Found on a russian site some strange circuit  https://docs.google.com/file/d/0B7F-FDpM1lG-SXJsRDctN1B6VlE/edit?usp=drive_web page 69 can someone please tell if it might work kind regard if u need translation please ask

K thanks for reply the same image my first post here  i already have a working joule thief for around 2 months now never recharged lighting 4 leds do u know any working tesla switches circuits ? http://www.free-energy.hu/pajert62/Tesla_Battery_Switch_2.PGFED.pdf so slight change u could heat water with 1.6v?

Resonance
When it comes to the joule thief, this term is often misused, inadequately defined, taken out of context, and vastly undervalued.

Resonance of the torroid:
Each ceramic ring has a natural resonant frequency.
This is either determined by the manufacturers specs, or from the materials density and the size and thickness of the core.
This is very important, it is the easiest frequency at which the core will oscillate both physically and magnetically. Meaning at this frequency there are the least amount of losses from charging the core.

Resonance of the coil: this is calculated using the thickness, number of turns, materials, and diameter of the coil. The coil should ideally be specced to match the resonant frequency of the torroid.

Resonance of the switching circuit:
This is when you carefully "tune" the  voltage, transistor and resistance, until you attain a resonant frequency of core/coil.

When all three of these frequencies are resonant,
Meaning the are the same frequency or resonant octaves of one another, the joule thief will operate at maximum efficiency.

Primary, secondary, or more pickup coils can then be added to power various loads, such as lights, heaters, motors, etc.

You can daisy chain multiple JTs through inductive coupling to step up current and/or voltage. Resonance of subsequent JT circuits, when powered by a pickup coil, is less important in most applications. But not to be ignored in terms of load current, losses, delays, capacitance, and general trouble shooting.

This is the most important concept to grasp.
And is what takes your research from being a novelty transformer for low voltage sources to the next level.

Thanks sm0ky2 for the info.. I've been playing with jt's for a while.. and I have never come across an explanation as thorough as yours. . To explain the relationship between core. Coil. And geometry has made me re-think the design of mine (more reading required)
You say that it's possible to connect multi jt's.. what transistor/switch would you use on the latter circuits.  As the power would get increasingly higher.
Thanks Nick

Hi Nick,

I think it is important to note at this point, that latter circuits do not necessarily need secondary transistors. (they can be used)
The switching done by the primary transistor, causes a sinusoidal output on the secondary of the JT. This can be tied directly to a second inductor without the need for switching. Also: adding more transistors, causes more problems with synchronization. i.e. - differences in timing between switching. also, you basically need to rectify the A/C back to D/C to run it through the second transistor.... not needed..

just coil the secondary onto the next inductor.
keep in mind, that core / coil resonance should be maintained also by any secondary transformers..