Joule Thief

[hazens1]

@All

I let the battery sit for about an hour this morning and the voltage went from a loaded 0.412v to an unloaded resting voltage of 1.178v

Triple the voltage unloaded resting for an hour?

Plugged back in and the leds were almost as bright as when the battery was full for about 15 minutes slowly decreasing. I checked the voltage before I left for work and the loaded voltage was down to 0.405v

Seems the extra load from the higher starting voltage sucked it down pretty hard.



@electricme

Your generator expiriment reminds me of a science project I did in school about 20 years back. I had 2 DC motors wired straight together neg to pos, pos to neg. I had a popscicle stick mounted to the shaft of each motor. When I would spin one, the other would spin but not as much. I think the ratio was 3 to 1 or 33% eff in transfering mechanical to electric to mechanical..

I pulled apart a 3.5in floppy drive a few weeks back to reveal a 15 pole 3 phase motor. Pretty interesting stuff..



@xenomorphlabs

Thanks for the info. When I get time, I'm going to have to try messing with some timer circuits.

[innovation_station]

thanks jim for the cartoon pic 

i have a few pics for you and everyone 

the mk2 tuned 6pac in the works ..

ist

[flathunter]

HELP!!!!

I have no idea whats happened with my latest joule thief.  I was using an old toroidal transformer - very large, lots of turns...still dont know how many, in a typical joule thief circuit except i had 2 transistors coupled like a darlington pair (i think ).  They're 2n3904's and i used an old AAA battery. The transformer has a secondary winding which i had wired up to a bridge and 10-15 LEDs.  FirstIy i tried about 50 leds in parrallel with the emitter collector of the second transistor in the pair, and they all flashed very brightly as well as the 10 LEDs on the secondary, which flashed dimmer but faster. I then put a 6 volt motor in place of the 50 LEDs.  To my utter surprise the motor worked, as well as the extra LEDs on the secondary.  I was sooooo happy, I cackled like Dr Frankenstein....This was the most power i'd got with such a battery.  I left it running for about 40 mins, and then put it away till the morning.

Anyway, tried it again this morning, and now i cant get a single LED to light with the circuit, unless i use a big 4.5 volt battery.  Whats happened?  Ive tried changing the transistors, but to no avail.  I've tried the original evil madscientist circuit with no secondary connection....and still nothing.  Its almost like my coil has stopped working....why would this be??  I am just making a silly mistake??


Thanks in advance for any wisdom or help offered.  I'll be getting a video camera for my birthday, and if i can get my JT back in order i'll definitely be making a video.  Thanks to all of you for the continual inspiration 

[innovation_station]

im thinking of building a unit useing all of this stuff

with out any replacable batteries ...  it can work from solar or a hand crank ...  or both ...  lol

choose your path ... 

ist

[flathunter]

HELP!!!!

I have no idea whats happened with my latest joule thief.  I was using an old toroidal transformer - very large, lots of turns...still dont know how many, in a typical joule thief circuit except i had 2 transistors coupled like a darlington pair (i think ).  They're 2n3904's and i used an old AAA battery. The transformer has a secondary winding which i had wired up to a bridge and 10-15 LEDs.  FirstIy i tried about 50 leds in parrallel with the emitter collector of the second transistor in the pair, and they all flashed very brightly as well as the 10 LEDs on the secondary, which flashed dimmer but faster. I then put a 6 volt motor in place of the 50 LEDs.  To my utter surprise the motor worked, as well as the extra LEDs on the secondary.  I was sooooo happy, I cackled like Dr Frankenstein....This was the most power i'd got with such a battery.  I left it running for about 40 mins, and then put it away till the morning.

Anyway, tried it again this morning, and now i cant get a single LED to light with the circuit, unless i use a big 4.5 volt battery.  Whats happened?  Ive tried changing the transistors, but to no avail.  I've tried the original evil madscientist circuit with no secondary connection....and still nothing.  Its almost like my coil has stopped working....why would this be??  I am just making a silly mistake??


Thanks in advance for any wisdom or help offered.  I'll be getting a video camera for my birthday, and if i can get my JT back in order i'll definitely be making a video.  Thanks to all of you for the continual inspiration 

OK...Just tried the 6 V motor on both my little original evilmadscientist toroids, and it works on both with the AAA battery.  So my massive toroid werent doing anything that cant be done with the original design.  So perhaps it aint such a great toroid and it dont matter that it aint working   And its likely that i've made some kind of mistake, and thats why it aint working 

It still gives me great pleasure playing with this blighter.....and I'm still Dr Frankenstein.