Joule Thief

[jeanna]

Iotayodi,
I have 2 thoughts
1- Maybe there are too many turns. 19 pairs or so is a lot for setting up an oscillation.
2- I bet the problem is the toroid. I had a bum yellow one for my first ferrite toroid and it worked, but feebly, also.

And, I have a question about the circuit.
At the end of my verrry precise pointer,  is the collector side of the led.
I cannot see a connection here, and I cannot see how there could be a connection here. In any case it is under the light if it is there.
One side of the led is on the emitter side of the transistor, and both go to the neg battery.
I can see a lead close enough to believe it is there.

The other side of the light is connected to the collector of the transistor.
If you have a very small jumper going under the light, that would do it, but it is not visible.

jeanna

[xee2]

This lights up fine with 3 volts. Maybe the toroid isn't ferrite. I tried a choke off a monitor cord but thats more cylindrical than toroid. Yes Im using the 2N3904.

If it ligts OK with 3V then it should work with 1.5V if you change the base resistor from 1K to 100 ohms. Your circuit diagram looks OK.

[resonanceman]

Hi guys I've build the Jesus charger but it did not charge my AA battery. I used a 104 cap maybe this is not good. Near the first diode it was giving me about 1.77v but it went down on the two diodes.
Any help please?
Thanks

guruji

I  added each  diode one at a time as I built my Jesus charger .
The voltage should go up  a little  as you add  each diode .

The  Jesus  charger alone is not  enough  to  get the circuit to self charge .
I am working on  getting the part count down .........but my firsr tries required  about 9 coils  most of  them hooked up to provide both  feedback  and flyback .
Most  of those coils  were JT  coils .
I hooked  one  winding  on each  toroid in series  for flyback ........I connected each  of  the other windings  on those coils  to the cap on the Jesus charger . 

Often I connected the   secondary for flyback because it was larger .........but  sometimes  I  used the secondary for  feedback ...... it  all depends on the circuit  and the  coil .
I just  tried connecting   it and checked  the results .




gary

[IotaYodi]

I cannot see a connection here, and I cannot see how there could be a connection here. In any case it is under the light if it is there.

Its there. The Anode is on the collector. The cathode is on the emitter with the negative. I also think its a toroid problem. I may get some of the smaller ones and try those out. Ill try to lower the resistance as Xee2 suggested and see what happens with the other two toroids also.
Frank

[resonanceman]

This lights up fine with 3 volts. Maybe the toroid isn't ferrite. I tried a choke off a monitor cord but thats more cylindrical than toroid. Yes Im using the 2N3904.

IotaYodi

I would  try adding a cap across  your resistor to make a tank circuit
I would also  trade  your resistor for a pot .
I  try several caps  on each coil
I then  run the pot full sweep  .......often it lights best at lowest resistance  ......sometimes it lights  better  at  a higher  resistance .
I have seen a few JTs  that would not run without a cap  across  the resistor .
I have never seen a time that adding a cap  made the JT stop  working .

The caps I use most for the tank  are .1UF and 1 uF     smaller caps  may  be helpful .
Larger caps will sometimes make the  JT blink

gary