Big Joule Theif

[slayer007]

Hello I am new here, and just recently I discovered the joule thief circuit.
I tried to duplicate it from this video

YouTube - Make a Joule Thief

I had no luck thou. The voltage measured on the collector/emitter is exactly the same as the input voltage.

Does anyone have any idea what could be wrong.

transistor 2n3904
1k resistor
torrid from a cfl lamp
telephone wire 10 turns
input voltage 2.4 v from two AAA batteries.

Thanks in advance.

It sounds like you may have one of your coil winding backwards.

Try reversing the polarity on one of your coil windings.

The base winding and the collector winding should be wound on opposite directions.

[pentiger]

Hi Slayer,

I did everything exactly like in the video from Makezine

two wires run together trough the toroid and then one of each opposite ends soldered together.

I re-winded it several times and still the same end result, I may have to post a video of what I am doing.

Thanks for the reply.

[Tectalabyss]

It sounds like you may have one of your coil winding backwards.

Try reversing the polarity on one of your coil windings.

The base winding and the collector winding should be wound on opposite directions.

Hi Slayer Thanks for helping pentiger I had a stroke three months ago and my thoughts get messed up some times. My Hobie in electronics have kept me from going nuts while trying to make a recovery Tec

[kooler]

Hi Slayer,

I did everything exactly like in the video from Makezine

Thanks for the reply.

hey..,
i can't tell from the pic on the resistor.. does it look like this one below
cause everything else looks good.. if it does try a small cap across the resistor.. like a 0.1 uf or lower..

robbie

[Tectalabyss]

hey..,
i can't tell from the pic on the resistor.. does it look like this one below
cause everything else looks good.. if it does try a small cap across the resistor.. like a 0.1 uf or lower..

robbie

Hello PenTiger.Just a though if the resistor is right than switch the wires on your resistor and led also did you check the led with a three volt battery? just to make sure it was good I've had that happen before. Hope this helps Tec

[pentiger]

Thanks all for the replies. The resistor is 1k just like in the picture, besides I measured it. Maybe the transistor is not good. I purchased a 2n3055 an I will try again. One coil I know I messed up because I used uncoated wire and it shorted out. But on the other hand when I used a telephone wire I got same result.
Tomorrow I will be able to post pictures of the multimeter.

In regards to LED, it should be fine, it didn't light up from the circuit, because the voltage wasn't enough.

Thanks again to everyone for help. I will have to try couple more times.

pentiger

[Tectalabyss]

Dont give up

Thanks all for the replies. The resistor is 1k just like in the picture, besides I measured it. Maybe the transistor is not good. I purchased a 2n3055 an I will try again. One coil I know I messed up because I used uncoated wire and it shorted out. But on the other hand when I used a telephone wire I got same result.
Tomorrow I will be able to post pictures of the multimeter.

In regards to LED, it should be fine, it didn't light up from the circuit, because the voltage wasn't enough.

Thanks again to everyone for help. I will have to try couple more times.

pentiger

Hello PenTiger
You are almost there.I take two wires of of the same length and tape one end of the two together, then I start clockwise wrapping them around the coil. when done " (Example One red wire & one black wire) " ( Take The Red wire from the two you taped together and soldier it to to the black wire you did not have taped.) That leaves you with a red and a black With a piece of tape on it. no way to get them messed up. from there just follow how to make a JT.As far as Transistors I have used 2n3904/2n3906/2n2222.I have only used a 2n3055 power transistor for making HV using an automotive ING coil, Now that will run a Cfl light But with my setup you need at least a 12 volt car battery.any way once you get your JT working then you can start working on a secondary winding for your cfl light. look on youtube . Hope some of this helps. Tec

[pentiger]

Hello PenTiger
You are almost there.I take two wires of of the same length and tape one end of the two together, then I start clockwise wrapping them around the coil. when done " (Example One red wire & one black wire) " ( Take The Red wire from the two you taped together and soldier it to to the black wire you did not have taped.) That leaves you with a red and a black With a piece of tape on it. no way to get them messed up. from there just follow how to make a JT.As far as Transistors I have used 2n3904/2n3906/2n2222.I have only used a 2n3055 power transistor for making HV using an automotive ING coil, Now that will run a Cfl light But with my setup you need at least a 12 volt car battery.any way once you get your JT working then you can start working on a secondary winding for your cfl light. look on youtube . Hope some of this helps. Tec

Tec, thanks for all the details.

To let you know I did it finally. Both transistors worked with 1.3v AAA.
2n3904 lit up the LED, (by the way the LED I used before didn't work). 2n3055 worked even better from what I saw.

This test was a success!!!

Now I need a bigger coil to light up a CFL or LED bulb.

Thanks again for all your help.

pentiger

[Tectalabyss]

Tec, thanks for all the details.

To let you know I did it finally. Both transistors worked with 1.3v AAA.
2n3904 lit up the LED, (by the way the LED I used before didn't work). 2n3055 worked even better from what I saw.

This test was a success!!!

Now I need a bigger coil to light up a CFL or LED bulb.

