Big Joule Theif

[sucahyo]

@sucahyo---The way my trifilar is built I am using the CFL driver third coil like a step down transformer. This gave me LESS voltage but more current to drive the ignition coil.

I see. How about using the car coil directly?

If you modify your car coil by adding center tap, you can make it compatible with joule thief circuit and use it directly without additional coil. I think with car coil high voltage amplification, when you get resonance frequency by changing the base resistance, you can light up several CFL at once and also charging a battery.

I don't know if it would be easy though. Opening the case, finding the primary center, scratch it and solder a cable to it, checking the similarity of the resistance to primary negative and positive, add additional terminal, close it again. The we connect the positive to base resistor, the negative to collector and BEMF load, the center tap to source positive.

[Lidmotor]

Rewiring the trifilar coil

One week ago I discover that Joule Thief work for me when Multivibrator failed. Both charging and neon lighting capability is much better than relay.

I hope with a famous person like Lidmotor making the video, there will be more people see the potential of joule thief and improve it.

For battery charging ability it outperform relay. Charging is very rapid, 4.4V to 8.4V in 3 hour if we remove the neon. mbrownn from imhotepforum advise me that I ruin my battery because of this. Since its broken already, I currently charging it with 150mA BEMF.

@Lidmotor, I think you can still light up the neon even without car coil attached to the third coil.

@sucahyo---The way my trifilar is built I am using the CFL driver third coil like a step down transformer. This gave me LESS voltage but more current to drive the ignition coil. I tried all the different combinations of the three coils before I came up with this way of doing it. I was surprised to see the trifilar go into self- oscillation with different coil combinations. This trifilar could be "engineered" into a specific efficient design for this device using math formulas. Why oh why didn't I pay more attention to that boring EE instructor when I was in school.

[sucahyo]

One week ago I discover that Joule Thief work for me when Multivibrator failed. Both charging and neon lighting capability is much better than relay.

I hope with a famous person like Lidmotor making the video, there will be more people see the potential of joule thief and improve it.

For battery charging ability it outperform relay. Charging is very rapid, 4.4V to 8.4V in 3 hour if we remove the neon. mbrownn from imhotepforum advise me that I ruin my battery because of this. Since its broken already, I currently charging it with 150mA BEMF.

@Lidmotor, I think you can still light up the neon even without car coil attached to the third coil.

[slayer007]

@Lidmotor

Very Nice video

Did you try puting a magnet by the coil and see what happens on the scope?

[Lidmotor]

Slayer's Big Joule Thief---My replication

Well I made the "BIG ONE" today. I hope that other people do this one. Its a really good one. I changed a few things ---added a CFL where the bridge rectifier was and rewired the coils a bit. It is a little different than the little joule thief but maybe even better.
Here is the video of it with scope shots and sounds:

YouTube - Slayer's Big Joule Thief --My Replication

Lidmotor

[sucahyo]

At 12 Volts, you can easily light up neon.
YouTube - Max BEMF at resonance neon with sound

I use 12V CT transformer, but surely this can be replaced with any winding.

At resonance I can get 100mA BEMF for charging or other thing from 260mA input.
YouTube - BEMF and current measurement

I use 100 ohm resistance for base of 2N3055. The frequency change according to charged battery condition but mostly the max BEMF happen when base resistance is low, I use 10K variable resistor.

The BEMF current reduced when the neon light up. I think there is little point of charging battery and lighting up neon at the same time. It is better to choose one of them. If we want to light up neon we should reduce input current as much as possible by using coil which has high resistance (high number of wound).

[slayer007]

Today I tried my small joule theif running off a 1.5v AA.
And hooked a big trifilar coil to it negative going to the transistor and positive
back to the positive on the AA battery.
Then the other two winding both had recifiers attached.
The voltage on one recifier was 4.4v and the other was 5.3v.

I then dumped both of them into a capacitor then hooked it up to a big 12v 80AH battery.
Its only been running for a little while I'll let you know if the voltage goes up in the big battery at all.
And the AA battery only had 1.17v to start.

