thinks they are the only ones who matter. :( I've only worked directly for one Manufacturing Engineer and he was happy to let me design circuits and otherwise do as I pleased. But yes, they can all become very defensive and territorial. Sometimes after the hardware is functional I work for the software group as a test engineer. Another can of worms opened. jsw |
A little metal project
"Mark Rand" wrote in message ... On Fri, 08 Jan 2010 23:45:09 -0600, Don Foreman wrote: After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. Where did all those nice unijunction transistors of yesteryear go :-( Mark Rand RTFM Probably a few up in the attic. |
A little metal project
On Sun, 10 Jan 2010 00:48:00 +0000, Mark Rand
wrote: On Fri, 08 Jan 2010 23:45:09 -0600, Don Foreman wrote: After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. Where did all those nice unijunction transistors of yesteryear go :-( Mark Rand RTFM They're still available. 48 cents at Digi-Key http://tinyurl.com/y86xeer In the UK, Farnell's has 'em: http://tinyurl.com/y9gk9fx |
A little metal project
On Sat, 09 Jan 2010 18:33:30 -0800, Winston
wrote: Jim Wilkins wrote: (...) I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. A sales guy I knew, frustrated with the noises made by electronic engineers dubbed their language "di double - E feedback". --Winston Whereas, a sales guy or politician can speak for 20 minutes without saying a damned thing so it doesn't matter whether or not their utterance is comprehensible. |
A little metal project
On Sat, 09 Jan 2010 10:04:25 -0500, Spehro Pefhany
wrote: At the other end of the scale, do you have any of those 5V switchers laying around? Last I looked, a surplus place near me has a big stack of brand new compact 5V wall plug switchers for about $2-3. The surplus store near me has some but they want more like 12 bux for them. Arrgghh, highway robbery! I found a little 2.4VA 8VRMS 60-Hz xfmr in my goodiebox that should work nicely. |
A little metal project
On 1/9/2010 11:27 PM, Don Foreman wrote:
I found a little 2.4VA 8VRMS 60-Hz xfmr in my goodiebox that should work nicely. I used to use a lot of the LT "simple switcher" eval boards. Cheap (at the time they were 8 bucks), small (1" X 2") and easy to mod. Kevin Gallimore |
A little metal project
On Sat, 09 Jan 2010 22:16:16 -0600, the renowned Don Foreman
wrote: On Sun, 10 Jan 2010 00:48:00 +0000, Mark Rand wrote: On Fri, 08 Jan 2010 23:45:09 -0600, Don Foreman wrote: After thinking about that some today, I'm leaning toward a dirt-simple hysteretic switching current regulator comprised of a 220 uH inductor (35 cents at AxMan), MCP6022 opamp, MOSFET, Schottky diode, sense resistor and voltage reference. Maybe 2 more resistors to get a 0.5 volt ref from a 1.23V bandgap device. All bench stock. I sometimes build such simple circuits "in air", no circuit board. Just solder the various parts together with perhaps a bit of hookup wire and then pot the lot in epoxy on top of the wallwart xfmr that supplies the low-voltage line-isolated DC. Where did all those nice unijunction transistors of yesteryear go :-( Mark Rand RTFM They're still available. 48 cents at Digi-Key http://tinyurl.com/y86xeer In the UK, Farnell's has 'em: http://tinyurl.com/y9gk9fx And they are cheap. But the 2N6027/8 are PUTs, a kind of SCR-like 4-layer thyristor device, not real unijunctions (eg. 2N2646). But Newark still has the 2N2646 : http://www.newark.com/jsp/search/pro...FC-GB100000001 http://www.newark.com/multicomp/2n26... iscretes_None I miss LASCRs (light activated SCRs), SBS (Silicon bilateral switches), tunnel diodes, germanium transistors, clean air, tuna, Taiwan. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
A little metal project
On 2010-01-10, Spehro Pefhany wrote:
[ ... ] I miss LASCRs (light activated SCRs), SBS (Silicon bilateral switches), tunnel diodes, germanium transistors, clean air, tuna, Taiwan. How many here have ever heard of a "binistor"? A 4-pin bistable device which apparently never took off in the market. It was a four-layer device (like a SCR -- except that it had another pin to allow turning it off. IIRC, Transitron gave it the designation 3N21. I could look it up in the old Transitron data book -- but I don't know where that is at the moment. :-) Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
A little metal project
On 10 Jan 2010 23:23:50 GMT, "DoN. Nichols"
wrote: 3N21 Hey DoN, http://www.americanmicrosemi.com/information/spec/?ss_pn=3N21 |
A little metal project
On 1/10/2010 6:23 PM, DoN. Nichols wrote:
How many here have ever heard of a "binistor"? A 4-pin bistable device which apparently never took off in the market. It was a four-layer device (like a SCR -- except that it had another pin to allow turning it off. IIRC, Transitron gave it the designation 3N21. I could look it up in the old Transitron data book -- but I don't know where that is at the moment. :-) I knew them as SCSs (silicon controlled switch). Kevin Gallimore |
A little metal project
DoN. Nichols wrote:
On 2010-01-10, Spehro Pefhany wrote: [ ... ] I miss LASCRs (light activated SCRs), SBS (Silicon bilateral switches), tunnel diodes, germanium transistors, clean air, tuna, Taiwan. How many here have ever heard of a "binistor"? A 4-pin bistable device which apparently never took off in the market. It was a four-layer device (like a SCR -- except that it had another pin to allow turning it off. IIRC, Transitron gave it the designation 3N21. I could look it up in the old Transitron data book -- but I don't know where that is at the moment. :-) Enjoy, DoN. Sounds like a GTO: http://en.wikipedia.org/wiki/Gate_turn-off_thyristor http://www.youtube.com/watch?v=o_FSicQWimU --Winston -- You taught me tolerance, kindness, generosity and optimism. By example, yes? |
A little metal project
On 2010-01-10, Brian Lawson wrote:
