Coilless Joule Thief

[nicknewbie]

Joule Thief - No toroid, No coil - with Schematic - YouTube

This looks really interesting anyone know if its real?

[citfta]

What a waste of parts

That guy doesn't have a clue what he is doing. In the first place an inductor is a coil. The one he has in the circuit is just a very tiny one. If you want to light an Led with a battery all he has to do is just connect the Led with a resistor in series with the battery and the led will light. In his circuit the current is flowing from the battery through the inductor and right to the Led and back to the battery. As long as you keep that part of the circuit you can take all the rest of the parts off that board and use them for something useful.

Respectfully,
Carroll

[nicknewbie]

Why would he need a resistor? In the circuit the only thing between the battery and led is the small coil. I think there is something going on here, more then just the led being lit right off the battery.

[citfta]

You're correct

Yes you are correct. Besides lighting the led through the inductor he is also letting the transistors oscillate and short out the current going through the led. So he is managing to waste half of the energy of the battery. The guy admits in the comments he didn't even know an inductor was the same as a coil. Build the circuit with just the inductor and the led and watch it work. Then add the other parts and see what happens. The reason I said to use a resistor is because if you use a higher voltage than just a single battery the resistor will limit the current and keep from burning out the led. With only the single battery the inductor will work fine. Depending on the led you could probably run the led right off the battery and forget the inductor too.

Respectfully,
Carroll

[nicknewbie]

I'm going to try to collect the parts to try this because I think it is promising.

[nicknewbie]

This video shows a similar idea with a coil less joule thief. It has a small transformer but no toroid. The only thing the coil is used for is to trigger the transistor once the core is saturated, in this video and the first it is replaced with a properly rated capacitor and resistor.

Joule Ringer on 15volts and 6800uf cap.ASF - YouTube

[Watson]

Joule Thief - No toroid, No coil - with Schematic - YouTube

This looks really interesting anyone know if its real?

Yes, it's real. Like, if you follow the schematic and build it, it should work. But I would use an inductor that is 100 microhenrys. The 4.7 uH he shows is too low. BTW. an inductor is a coil, so saying that it has no coil is not true.