On Wednesday, January 4, 2017 at 7:08:40 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
>
> I built the circuit on a proto board and it oscillates at about 4K. If I
> pull out Q2 and plug it back in, the oscillation stops but starts again on
> the first trigger. The layout was messy so I cleaned it up with shorter
> leads but no help. Finally figured out adding another cap (.05uF) from base
> to ground of Q2 fixes the problem. It doesn't seem to matter what the cap
> value is. Works OK with 4.7nF to 0.12uF. so I settled on .05uF since I have
> a bag of those.
Kinda hard to tell which or what you built, but glad you got 'er going.
> Today, I wound a new coil with slightly larger guage and
> length. with 3000 turns and resistance of 180 ohms. I'm installing the
> circuit inside a .cigar box so all components are hidden in the box. It's
> actually not a cigar box but some sort of beauty box for women to do their
> makeup. But it's a nice looking box with inlaid wooden squares I found a
> Cypress for $2. There are 3 compartments and one of the compartments is a
> perfect fit for 2 'D' size batteries. I'm using magnets inside the box to
> hold the swinger posts in place on the top so I don't have to drill any
> holes. It's working fairly well with 7 inch posts and a 12.5 inch diameter
> swing. It's flying and starts with about a 3 inch distance from the coil. It
> didn't do too well with a tiny magnet on the pendulum. so I stacked 4 little
> magnets together and that helped a lot. I'm going to shop for a larger
> magnet to replace the 4 little ones. Efficiency is pretty good. The pulse is
> 20 mS and the idle time is 400mS so the duty is about 5%. The coil draws 17
> mA so the battery drain should be a little less than 1mA. A 'D' size
> alkaline battery is 16 AH so battery life should be 16000 hours or about 667
> days.
Well over a year--that's pretty sweet.
> And another feature is the swinger posts and swinging magnet can all
> be removed from the top surface and stored inside the box so it just looks
> like a closed beauty box. It also convinces people about perpetual motion
> since everything on top of the box can be pulled off showing there are no
> wire connections to the box and it must be magic.. .
Not 'like' magic, that *is* magic. Good for you, Bill. I've seen your
gadgets amaze and delight scores of folks...
Cheers,
James Arthur
Reply by billbowden●January 4, 20172017-01-04
<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
I built the circuit on a proto board and it oscillates at about 4K. If I
pull out Q2 and plug it back in, the oscillation stops but starts again on
the first trigger. The layout was messy so I cleaned it up with shorter
leads but no help. Finally figured out adding another cap (.05uF) from base
to ground of Q2 fixes the problem. It doesn't seem to matter what the cap
value is. Works OK with 4.7nF to 0.12uF. so I settled on .05uF since I have
a bag of those. Today, I wound a new coil with slightly larger guage and
length. with 3000 turns and resistance of 180 ohms. I'm installing the
circuit inside a .cigar box so all components are hidden in the box. It's
actually not a cigar box but some sort of beauty box for women to do their
makeup. But it's a nice looking box with inlaid wooden squares I found a
Cypress for $2. There are 3 compartments and one of the compartments is a
perfect fit for 2 'D' size batteries. I'm using magnets inside the box to
hold the swinger posts in place on the top so I don't have to drill any
holes. It's working fairly well with 7 inch posts and a 12.5 inch diameter
swing. It's flying and starts with about a 3 inch distance from the coil. It
didn't do too well with a tiny magnet on the pendulum. so I stacked 4 little
magnets together and that helped a lot. I'm going to shop for a larger
magnet to replace the 4 little ones. Efficiency is pretty good. The pulse is
20 mS and the idle time is 400mS so the duty is about 5%. The coil draws 17
mA so the battery drain should be a little less than 1mA. A 'D' size
alkaline battery is 16 AH so battery life should be 16000 hours or about 667
days. And another feature is the swinger posts and swinging magnet can all
be removed from the top surface and stored inside the box so it just looks
like a closed beauty box. It also convinces people about perpetual motion
since everything on top of the box can be pulled off showing there are no
wire connections to the box and it must be magic.. .
. .
Reply by billbowden●December 29, 20162016-12-29
<bloggs.fredbloggs.fred@gmail.com> wrote in message
news:93172f92-dfda-4439-9b00-6494301eafd7@googlegroups.com...
On Tuesday, December 27, 2016 at 9:02:21 PM UTC-5, Bill Bowden 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.
>>
<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 Arthur
Yes, 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.
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 Arthur
Okay, thanks- saw that one earlier, looks fun.
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 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?
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 Tom Gardner●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 billbowden●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 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.