"John S" <Sophi.2@invalid.org> wrote in message news:o41crl$d56$3@dont-email.me...> On 12/28/2016 3:50 PM, billbowden wrote: >> "John S" <Sophi.2@invalid.org> wrote in message >> news:o4142f$d56$2@dont-email.me... >>> On 12/27/2016 8:02 PM, billbowden wrote: >>>> I think I have a working modle using just two transistors. The pulse >>>> shape >>>> is not the best, but better than the original magazine circuit. .Total >>>> part >>>> count is 10 verses 12 with the old circuit so I saved 2 parts. And it >>>> triggers on 250mV. Haven't built it yet, I'll wait until I sell one of >>>> the >>>> old ones at Doc's. I sold my original for $25 a couple weeks ago. I >>>> think >>>> I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. >>> >>> Well, your OP indicated you wanted to use one transistor and that the >>> input voltage would be 300mV. So, the specs have changed now? >>> >>> Where can I find the 250mV trigger in the simulation? >>> >>> (Snip LTSpice listing) >>> >> >> The OP just concerned switching the first transistor.I didn't care much >> about the second. The way I tested for 250mV was to disconnect the 4.7u >> capacitor and apply a 250mV sine at 20 hertz directly to the cathode of >> the >> diode, Then look at the collector of the 3904 and it will swing almost >> rail >> to rail (3.2 to .0.15) > > This has become completely ridiculous. >Yes, you're right. An easier way to see the 250mV trigger is to disconnect the 4.7u cap and then just look at the trigger at the cathode of the diode. I'm reading 235mV.
Bipolar transistor bias question
Started by ●December 18, 2016
Reply by ●December 28, 20162016-12-28
Reply by ●December 28, 20162016-12-28
<dagmargoodboat@yahoo.com> wrote in message news:bf8b3efd-e741-43ff-a946-fb10cd48771d@googlegroups.com... On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote:> <dagmargoodboat@yahoo.com> wrote in message > > I think I have a working modle using just two transistors. The pulse shape > is not the best, but better than the original magazine circuit. .Total > part > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of the > old ones at Doc's. I sold my original for $25 a couple weeks ago. I think > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years.<snip LTSpice> That's cute. And power consumption is down below 1mA. Is your coil really 300mH? A nice feature is how easily you can set the output pulse width to minimize power usage. For your amusement, here's a version of your circuit with a MOSFET output. (I injected the simulated coil pick-up voltage slightly differently.) Cheers, James Arthur <snip LTSpice listing> Interesting, and you saved another part. But it doesn't seem to work on a 2 volt battery. I'm figuring a couple AA cells will be close to dead at 1 volt each, so I need the thing to operate on 2 volts.. The coil inductance may be lower at 150mH. I just looked at this air core inductance calculator and plugged in the appriximate values of 150mH and 1/4 inch for both inner coil diameter and length.and wire gauge of #38. It shows 3300 turns and about 300 ohms of resistance, which is about what I have. So, the inductance may be lower at 150mH. The air core calculator is here: http://www.pronine.ca/multind.htm .
