Joule Thief

[Pirate88179]

jadaro:

Flyback=back emf?  If so, now you are talking Bedini here.  He got it to work with his charger so now maybe we can employ similar ideas to do the same thing with our circuits?

Bill

[jadaro2600]

jadaro:

Flyback=back emf?  If so, now you are talking Bedini here.  He got it to work with his charger so now maybe we can employ similar ideas to do the same thing with our circuits?

Bill

I'll be sure to keep an eye on it; after posting, it dawned on my that flyback might be employed on a second battery, then your Bedini came to mind; the whole thing would be solid state though, there wouldn't be anything moving except the ( holy grail ) magnetic field.

It would likely require a diode diversion from the flyback to the battery, I could use maybe a zener to regulate things? ..but these are funny devices that short out all the pulse.   Anyway, the whole thing may be a flop on account of the losses of current.

As it stands, I think that there's a bit of waste going through from the positive, through the base and out of the emitter, but that's just how electricity flows, lol, now, I already made a jtc work without that resistor, and only on induction - it's a few pages back with a diagram, but this doesn't solve my problems with the transistor being overdriven, voltage wise.

[jeanna]

There seem to be a number of variations on the joule thief design...  insofar as I can tell, there is flyback on the coil-to-base.

Has anyone thought about the flyback pulse charging the battery?  ..this would require the resistor to be behind the coil and at the base of the transistor.

An initial idea.  Diagram Included.  Does anyone have the charging characteristics of a single AA rechargeable battery on hand?

I am confused.

There are other things about this drawing that are different, but you have now put the base resistor where most of us have been putting it all along.

I see there are other differences like the cap and diode parallel to the led which is still in the expensive bjt position. and that cap at the base, well, [edit.] I guess it was gadget that did something like that to his fuji that ran the cfl for 12 hours.

I think way back jesus posted his circuit of his charging jt. I think Bill has already posted it on the circuits pages early, like page 2, maybe.

But really Jadaro, get rid of that led. It just takes power from the battery. A secondary of almost any number of turns - like even one- will light the led for virtually nothing. In fact usually, the amps use goes down when you add the led on the secondary. It certainly is less to run it on the secondary than that bjt place.

Try it, You'll like it! 

jeanna

(I have been installing software today. It is a welcome relief to look at a jtc!)

[Pirate88179]

Jadaro:

I would not worry too much about the transistor being overdriven.  Gadgetmall said he sometimes uses 3 or 4 transistors wired together for protection.  I just saw a youtube vid of a guy that had a simple Bedini motor and, God only knows why, it wasn't turning all that fast, he had something like 50 of the transistors all mounted on a board and wired together.  I am guessing in parallel so I guess that would not raise the operating level that the transistors function, as far as start voltage.  If you are interested, let me know and I will try to hunt up that vid.  Maybe Al can chime in here with a thought or two.

Bill

[Pardon]

this is not a real good drawing but i am new to drawing. this one i have been playing with a little bit. i think it wants more voltage/current but its fun to play with. i have made the leds blink but they are dim by adding a cap.  but as a modified jt i get real good light from the leds. but i can't seem to get them to run in series. and i have not tried a secondary yet.