Thanks again for all your help.

pentiger

I Knew you could do it Now If you have a big enough coil you can wind around 150 to 200 turns to get enough voltage to light a cfl this is only one wire magnet wire is the best for this a smaller awg size than what you used for the JT winding. My best advice is to watch a lot of youtube vidios to see the best way to do this you can check out my channel it has a lot of links so you wont have to search everywhere Tectalabyss. type in that when you are on youtubes page. And again Great going. Tec

[NickZ]

Guys:
I've had kindof the same problem with all my Jtc, that is, that there is no induction, and, the voltage between C and E is the same as the battery voltage. I've made about 10 different Jtc now, and they all work the same. 1/2 to 1" toroids from Pc power supplies, as well as a small one from a 13 watt CFL. All using the 2N2222 transistor, and the 1 k ohm resistor. I've tried two different colors of insulated wires to avoid any mix up, as well as 76 turns of 28 gauge magnet wire, on a one inch toroid.
I have one test Jt that has been on a 4 day run, so far, and the Led (single blue one) is still on. The new 3.6v cordless phone battery that is running it, still has 2 volts or so, in it still. Who knows when it will stop, as it seams to like the set up.
So, my Jtc are working but, no induction, at all.
Any ideas on big air core design would be welcome, as I haven't heard much about that.

Tomorrow I'll try a new transistor TIP3055, a different resistor, and I'll also make a new 3 inch bifilar air core, with a secondary. Hopefully that will solve my no induction problem.
I'm working to make a hefty 12 volt Jt that will feed-back to source,and self run, while lighting some Leds. I see some guys are getting close to it...
NickZ

[pentiger]

Guys:
I've had kindof the same problem with all my Jtc, that is, that there is no induction, and, the voltage between C and E is the same as the battery voltage. I've made about 10 different Jtc now, and they all work the same. 1/2 to 1" toroids from Pc power supplies, as well as a small one from a 13 watt CFL. All using the 2N2222 transistor, and the 1 k ohm resistor. I've tried two different colors of insulated wires to avoid any mix up, as well as 76 turns of 28 gauge magnet wire, on a one inch toroid.
I have one test Jt that has been on a 4 day run, so far, and the Led (single blue one) is still on. The new 3.6v cordless phone battery that is running it, still has 2 volts or so, in it still. Who knows when it will stop, as it seams to like the set up.
So, my Jtc are working but, no induction, at all.
Any ideas on big air core design would be welcome, as I haven't heard much about that.

Tomorrow I'll try a new transistor TIP3055, a different resistor, and I'll also make a new 3 inch bifilar air core, with a secondary. Hopefully that will solve my no induction problem.
I'm working to make a hefty 12 volt Jt that will feed-back to source,and self run, while lighting some Leds. I see some guys are getting close to it...
NickZ

Hi NickZ,

I can only tell from my experience. I assume that all your coils work just like mine did. I think that we cannot measure voltage at C/E. The test is to plug a LED to see if it works. I tried several coils and only measured the voltage which was always the same as the input, without actually connecting a LED, which led me to thinking that it doesn't work - I was wrong

LED always lights up from the C/E of the transistor even thou the voltage looks like it didn't change.

Maybe a special multimeter is necessary to measure this voltage.

Yesterday I lit 70 blue LEDs from one AAA battery even thou the voltage measured was 1.3V

Please try plugging some LEDs to your circuit and test it this way.

pentiger

[pentiger]

I Knew you could do it Now If you have a big enough coil you can wind around 150 to 200 turns to get enough voltage to light a cfl this is only one wire magnet wire is the best for this a smaller awg size than what you used for the JT winding. My best advice is to watch a lot of youtube vidios to see the best way to do this you can check out my channel it has a lot of links so you wont have to search everywhere Tectalabyss. type in that when you are on youtubes page. And again Great going. Tec

Hi Tec,

where can I get a 3 1/4 inch toroid for Jeanna's light?

pentiger

[Tectalabyss]

Hi NickZ,

I can only tell from my experience. I assume that all your coils work just like mine did. I think that we cannot measure voltage at C/E. The test is to plug a LED to see if it works. I tried several coils and only measured the voltage which was always the same as the input, without actually connecting a LED, which led me to thinking that it doesn't work - I was wrong

LED always lights up from the C/E of the transistor even thou the voltage looks like it didn't change.

Maybe a special multimeter is necessary to measure this voltage.

Yesterday I lit 70 blue LEDs from one AAA battery even thou the voltage measured was 1.3V

Please try plugging some LEDs to your circuit and test it this way.

pentiger

Way to go Both of you. I think though I am not sure that the JT makes the DC voltage behave like it were AC voltage Thats why your meters wont read correctly. You can take a bridge rectifier and connect it to the led output and get your readings from there or do the same thing off of the output of your secondary winding hope this helps and again Great going Tec

[Tectalabyss]

Hi Tec,

where can I get a 3 1/4 inch toroid for Jeanna's light?

pentiger

I have looked for these myself with no luck you can try ebay or Google.Good Luck and let me know Tec

[NickZ]

@kooler
Thanks for showing the picture of the resistor. I can now tell that my 1k ohm resistor is Not the right one. I have brown, black, and gold (not red), and gold band. So, that may solve my no induction problem. Thanks to Kooler for taking the time to post the pic.
NZ