Reply by ●December 28, 20162016-12-28
On Wednesday, December 28, 2016 at 7:58:39 PM UTC-5, Bill Bowden wrote:> <dagmargoodboat@yahoo.com> wrote in message > news:bf8b3efd-e741-43ff-a946-fb10cd48771d@googlegroups.com... > On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote: > > <dagmargoodboat@yahoo.com> wrote in message > > > > I think I have a working modle using just two transistors. The pulse shape > > is not the best, but better than the original magazine circuit. .Total > > part > > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of the > > old ones at Doc's. I sold my original for $25 a couple weeks ago. I think > > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. > > <snip LTSpice> > > That's cute. And power consumption is down below 1mA. > Is your coil really 300mH? > > A nice feature is how easily you can set the output pulse width to minimize > power usage. > > For your amusement, here's a version of your circuit with a MOSFET output. > (I injected the simulated coil pick-up voltage slightly differently.) > > > <snip LTSpice listing> > > Interesting, and you saved another part. But it doesn't seem to work on a 2 > volt battery. I'm figuring a couple AA cells will be close to dead at 1 volt > each, so I need the thing to operate on 2 volts..Just tried it--works fine for me @ 1.0 V. But you'll prefer the jellybean BJT's; this was just for fun.> The coil inductance may be lower at 150mH. I just looked at this air core > inductance calculator and plugged in the appriximate values of 150mH and 1/4 > inch for both inner coil diameter and length.and wire gauge of #38. It shows > 3300 turns and about 300 ohms of resistance, which is about what I have. So, > the inductance may be lower at 150mH.The key thing will be whether the new coil gives the pendulum enough of a 'push' to keep 'er going. Then you can tweak the drive pulse width to save power.> The air core calculator is here: > > http://www.pronine.ca/multind.htmCheers, James Arthur
Reply by ●December 28, 20162016-12-28
<dagmargoodboat@yahoo.com> wrote in message news:0377f2d8-b993-4bf2-b54b-833df4c1d824@googlegroups.com...> On Wednesday, December 28, 2016 at 7:58:39 PM UTC-5, Bill Bowden wrote: >> <dagmargoodboat@yahoo.com> wrote in message >> news:bf8b3efd-e741-43ff-a946-fb10cd48771d@googlegroups.com... >> On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote: >> > <dagmargoodboat@yahoo.com> wrote in message >> > >> > I think I have a working modle using just two transistors. The pulse >> > shape >> > is not the best, but better than the original magazine circuit. .Total >> > part >> > count is 10 verses 12 with the old circuit so I saved 2 parts. And it >> > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of >> > the >> > old ones at Doc's. I sold my original for $25 a couple weeks ago. I >> > think >> > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. >> >> <snip LTSpice> >> >> That's cute. And power consumption is down below 1mA. >> Is your coil really 300mH? >> >> A nice feature is how easily you can set the output pulse width to >> minimize >> power usage. >> >> For your amusement, here's a version of your circuit with a MOSFET >> output. >> (I injected the simulated coil pick-up voltage slightly differently.) >> >> >> <snip LTSpice listing> >> >> Interesting, and you saved another part. But it doesn't seem to work on a >> 2 >> volt battery. I'm figuring a couple AA cells will be close to dead at 1 >> volt >> each, so I need the thing to operate on 2 volts.. > > Just tried it--works fine for me @ 1.0 V. But you'll prefer the jellybean > BJT's; this was just for fun. > >> The coil inductance may be lower at 150mH. I just looked at this air core >> inductance calculator and plugged in the appriximate values of 150mH and >> 1/4 >> inch for both inner coil diameter and length.and wire gauge of #38. It >> shows >> 3300 turns and about 300 ohms of resistance, which is about what I have. >> So, >> the inductance may be lower at 150mH. > > The key thing will be whether the new coil gives the pendulum > enough of a 'push' to keep 'er going. Then you can tweak the > drive pulse width to save power. > >> The air core calculator is here: >> >> http://www.pronine.ca/multind.htm > > Cheers, > James ArthurSo,what am I doing wrong? All I changed was V1 to 2 volts and I get an output pulse of 200mV and a width of 1mS. That won't work.
Reply by ●December 29, 20162016-12-29
On 29/12/16 03:00, billbowden wrote:> So,what am I doing wrong? All I changed was V1 to 2 volts and I get an > output pulse of 200mV and a width of 1mS.Confusing time and conductance?
