Joule Thief

[jeanna]

Also one thing i dont get on the diagram.. is the secondary only hooked up to the LED? not to the rest of the circuit at all? Collecting the energy from just wrapping around the coil

YUP. Makes me smile every time. I like to call it a free ride. It isn't free because without the battery turning the transistor on and off there would be no lights, but it only costs you what that transistor takes. 

By RGB LED , i mean those ones that change colors.. from red to green to blue.. to whatever mix..

I think those are different colors with different directions. Maybe you will see a different color light when you have it going from the secondary. As long as they were not meant for 12 volt input and include resistors, you should be OK.

Let us know. Do you have a camera?
pics are fun to see.

jeanna

[altrez]

I have a question. I just took a toroid out of my old power supply. Should I place the pickup coil on a bare spot on the new toroid or completely cover the toroid first with the main JT bifilar coil and then wrap the secondary / pickup coil on top of that?

Thanks!

[jeanna]

I have just made another JT and the basic circuit works just fine. I can light 10 LEDS from an old AA battery. I still can not for whatever reason get the pickup coil to work, even with 25 turns of 22 AWG mag wire. That took what felt like forever to wrap lol. I am not giving up, I plan on ordering some better toroids to see what happens.

What puzzles me is that everyone else has such great success with the pickup coil and I have yet to get a flicker from any pickup coil I have added. I have tested with 3 different types of wire and even with 6 different JT builds 1 turn up to 25 on the secondary no luck. 

Thanks for all the help!

So Altraz,
Did the latest page with the flurry of Q n A help?

My first question that I have asked you and others before is, did you remove all those leds from the regular jt place when you try to get the secondary to light a light? You will not be able to have both going at the same time. (well, it is possible, but rare.so do not try for it.)

It is cool to light so many lights from one battery, but if you are using the regular jt position for the lights, you are just letting them suck the amps out of the battery.

Please let me know the answer to this question and we can go from there.

Oh and also I did not get confirmation from you that you had properly sanded down that varnish. It is very thick on the 22awg mag wire and clear so it is really hard to see if it is still getting in the way of connection.

jeanna

BTW, I found that with 11 turns of 2 wires in the regular jt as evilmadscientist directions, ONLY ONE turn on the secondary was enough to light a led. IST replicated this. We both shared pics so others could see. So, yes, the EE's love to talk about the rules. (and I very much appreciate them for being here and explaining the rules, cuz, I sure don't know, ) but the normal rules do not necessarily apply. One turn secondary transformed from 22 turns primary should not be able to turn on any led.

[jeanna]

I have a question. I just took a toroid out of my old power supply. Should I place the pickup coil on a bare spot on the new toroid or completely cover the toroid first with the main JT bifilar coil and then wrap the secondary / pickup coil on top of that?

Thanks!

It is best if the secondary is touching the toroid, so squeeze it in between the bifilar primary turns where you can.

jeanna

[TheNOP]

@dog812 and altrez
once you have a working jt try this.

http://www.overunity.com/index.php?topic=6123.msg162806#msg162806