Joule Thief

[jeanna]

...
After building my 1st Joule Thief Circuit one of the first things I wondered was..

                What would happen if I fed a Joule Thief into another Joule Thief ?

Heck... make it 5 or 10, but 2 is a good start.

To those knowledgeable of this thread.

           What is the status of experiments pertaining to feeding the JT into another JT into another JT ect?

The Observer

Hi
I also wondered that, and when I said it MK1 said he had found the results very disappointing.
Me too.

In the end I realized that the joule thief works from a low voltage dc source mostly because of the transistor along with some other things.
Go ahead and see for yourself.
Maybe you can figure out a way.
That would be cool.

In fact, I was trying to make that work when I stumbled upon the circuit that did work and so I encourage you to follow your hopes, because you might discover something really great.
And we will all benefit.

jeanna

@tysb3,
Thank you for your explanation.
The "hand scratching" helped me a lot.

-----------
edit add some more...
In the end what enhanced the output a lot and seemingly without end was to add an inductor in series to the secondary output.
If each load had its own inductor the pulses could be enhanced.
Sometimes a cap which "tanked" it would help, but it was not generally necessary for the effect.
The best most enduring effect came from adding an inductor in series with the load or light.
I used those helmholz inductors at first, but found it was better to make my own.

[jadaro2600]

Hi
I also wondered that, and when I said it MK1 said he had found the results very disappointing.
Me too.

In the end I realized that the joule thief works from a low voltage dc source mostly because of the transistor along with some other things.
Go ahead and see for yourself.
Maybe you can figure out a way.
That would be cool.

I've tried this as well, it seems as though impedance plays a role in the dispensation of energy...the voltage is only produced after the flow of energy has ceased in the inductor and thus surges for an exit ...  it is not strong enough to make a significant difference by passing through yet another inductor.

I think the exciter and joule thief circuits should be considered 'irritable electricity' ...

- - - - - -

I found a relatively old book by Texas instruments from 1963 which contains 7 pnp based circuits which, as it stands, do exactly what the joule thief does in principle.  I found it for 50 cents at a local thrift shop.

Some interesting circuits here in this book, perhaps I can translate them to a diagram soon.  Some of them contain multiple transistors.

The book is titled "Transistor Circuit Design".

[tysb3]

I correct pot R2

[The Observer]

Jeanna,

So you tried this?

                      JT---> D=C ----> JT

That is a Diode and Capacitor capturing JT Pulse... then another JT feeding off of said Capacitor.

The Observer

[Flux4Energizer]

@tysb3

Your Double Joule Thief circuit looks nice.
Have you already tested it?
I would like to see how many LED's you can light of it and how much mA it draws.

Keep up the good work!