Reply by ●December 29, 20162016-12-29
On Wednesday, December 28, 2016 at 10:00:45 PM UTC-5, Bill Bowden wrote:> <dagmargoodboat@yahoo.com> wrote in message > news:0377f2d8-b993-4bf2-b54b-833df4c1d824@googlegroups.com... > > On Wednesday, December 28, 2016 at 7:58:39 PM UTC-5, Bill Bowden wrote: > >> <dagmargoodboat@yahoo.com> wrote in message > >> news:bf8b3efd-e741-43ff-a946-fb10cd48771d@googlegroups.com... > >> On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote: > >> > <dagmargoodboat@yahoo.com> wrote in message > >> > > >> > I think I have a working modle using just two transistors. The pulse > >> > shape > >> > is not the best, but better than the original magazine circuit. .Total > >> > part > >> > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > >> > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of > >> > the > >> > old ones at Doc's. I sold my original for $25 a couple weeks ago. I > >> > think > >> > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. > >> > >> <snip LTSpice> > >> > >> That's cute. And power consumption is down below 1mA. > >> Is your coil really 300mH? > >> > >> A nice feature is how easily you can set the output pulse width to > >> minimize > >> power usage. > >> > >> For your amusement, here's a version of your circuit with a MOSFET > >> output. > >> (I injected the simulated coil pick-up voltage slightly differently.) > >> > >> > >> <snip LTSpice listing> > >> > >> Interesting, and you saved another part. But it doesn't seem to work on a > >> 2 > >> volt battery. I'm figuring a couple AA cells will be close to dead at 1 > >> volt > >> each, so I need the thing to operate on 2 volts.. > > > > Just tried it--works fine for me @ 1.0 V. But you'll prefer the jellybean > > BJT's; this was just for fun. > > > >> The coil inductance may be lower at 150mH. I just looked at this air core > >> inductance calculator and plugged in the appriximate values of 150mH and > >> 1/4 > >> inch for both inner coil diameter and length.and wire gauge of #38. It > >> shows > >> 3300 turns and about 300 ohms of resistance, which is about what I have. > >> So, > >> the inductance may be lower at 150mH. > > > > The key thing will be whether the new coil gives the pendulum > > enough of a 'push' to keep 'er going. Then you can tweak the > > drive pulse width to save power. > > > >> The air core calculator is here: > >> > >> http://www.pronine.ca/multind.htm > > > > Cheers, > > James Arthur > > So,what am I doing wrong? All I changed was V1 to 2 volts and I get an > output pulse of 200mV and a width of 1mS. That won't work.With V1=2V I get a 2V x 17mS pulse at the coil. Did you change FETs? The PMOS has to be a low Vgs(th) type. Or maybe you're measuring at the wrong place? Or disconnecting the positive feedback loop like you were before, for measuring? The output pulse width is down to 2mS @ V1=1V. It's obviously running out of gas--I wasn't trying to make it work at 0.5V/cell--but it is still *running*, and not laying idle. Ideally pulse-width would vary inversely with Vcc, providing constant mechanical drive over the battery life. But that takes more parts. :-) Besides--you might want reduced swing as a battery-state indication so the user can see when his batteries are running out of steam. Cheers, James Arthur
Reply by ●December 29, 20162016-12-29
On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote:> <dagmargoodboat@yahoo.com> wrote in message > news:b954d064-5417-4629-9805-6296310ca870@googlegroups.com... > > On Friday, December 23, 2016 at 8:05:37 PM UTC-5, Bill Bowden wrote: > >> <dagmargoodboat@yahoo.com> wrote in message > >> > Then you could use NT's circuit, but replace R1 with a schottky. > >> > > >> > That does exactly what you want, temperature-compensated for free. > >> > > >> > Cheers, > >> > James > >> > >> Yes, that might work R2 is fairly high at 100K or more so the drop on a > >> schottky is only 150mV. If I use 1N4148, the drop is about right at 450mV > >> at > >> room temp.I can get it down to 400mV if R2 is 200K. But it looks ok at > >> 450mV > >> and switches the transistor rail to rail with a 250mV input. It's > >> something > >> to play with. > > > > A small-signal schottky will have a higher Vf at low current than that > > 1n5823 you're thinking of using :-). > > > > But yes, you could also use a 'fat' diode (such as a 1n4001) at low > > current > > instead of a small-signal schottky, and get a suitably smaller Vf. > > > >> But right now I have to get Xmas out of the way and get my > >> relatives something so I can show up at Xmas dinner carrying at least 2 > >> gifts. I'm considering a large box of chocolates, or a Hickory Farm box > >> of > >> sausage and cheese, or a box of egg rolls from an Asian market. Plus a > >> gift > >> card of some value. I sent my grand Niece and Nephew each a 50 dollar > >> bill > >> in a card. I hope the postman doesn't rip it off. > > > > Don't forget, there's always room for Jello! > > > > Cheers, > > James Arthur > > I think I have a working modle using just two transistors. The pulse shape > is not the best, but better than the original magazine circuit. .Total part > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of the > old ones at Doc's. I sold my original for $25 a couple weeks ago. I think > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. > > Version 4 > SHEET 1 992 680 > WIRE 176 -48 80 -48 > WIRE 288 -48 176 -48 > WIRE 464 -48 288 -48 > WIRE 544 -48 464 -48 > WIRE 544 -16 544 -48 > WIRE -64 0 -208 0 > WIRE -16 0 -64 0 > WIRE 464 0 464 -48 > WIRE 80 16 80 -48 > WIRE -208 32 -208 0 > WIRE 176 48 176 32 > WIRE 208 48 176 48 > WIRE 288 48 288 32 > WIRE 288 48 272 48 > WIRE 304 48 288 48 > WIRE 400 48 384 48 > WIRE -64 96 -64 64 > WIRE -16 96 -16 80 > WIRE -16 96 -64 96 > WIRE 176 96 176 48 > WIRE -16 144 -16 96 > WIRE -16 144 -32 144 > WIRE 0 144 -16 144 > WIRE 80 144 80 96 > WIRE 80 144 64 144 > WIRE 112 144 80 144 > WIRE -176 192 -176 144 > WIRE -16 240 -16 144 > WIRE 464 240 464 96 > WIRE 464 240 -16 240 > FLAG 544 64 0 > FLAG 176 192 0 > FLAG -176 272 0 > FLAG -208 32 0 > SYMBOL pnp 400 96 M180 > WINDOW 3 -24 -21 Left 0 > WINDOW 0 -264 -273 Left 0 > SYMATTR Value 2N3906 > SYMATTR InstName Q1 > SYMBOL npn 112 96 R0 > WINDOW 0 324 -47 Left 0 > WINDOW 3 35 47 Left 0 > SYMATTR InstName Q2 > SYMATTR Value 2N3904 > SYMBOL voltage 544 -32 R0 > WINDOW 123 0 0 Left 0 > WINDOW 39 0 0 Left 0 > SYMATTR InstName V1 > SYMATTR Value 3.2 > SYMBOL diode 64 128 R90 > WINDOW 0 0 32 VBottom 0 > WINDOW 3 32 32 VTop 0 > SYMATTR InstName D1 > SYMATTR Value 1N4148 > SYMBOL voltage -176 176 R0 > WINDOW 3 53 98 Left 0 > WINDOW 123 0 0 Left 0 > WINDOW 39 57 124 Left 0 > WINDOW 0 -73 49 Left 0 > SYMATTR Value PULSE(0 4.5 0 1e-6 1e-6 .001 .3 5) > SYMATTR SpiceLine Rser=0 > SYMATTR InstName V2 > SYMBOL res 160 -64 R0 > WINDOW 0 -63 435 Left 0 > WINDOW 3 37 57 Left 0 > SYMATTR InstName R2 > SYMATTR Value 10k > SYMBOL cap 272 32 R90 > WINDOW 0 -99 47 VBottom 0 > WINDOW 3 32 32 VTop 0 > SYMATTR InstName C1 > SYMATTR Value 4.7µ > SYMBOL res 64 0 R0 > WINDOW 0 154 371 Left 0 > WINDOW 3 39 50 Left 0 > SYMATTR InstName R3 > SYMATTR Value 220k > SYMBOL res -16 128 R90 > WINDOW 0 0 56 VBottom 0 > WINDOW 3 32 56 VTop 0 > SYMATTR InstName R4 > SYMATTR Value 1000k > SYMBOL cap -112 128 R90 > WINDOW 0 0 32 VBottom 0 > WINDOW 3 32 32 VTop 0 > SYMATTR InstName C2 > SYMATTR Value .1µ > SYMBOL res 272 -64 R0 > WINDOW 0 -256 433 Left 0 > WINDOW 3 38 55 Left 0 > SYMATTR InstName R5 > SYMATTR Value 10k > SYMBOL ind -32 -16 R0 > WINDOW 0 216 386 Left 0 > WINDOW 3 41 49 Left 0 > SYMATTR InstName L1 > SYMATTR Value .3 > SYMATTR SpiceLine Rser=300 > SYMBOL diode -80 0 R0 > WINDOW 3 -90 38 Left 0 > WINDOW 0 331 372 Left 0 > SYMATTR Value 1N4148 > SYMATTR InstName D2 > SYMBOL res 400 32 R90 > WINDOW 0 352 328 VBottom 0 > WINDOW 3 32 56 VTop 0 > SYMATTR InstName R1 > SYMATTR Value 2k > TEXT -120 328 Left 0 !.tran 2sWhat magazine article project are you doing?
