Big Joule Theif

[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.

[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).

[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

[slayer007]

@Lidmotor

Very Nice video

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

[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.

[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]

@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.

[Inquorate]

Orange neon flashing purple with big julie circuit

Just thought I'd share this, effect hard but not impossible to reproduce, all the contacts have to be clean and gotta move the clip where it is on the neon.

But in effect, this system behaves differently at switch on than when running.

I'd love to see the waveform of purple flash moment on an Oscilloscope.. :-)

Setup
YouTube - Inquorate 24 - slayer's big joule thief

Effect
YouTube - Inquorate 25

[Mutten]

After I get settled in I am going to build a mini JT and see if I can get it to trigger a 2n3055 to pulse my ignition coil backed by a 12v SLA. I'm still messing around with my tesla coil and I want bigger sparks

After I saw Lidmotors scop shots last night, it might work.

Also picked up some disposable camera housings from CVS. They gave me a handful of them for free. Was reading on OU forum people were modifying them to get the same effect. Made it to page 98 last night with some heavy skimming.

[Inquorate]

Video doesn't really capture the brilliance

In the video you can only see the light reflecting on the carpet, but in real life the globe goes super purple. Worth fiddling with till you see it :-)

[Inquorate]

Video doesn't really capture the brilliance

In the video you can only see the light reflecting on the carpet, but in real life the globe goes super purple. Worth fiddling with till you see it :-)

Oh and I believe it happens when switch on off is super quick, once orange glow shows up contact is too long.

[Inquorate]

Can't edit my posts, sorry

Reposted videos to youtube, here's updated links

YouTube - Inquorate 24 - slayer's big joule thief

http://ca.youtube.com/watch?v=NGGd9tJGx0c

YouTube - brighter purple flashes

[sucahyo]

@Inquorate, I also got purple light on my cfl. That is the sign of high BEMF. When the BEMF is high, the CFL show some slight purple color.

Here is the video:
YouTube - Purple ligth shown when BEMF is high


@Mutten, I think you can use your tesla coil too. My circuit with tesla bifilar flat spiral coil produce more bemf than the one with tubular air core coil.

[slayer007]

Here is a video of a little joule theif with a transformer attached to it.
You can allso add more coils or transformers to it.

This can allso be done with the big joule theif.

YouTube - Joule Theif & Transformer

[Mutten]

Shamelessly borrowed from OU.com but I went with the disposable camera circuit for a quick and dirty method of playing around with the JT.

I wanted to see if I could get the circuit to trigger the base of a 2n3055 backed by a 12v SLA to power my tesla coil.

Either the duty cycle is too short or the frequency is too high but I can' get any kind of useful spark even though the 3055 is getting pretty hot.

just FYI if anyone tries this, check your transistor on the camera board. Mine was a D2470 and the pin outs are E C B. I've got a 100ohm resistor at the Base of the 2n3055 triggered by the collector (center pin) from the D2470.


Ignore the top half of the breadboard, that's just my 555 driver circuit I've been playing with, its disconnected in this pic.

stack of pennys are just a heatsink. I've found they help and they sit nicely on the top of the 3055.

http://i197.photobucket.com/albums/a...groo/tesla.jpg