On 10 Jan 2010 23:23:50 GMT, "DoN. Nichols" wrote: 3N21 Hey DoN, http://www.americanmicrosemi.com/information/spec/?ss_pn=3N21 O.K. Germanium means that I have given the wrong part number. It was a silicon device. I wonder what those 3N devices were, how they earned the leading 3 instead of 2. Transitron used it as a count of junctions (e.g. one less than the number of leads. Thanks, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
A little metal project
On Sun, 10 Jan 2010 16:17:37 -0800, Winston
wrote: DoN. Nichols wrote: On 2010-01-10, Spehro Pefhany wrote: [ ... ] I miss LASCRs (light activated SCRs), SBS (Silicon bilateral switches), tunnel diodes, germanium transistors, clean air, tuna, Taiwan. How many here have ever heard of a "binistor"? A 4-pin bistable device which apparently never took off in the market. It was a four-layer device (like a SCR -- except that it had another pin to allow turning it off. IIRC, Transitron gave it the designation 3N21. I could look it up in the old Transitron data book -- but I don't know where that is at the moment. :-) Enjoy, DoN. Sounds like a GTO: http://en.wikipedia.org/wiki/Gate_turn-off_thyristor http://www.youtube.com/watch?v=o_FSicQWimU --Winston Made by Pontiac? |
A little metal project
Don Foreman wrote:
On Sun, 10 Jan 2010 16:17:37 -0800, Winston wrote: (...) Sounds like a GTO: http://en.wikipedia.org/wiki/Gate_turn-off_thyristor http://www.youtube.com/watch?v=o_FSicQWimU --Winston Made by Pontiac? First one, no. Second one, yes. --Winston -- You taught me tolerance, kindness, generosity and optimism. By example, yes? |
A little metal project
In article ,
"DoN. Nichols" wrote: On 2010-01-10, Brian Lawson wrote: On 10 Jan 2010 23:23:50 GMT, "DoN. Nichols" wrote: 3N21 Hey DoN, http://www.americanmicrosemi.com/information/spec/?ss_pn=3N21 O.K. Germanium means that I have given the wrong part number. It was a silicon device. I wonder what those 3N devices were, how they earned the leading 3 instead of 2. Transitron used it as a count of junctions (e.g. one less than the number of leads. The xNyy pattern is from a JAN standard, if I recall. I think that the x is one less than the number of terminals, the then assumption being that one must have at least two terminals. I don't think that the number of junctions was considered, the intent being to treat the device as a black box. I would have guessed that 3N21 was an optocoupler, or a SCR with all four layers connected. However, it seems to be an obsolete transistor type made by Sylvania and Western Electric: http://homepages.nildram.co.uk/~wylie/wanted.htm. However, it turns out to be a Germanium switching transistor: http://www.datasheetarchive.com/3N21-datasheet.html. Joe Gwinn |
A little metal project
Don Foreman wrote: On Sat, 09 Jan 2010 10:04:25 -0500, Spehro Pefhany wrote: At the other end of the scale, do you have any of those 5V switchers laying around? Last I looked, a surplus place near me has a big stack of brand new compact 5V wall plug switchers for about $2-3. The surplus store near me has some but they want more like 12 bux for them. Arrgghh, highway robbery! I found a little 2.4VA 8VRMS 60-Hz xfmr in my goodiebox that should work nicely. http://www.mpja.com/powersupply.asp usually has some good deals. -- Greed is the root of all eBay. |
A little metal project
Winston wrote: Jim Wilkins wrote: (...) I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. A sales guy I knew, frustrated with the noises made by electronic engineers dubbed their language "di double - E feedback". That is the kind of salesman no one wants to deal with, if their IQ is over 70. The last electronics 'salesman' I worked with would visit both engineering and production test to see what was going on, and had started with the company as a tech. If he didn't know the answer to a customer's question, he knew who to call to get the right information. Your 'sales guy' should have gone back to selling used cars, or to putting lids on drinks at McDonalds. -- Greed is the root of all eBay. |
A little metal project
Jim Wilkins wrote: On Jan 9, 8:46 pm, "Michael A. Terrell" wrote: Jim Wilkins wrote: I mentioned earlier working for both MEs and EEs. They don't understand each others' secret language and aren't always too happy that I do. It's more fun when you toss in the other MEs (Manufacturing Engineering) to the mix. Each group thinks they are the only ones who matter. :( I've only worked directly for one Manufacturing Engineer and he was happy to let me design circuits and otherwise do as I pleased. But yes, they can all become very defensive and territorial. Sometimes after the hardware is functional I work for the software group as a test engineer. Another can of worms opened. I worked for an 'Engineering to order' company on products from 12 year old designs to cutting edge. All three departments didn't want to budge, fearing they would be giving up something. As a production test tech, I could stop the shipment of anything that didn't pass the tests. or was too close to the edge on all parameters. A few times of almost missing shipment dates soon had them paying attention. The result was design changes to make testing easier and with better repeatability. New & modified test fixtures, and test software. Better test procedures, including rewriting some written by a Hispanic EE and translated into very ambiguous English. One EE had designed and built the only automated test fixture in the plant, but he totally screwed up the software. He went ballistic when I not only rewrote the software, but added more tests and some diagnostics. My boss had a fit when I added two sound effects to the software. One was a low pitched fog horn whenever the software detected a problem. The other sounded like winning an early video game when the board passed. :) -- Greed is the root of all eBay. |
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