Reply by ●December 29, 20162016-12-29
On Thursday, December 29, 2016 at 9:09:39 AM UTC-5, bloggs.fred...@gmail.com wrote:> On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote: > > <dagmargoodboat@yahoo.com> wrote in message > > news:b954d064-5417-4629-9805-6296310ca870@googlegroups.com... > > > On Friday, December 23, 2016 at 8:05:37 PM UTC-5, Bill Bowden wrote: > > >> <dagmargoodboat@yahoo.com> wrote in message > > >> > Then you could use NT's circuit, but replace R1 with a schottky. > > >> > > > >> > That does exactly what you want, temperature-compensated for free. > > >> > > > >> > Cheers, > > >> > James > > >> > > >> Yes, that might work R2 is fairly high at 100K or more so the drop on a > > >> schottky is only 150mV. If I use 1N4148, the drop is about right at 450mV > > >> at > > >> room temp.I can get it down to 400mV if R2 is 200K. But it looks ok at > > >> 450mV > > >> and switches the transistor rail to rail with a 250mV input. It's > > >> something > > >> to play with. > > > > > > A small-signal schottky will have a higher Vf at low current than that > > > 1n5823 you're thinking of using :-). > > > > > > But yes, you could also use a 'fat' diode (such as a 1n4001) at low > > > current > > > instead of a small-signal schottky, and get a suitably smaller Vf. > > > > > >> But right now I have to get Xmas out of the way and get my > > >> relatives something so I can show up at Xmas dinner carrying at least 2 > > >> gifts. I'm considering a large box of chocolates, or a Hickory Farm box > > >> of > > >> sausage and cheese, or a box of egg rolls from an Asian market. Plus a > > >> gift > > >> card of some value. I sent my grand Niece and Nephew each a 50 dollar > > >> bill > > >> in a card. I hope the postman doesn't rip it off. > > > > > > Don't forget, there's always room for Jello! > > > > > > Cheers, > > > James Arthur > > > > I think I have a working modle using just two transistors. The pulse shape > > is not the best, but better than the original magazine circuit. .Total part > > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of the > > old ones at Doc's. I sold my original for $25 a couple weeks ago. I think > > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. > > > > Version 4 > > SHEET 1 992 680 > > WIRE 176 -48 80 -48 > > WIRE 288 -48 176 -48 > > WIRE 464 -48 288 -48 > > WIRE 544 -48 464 -48 > > WIRE 544 -16 544 -48 > > WIRE -64 0 -208 0 > > WIRE -16 0 -64 0 > > WIRE 464 0 464 -48 > > WIRE 80 16 80 -48 > > WIRE -208 32 -208 0 > > WIRE 176 48 176 32 > > WIRE 208 48 176 48 > > WIRE 288 48 288 32 > > WIRE 288 48 272 48 > > WIRE 304 48 288 48 > > WIRE 400 48 384 48 > > WIRE -64 96 -64 64 > > WIRE -16 96 -16 80 > > WIRE -16 96 -64 96 > > WIRE 176 96 176 48 > > WIRE -16 144 -16 96 > > WIRE -16 144 -32 144 > > WIRE 0 144 -16 144 > > WIRE 80 144 80 96 > > WIRE 80 144 64 144 > > WIRE 112 144 80 144 > > WIRE -176 192 -176 144 > > WIRE -16 240 -16 144 > > WIRE 464 240 464 96 > > WIRE 464 240 -16 240 > > FLAG 544 64 0 > > FLAG 176 192 0 > > FLAG -176 272 0 > > FLAG -208 32 0 > > SYMBOL pnp 400 96 M180 > > WINDOW 3 -24 -21 Left 0 > > WINDOW 0 -264 -273 Left 0 > > SYMATTR Value 2N3906 > > SYMATTR InstName Q1 > > SYMBOL npn 112 96 R0 > > WINDOW 0 324 -47 Left 0 > > WINDOW 3 35 47 Left 0 > > SYMATTR InstName Q2 > > SYMATTR Value 2N3904 > > SYMBOL voltage 544 -32 R0 > > WINDOW 123 0 0 Left 0 > > WINDOW 39 0 0 Left 0 > > SYMATTR InstName V1 > > SYMATTR Value 3.2 > > SYMBOL diode 64 128 R90 > > WINDOW 0 0 32 VBottom 0 > > WINDOW 3 32 32 VTop 0 > > SYMATTR InstName D1 > > SYMATTR Value 1N4148 > > SYMBOL voltage -176 176 R0 > > WINDOW 3 53 98 Left 0 > > WINDOW 123 0 0 Left 0 > > WINDOW 39 57 124 Left 0 > > WINDOW 0 -73 49 Left 0 > > SYMATTR Value PULSE(0 4.5 0 1e-6 1e-6 .001 .3 5) > > SYMATTR SpiceLine Rser=0 > > SYMATTR InstName V2 > > SYMBOL res 160 -64 R0 > > WINDOW 0 -63 435 Left 0 > > WINDOW 3 37 57 Left 0 > > SYMATTR InstName R2 > > SYMATTR Value 10k > > SYMBOL cap 272 32 R90 > > WINDOW 0 -99 47 VBottom 0 > > WINDOW 3 32 32 VTop 0 > > SYMATTR InstName C1 > > SYMATTR Value 4.7µ > > SYMBOL res 64 0 R0 > > WINDOW 0 154 371 Left 0 > > WINDOW 3 39 50 Left 0 > > SYMATTR InstName R3 > > SYMATTR Value 220k > > SYMBOL res -16 128 R90 > > WINDOW 0 0 56 VBottom 0 > > WINDOW 3 32 56 VTop 0 > > SYMATTR InstName R4 > > SYMATTR Value 1000k > > SYMBOL cap -112 128 R90 > > WINDOW 0 0 32 VBottom 0 > > WINDOW 3 32 32 VTop 0 > > SYMATTR InstName C2 > > SYMATTR Value .1µ > > SYMBOL res 272 -64 R0 > > WINDOW 0 -256 433 Left 0 > > WINDOW 3 38 55 Left 0 > > SYMATTR InstName R5 > > SYMATTR Value 10k > > SYMBOL ind -32 -16 R0 > > WINDOW 0 216 386 Left 0 > > WINDOW 3 41 49 Left 0 > > SYMATTR InstName L1 > > SYMATTR Value .3 > > SYMATTR SpiceLine Rser=300 > > SYMBOL diode -80 0 R0 > > WINDOW 3 -90 38 Left 0 > > WINDOW 0 331 372 Left 0 > > SYMATTR Value 1N4148 > > SYMATTR InstName D2 > > SYMBOL res 400 32 R90 > > WINDOW 0 352 328 VBottom 0 > > WINDOW 3 32 56 VTop 0 > > SYMATTR InstName R1 > > SYMATTR Value 2k > > TEXT -120 328 Left 0 !.tran 2s > > What magazine article project are you doing?It's not for a magazine project AFAIK, though Bill has published projects in hobby magazines. Bill's experimenting with a perpetual pendulum and with a one-pole motor based on similar coils / drivers, both(?) inspired by a solar-powered device described in an article Bill listed above(*) (from Nuts N Volts magazine). He's optimizing, improving, and adapting. (*) http://www.bowdenshobbycircuits.info/swinger.htm Bill demonstrates these to kids and the general public for the sheer pleasure, inspiring, fascinating and delighting folks, introducing them to the magic of electronics. His hobby website is bowdenshobbycircuits.info, full of great projects for young electrophiles. Cheers, James Arthur
Reply by ●December 29, 20162016-12-29
On Thursday, December 29, 2016 at 9:56:11 AM UTC-5, dagmarg...@yahoo.com wrote:> On Thursday, December 29, 2016 at 9:09:39 AM UTC-5, bloggs.fred...@gmail.com wrote: > > On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden wrote: > > > <dagmargoodboat@yahoo.com> wrote in message > > > news:b954d064-5417-4629-9805-6296310ca870@googlegroups.com... > > > > On Friday, December 23, 2016 at 8:05:37 PM UTC-5, Bill Bowden wrote: > > > >> <dagmargoodboat@yahoo.com> wrote in message > > > >> > Then you could use NT's circuit, but replace R1 with a schottky. > > > >> > > > > >> > That does exactly what you want, temperature-compensated for free. > > > >> > > > > >> > Cheers, > > > >> > James > > > >> > > > >> Yes, that might work R2 is fairly high at 100K or more so the drop on a > > > >> schottky is only 150mV. If I use 1N4148, the drop is about right at 450mV > > > >> at > > > >> room temp.I can get it down to 400mV if R2 