Is that a joule thief?

[Groundloop]

I would think the primary's would need to be the same weight, the same with the secondary's.

The circuit would be lopsided but the mosfet's are triggered from the bemf of the coils so it should work.

Hi Dave,

You need to use wire thickness on the input that can handle the amperage from the switching circuit.
Same goes for the output, your wire must be thick enough to handle the current usage of the load.

You will not get any energy amplification by using two different wire thickness. The only thing that will
happen is that the thinner wire will go warm if there is too much current through the wire.

But I understand what you are thinking. Is there any way we can "combine" a high voltage/low current with a
low voltage/high current into the same coil. We can't mix that direct but maybe there is another way to do it?

GL.

[Groundloop]

The attached circuit is the closest thing to do what I described in the above post. I call it the Figure-8 circuit.
This circuit will give you a high output voltage with a relative few turns of wire. I have tested the circuit to
light up normal light bulbs and also CFL's etc.

The Figure-8 circuit is a bit tricky to get into tune. The easiest way to do it is to make too many
turns on the center coupling coil. Then connect a constant load to the output coil, e.g. a 220 Volt
15 to 25 Watt light bulb. Then you must check that the center coil is connected the correct way.
The wrong way will give very poor output. Last, you must remove one turn at the time and measure
the output voltage. At the correct number of turns, the output voltage will shoot up, just as in a tuned
LC coil/capacitor tank circuit. Be careful and do not run the circuit close to Hi-Fi, TVs,
computers etc. All metal and all wires regardless of length will get an current generated. Be careful when
running the Figure-8 circuit. The output coil can generate up to 30 Watt (depending on the core size and coils)
of power at many hundred volts. It can harm or kill, so do not touch the circuit when running.

The transistor (high voltage power NPN) you choose to use must be of a high voltage type. 1000 to 1500 Volt
or better. The best result I had was with the BUX80. But this transistor is hard to get hold on. The transistor must
also be mounted onto a heat sink. It is possible to parallel more than one transistor.
The variable resistor must be at least of a 3,5 Watt type. The transistor needs a lot of bias current.

I have made very small versions of the Figure-8 circuit. One was with two tiny Toroid cores driven from a 9 volt
battery. The output coil generated 100 Volt pulsed DC. This was enough to light up a small guttered CFL. :-)

Some theory about the Figure-8 circuit:

The input part is a normal oscillator with a feed-back coil and DC bias to the transistor. At each switch on pulse
in the oscillator there will be generated a positive high voltage spike in the coil. This high voltage spike is feed through
a diode to the middle coupling coil sharing the two Toroid cores. The pulse is then "recycled" back to the positive, thus
we do not waste the voltage spike, making the oscillator COP even higher. The side effect of doing this is that the
transistor has "short circuited" the middle coupling coil at the same time as the input pulse is present in the coil. Shorting
the coupling coil does not require any energy usage at all. We get that for free. This will then transfer a current and voltage
to the second (right) core and we get a output. But, the high voltage spike is overlapped the normal transformer coupling
so that we get an voltage amplification of the output. The voltage amplification is much higher than a normal transformer
ratio. (N1:N2). This means we need just a few turns of wire in the output coil to get a high voltage.

GL.

[Groundloop]

If you want to play with a simple and easy to make Joule Thief, then the attached circuit
is somewhat special and fun. The circuit will give you a "night light" in a ultra bright white
light emitting diode(LED) for weeks from a drained 9 volt battery. The coils in my circuit
was from a guttered CFL circuit board. The circuit uses two separate coils and the coils
needs to be spaced apart a centimeter or so. You can use a 2N2222A in the circuit instead
of the MPSA06.

GL.

[e2matrix]

Hi Groundloop,  Thanks for sharing that figure 8 circuit.  I think I've got everything to build it except the diode.  I've got a C5778 transistor with 1600v 15A ratings and it's a high speed NPN that I think will work fine to replace the NTE2354 and a 225 watt rheostat should handle the variable resistor  
While looking in a folder of saved info from you I found the diagram below from you from 2011 but I can't seem to find any message thread tied to it.  Do you have any idea where I might find more about it?   

[Groundloop]

Hi Groundloop,  Thanks for sharing that figure 8 circuit.  I think I've got everything to build it except the diode.  I've got a C5778 transistor with 1600v 15A ratings and it's a high speed NPN that I think will work fine to replace the NTE2354 and a 225 watt rheostat should handle the variable resistor  
While looking in a folder of saved info from you I found the diagram below from you from 2011 but I can't seem to find any message thread tied to it.  Do you have any idea where I might find more about it?

e2matrix,

Yes, the transistor you list will probably do the job fine. Same goes for your rheostat.

The drawing you posted here was posted in the OUR forum a couple of years ago.
I did delete by bench at OUR due to lack of interest. The above drawing was an idea
only and I have not tried it. But the idea seems good. So if you have one Ferrite toroid
and one Metglas toroid of the approx. same size, then maybe it will work. I don't know.

My test was with two Ferrite cores as shown in my first drawing. The diode is sometimes
called a P600. It is a 1000 Volt 10 Ampere diode. You can use another diode as long as
the diode can handle high voltage and some few ampere pulses. If you want to test this
setup then build the oscillator part first. If the oscillator does not run, then reverse the
trigger coil wires. Then add the middle coil and output coil. Put a load on the output coil,
a 230 VAC 25 Watt light bulb will do fine. Then connect the middle coil. The middle coil
must be reversed if the output is low. Also the middle coil must be tuned to the frequency
of the oscillator. Too many numbers of turns or too few number of turns will give poor output.

GL.