Joule Thief

[Cap-Z-ro]

Would a step down transformer also serve the purpose ?

Regartds...

[jeanna]

im still sceptical about joule thief battery charging but i was think of running a bedini motor from a joule thied jeanna i would love the scematic for your0.6ma joule this lowest i have mine is 65ma lol

i start a job monday so soon i should have money to play with one thing i need to get is some 2n3904 transisters and maybe a couple of pots and make some sort of rister wheel with them

I use the jtc with a secondary and no led between the C-E of the transistor.
Other than that,the schematic is not different, but the current from the copper/mg water battery is so low that all that CAN be used is 0.6mA.
If I use a AA, what gets used is more normal, and it lights lots of whites.
The incredible part to me is that it shines a red led from the secondary from so little input volts.

I have been using the 2N2222 that I got after my 3904 all blew from getting stuck by magnets. (my assumption)

If you want to limit the mA going into your jtc, add a rheostat somewhere at the red line coming in from the
+ battery.
I usually use this jtc for multiple white leds, and the jtc takes about 35mA, if I remember.

@gary,
Yes, it might be ok with the bcap
It would take a long time to fill.
This really is restricted input.
The incoming voltage is 1.3v so the bcap would have no problem on that end.
I am using 1F cap and without that none of this works at all.
However, sometimes it takes 30 minutes to fill enough to start up.
But it usually takes less time to keep it filled than it uses so it stays on for weeks after it starts up.
Course it is all free so to speak.
I will make another like the first one which happily ran a jtc that had 2 secondaries with one led each and see what it can do.

The frequency on this water barber pole is 333khz, and the light stays on steady if I add a 150pF cap (101) across the secondary leads. It has a long slow pulse without that cap, but the cap throws the micro amps back and forth enough that the light stays on. It is pretty cool.

That is the angle of this that interests me the most.
I am hoping to get this to work with facility, and maybe someday I will be able to use every last little joule that goes even near the led.
And then... 

thank you,

jeanna

@Gary,
I just re-read your suggestion.
Do you mean to use the bcap across the secondary for the charging side?
I guess that would work.
thanks
j

[Pirate88179]

Goldmine is selling a package of 500 of these 3 volts rechargable new type of batteries:

http://www.goldmine-elec-products.com/prodinfo.asp?number=G13133B&utm_source=Electronic+Goldmine+Newsletter&utm_campaign=a004293e5d-June_1_Warehouse_Stuff6_3_2010&utm_medium=email

It says one quick charge will run an led for an hour.  They are very small and very thin and can be recharged over and over.  This might be a great power source for very small (size) JT projects.  At 3 volts, we could run some leds for a very long time.  I could stick one into my solar garden lights for example.

Just got it in an e-mail from goldmine.

Bill

[guruji]

Resonanceman the setup that I'm using is not with a chip. I just added a 10k instead of the 1n4001 and a 20k between base and collector and it should self oscillate. Although if one has a thick coil as I did last I had to shorten the base coil more.
Oscillations happen on 17ohm base and 28ohm with 6ohm collector in my experience.
Thanks

[dasimpson]

ok i have just dont a test with this little fellow
parts are 1k resister bc337-25 transister 5 base winds 5 collocter winds and 10 pick up coil winds

i used a couple of garden solar panels and 3 1000uf 16v caps in parallel just wonted to see if they would charge to find out the real output of my solar panels
well when i put this jt across the caps droped 0.6 volts and 10ma of current the unit lights but not very bright

my question is if i uped the pickup winds would this make the led brighter or woule removeing the resister do better and try different ones