is 200K. But it looks ok at > > > >> 450mV > > > >> and switches the transistor rail to rail with a 250mV input. It's > > > >> something > > > >> to play with. > > > > > > > > A small-signal schottky will have a higher Vf at low current than that > > > > 1n5823 you're thinking of using :-). > > > > > > > > But yes, you could also use a 'fat' diode (such as a 1n4001) at low > > > > current > > > > instead of a small-signal schottky, and get a suitably smaller Vf. > > > > > > > >> But right now I have to get Xmas out of the way and get my > > > >> relatives something so I can show up at Xmas dinner carrying at least 2 > > > >> gifts. I'm considering a large box of chocolates, or a Hickory Farm box > > > >> of > > > >> sausage and cheese, or a box of egg rolls from an Asian market. Plus a > > > >> gift > > > >> card of some value. I sent my grand Niece and Nephew each a 50 dollar > > > >> bill > > > >> in a card. I hope the postman doesn't rip it off. > > > > > > > > Don't forget, there's always room for Jello! > > > > > > > > Cheers, > > > > James Arthur > > > > > > I think I have a working modle using just two transistors. The pulse shape > > > is not the best, but better than the original magazine circuit. .Total part > > > count is 10 verses 12 with the old circuit so I saved 2 parts. And it > > > triggers on 250mV. Haven't built it yet, I'll wait until I sell one of the > > > old ones at Doc's. I sold my original for $25 a couple weeks ago. I think > > > I've sold 6 for around $20 each, so I'm ahead $120 in a couple years. > > > > > > Version 4 > > > SHEET 1 992 680 > > > WIRE 176 -48 80 -48 > > > WIRE 288 -48 176 -48 > > > WIRE 464 -48 288 -48 > > > WIRE 544 -48 464 -48 > > > WIRE 544 -16 544 -48 > > > WIRE -64 0 -208 0 > > > WIRE -16 0 -64 0 > > > WIRE 464 0 464 -48 > > > WIRE 80 16 80 -48 > > > WIRE -208 32 -208 0 > > > WIRE 176 48 176 32 > > > WIRE 208 48 176 48 > > > WIRE 288 48 288 32 > > > WIRE 288 48 272 48 > > > WIRE 304 48 288 48 > > > WIRE 400 48 384 48 > > > WIRE -64 96 -64 64 > > > WIRE -16 96 -16 80 > > > WIRE -16 96 -64 96 > > > WIRE 176 96 176 48 > > > WIRE -16 144 -16 96 > > > WIRE -16 144 -32 144 > > > WIRE 0 144 -16 144 > > > WIRE 80 144 80 96 > > > WIRE 80 144 64 144 > > > WIRE 112 144 80 144 > > > WIRE -176 192 -176 144 > > > WIRE -16 240 -16 144 > > > WIRE 464 240 464 96 > > > WIRE 464 240 -16 240 > > > FLAG 544 64 0 > > > FLAG 176 192 0 > > > FLAG -176 272 0 > > > FLAG -208 32 0 > > > SYMBOL pnp 400 96 M180 > > > WINDOW 3 -24 -21 Left 0 > > > WINDOW 0 -264 -273 Left 0 > > > SYMATTR Value 2N3906 > > > SYMATTR InstName Q1 > > > SYMBOL npn 112 96 R0 > > > WINDOW 0 324 -47 Left 0 > > > WINDOW 3 35 47 Left 0 > > > SYMATTR InstName Q2 > > > SYMATTR Value 2N3904 > > > SYMBOL voltage 544 -32 R0 > > > WINDOW 123 0 0 Left 0 > > > WINDOW 39 0 0 Left 0 > > > SYMATTR InstName V1 > > > SYMATTR Value 3.2 > > > SYMBOL diode 64 128 R90 > > > WINDOW 0 0 32 VBottom 0 > > > WINDOW 3 32 32 VTop 0 > > > SYMATTR InstName D1 > > > SYMATTR Value 1N4148 > > > SYMBOL voltage -176 176 R0 > > > WINDOW 3 53 98 Left 0 > > > WINDOW 123 0 0 Left 0 > > > WINDOW 39 57 124 Left 0 > > > WINDOW 0 -73 49 Left 0 > > > SYMATTR Value PULSE(0 4.5 0 1e-6 1e-6 .001 .3 5) > > > SYMATTR SpiceLine Rser=0 > > > SYMATTR InstName V2 > > > SYMBOL res 160 -64 R0 > > > WINDOW 0 -63 435 Left 0 > > > WINDOW 3 37 57 Left 0 > > > SYMATTR InstName