Edit.
After about 40 min of running the voltage did go up a little well very little like only 100th of a volt.
But the voltage in the AA battery is still the same.
The voltage going to the cap was only from the second coil not the BEMF from the joul theif that is around 2 volts.

[amigo]

Here is a video I just upladed on you tube.

Notice the differance in voltage after a magnet is stuck to the front of the coil.
the back EMF was around 800 to a 1000 volts and the other winding was around 550 volts.
Then after the magnets were attached the voltage went off the board.

YouTube - Big Jouel Theif Slayer007

Hi,

It sounds to me that you have dropped the operating frequency of your JT down to audible levels when you attached the magnets. At least that's what used to happen to me when I was playing with the JT circuits months ago.

Because the frequency is lower voltage went up and the coil is producing audible oscillations instead of ultrasonic. Maybe you should scope this out and see the waveforms, without and with the magnets...

Of course, use a x100 probe or the scope will squeak too, it's final breath

[theremart]

How to make a jewel theif.

Guys,

You may find this video helpful

YouTube - Joule Thief (How to Make a) 005

He has a history of doing good videos and here he shows you step by step...

FYI.

[ApEkV2]

Fixed

That was the problem. Thanks for clearing that up for me Vortex and slayer007.
Here it is now the correct way. The sound they make are really cool.
I found the one circuit with the to126 package transistor worked the best out of the three.



That picture came out bad. But mainly the one in the middle with blue wire is easy to see the change. Thanks again.

[slayer007]

I can't get my joule thief to work. Spent 6 hours on it and 4 different coil, transistor and resistor arrangements and got nothing. Tried the 2n2222, 2n3904, and bd237 to126 transistors.

What's wrong with these?
[ATTACH]1908[/ATTACH]

I'm using cat5 cable for two of the coils

EDIT - I only have one LED I could find, so I am using jumpers for it instead of soldering all the time

@ApEkV2


It looks like you have your coil wired wrong.
According to the circuit I posted anyway.

Instead of wiring the coil ends togeather, wire them togeather from the start of the coil wire with the end one.

So the white and the orange wire would be togeather but one from one end of the coil and the other from the other end of the coil.

I hope that helps if you look at my circuit you can see I have the + of one coil and the - of the other going to the positive of the source.

[Vortex]

I can't get my joule thief to work. Spent 6 hours on it and 4 different coil, transistor and resistor arrangements and got nothing. Tried the 2n2222, 2n3904, and bd237 to126 transistors.

What's wrong with these?
[ATTACH]1908[/ATTACH]

I'm using cat5 cable for two of the coils

EDIT - I only have one LED I could find, so I am using jumpers for it instead of soldering all the time

I had watched this video which said you must use one wire from each pair, opposite wires
off the toroid and solder those together.
For example: If you used a blue and red wire then solder together the blue from one pair and the red from the other pair.
You have soldered together a pair of wires, not one wire from each pair.

That's All I know about it not working.

[ApEkV2]

I can't get my joule thief to work. Spent 6 hours on it and 4 different coil, transistor and resistor arrangements and got nothing. Tried the 2n2222, 2n3904, and bd237 to126 transistors.

What's wrong with these?

Removed the photo (upload space is filling up)

I'm using cat5 cable for two of the coils

EDIT - I only have one LED I could find, so I am using jumpers for it instead of soldering all the time

[peper10]

Draw vs output

Hi to everyone!!
I wonder what`s the draw on the primary??
If you hook the output trough the hv side of the car coil trough a sparkgap
is it possible to get it back to the primary on the lv side of the car coil???
As i can imagine,the output of the secondary is maybe 4000 volts..
Maybe Slayer can clarify this????
Anyway. Just knowing the draw on this system is a start!!!!!


Congradulation to Slayer for is succes.

Alain D

[Inquorate]

Voltage divider

For how to measure voltage that's higher than a meter will go, see my post on 'capacitor Electret other' thread. It's really quite useful for hv