R2 > > > SYMATTR Value 10k > > > SYMBOL cap 272 32 R90 > > > WINDOW 0 -99 47 VBottom 0 > > > WINDOW 3 32 32 VTop 0 > > > SYMATTR InstName C1 > > > SYMATTR Value 4.7µ > > > SYMBOL res 64 0 R0 > > > WINDOW 0 154 371 Left 0 > > > WINDOW 3 39 50 Left 0 > > > SYMATTR InstName R3 > > > SYMATTR Value 220k > > > SYMBOL res -16 128 R90 > > > WINDOW 0 0 56 VBottom 0 > > > WINDOW 3 32 56 VTop 0 > > > SYMATTR InstName R4 > > > SYMATTR Value 1000k > > > SYMBOL cap -112 128 R90 > > > WINDOW 0 0 32 VBottom 0 > > > WINDOW 3 32 32 VTop 0 > > > SYMATTR InstName C2 > > > SYMATTR Value .1µ > > > SYMBOL res 272 -64 R0 > > > WINDOW 0 -256 433 Left 0 > > > WINDOW 3 38 55 Left 0 > > > SYMATTR InstName R5 > > > SYMATTR Value 10k > > > SYMBOL ind -32 -16 R0 > > > WINDOW 0 216 386 Left 0 > > > WINDOW 3 41 49 Left 0 > > > SYMATTR InstName L1 > > > SYMATTR Value .3 > > > SYMATTR SpiceLine Rser=300 > > > SYMBOL diode -80 0 R0 > > > WINDOW 3 -90 38 Left 0 > > > WINDOW 0 331 372 Left 0 > > > SYMATTR Value 1N4148 > > > SYMATTR InstName D2 > > > SYMBOL res 400 32 R90 > > > WINDOW 0 352 328 VBottom 0 > > > WINDOW 3 32 56 VTop 0 > > > SYMATTR InstName R1 > > > SYMATTR Value 2k > > > TEXT -120 328 Left 0 !.tran 2s > > > > What magazine article project are you doing? > > It's not for a magazine project AFAIK, though Bill has published projects > in hobby magazines. > > Bill's experimenting with a perpetual pendulum and with a one-pole motor > based on similar coils / drivers, both(?) inspired by a solar-powered > device described in an article Bill listed above(*) (from Nuts N Volts > magazine). He's optimizing, improving, and adapting. > > (*) http://www.bowdenshobbycircuits.info/swinger.htm > > Bill demonstrates these to kids and the general public for the sheer > pleasure, inspiring, fascinating and delighting folks, introducing them > to the magic of electronics. > > His hobby website is bowdenshobbycircuits.info, full of great projects for > young electrophiles. > > Cheers, > James ArthurOkay, thanks- saw that one earlier, looks fun.
Reply by ●December 29, 20162016-12-29
<dagmargoodboat@yahoo.com> wrote in message news:79e4c1d0-24f7-4b44-a591-1b584b267b6d@googlegroups.com...> On Wednesday, December 28, 2016 at 10:00:45 PM UTC-5, Bill Bowden wrote: >> So,what am I doing wrong? All I changed was V1 to 2 volts and I get an >> output pulse of 200mV and a width of 1mS. That won't work. > > With V1=2V I get a 2V x 17mS pulse at the coil. > > Did you change FETs? The PMOS has to be a low Vgs(th) type. Or maybe > you're measuring at the wrong place? Or disconnecting the positive > feedback loop like you were before, for measuring? > > The output pulse width is down to 2mS @ V1=1V. It's obviously running > out of gas--I wasn't trying to make it work at 0.5V/cell--but it is > still *running*, and not laying idle. > > Ideally pulse-width would vary inversely with Vcc, providing constant > mechanical drive over the battery life. But that takes more parts. :-) > Besides--you might want reduced swing as a battery-state indication so > the user can see when his batteries are running out of steam. > > Cheers, > James ArthurYes, I think you are right. I just tried the sim again and it works fine on 2 volts. I think I had disconnected the cap for some reason and forgot to reattach it. I did have several adult beverages last night, so my focus wasn't the best.
