High Efficiency Joule Thief Type Oscillator

[SkyWatcher]

Hi all, experimenting with something that is easier and low cost to build and experiment with.
This version of the joule thief is based upon the supercharged joule thief circuit i noticed recently.
This modification to the circuit, increases efficiency dramatically.
Similar to the supercharged circuit, when tweaked with the right components, i was able to get the input down to 52%, of a standard joule thief circuit and very similar output.
This resulted in almost no heat discernible anywhere, except the bifilar coil, since that uses 24 awg. magnet wire and probably needs to be slightly thicker wire or less wire used in coil.
The 56Kohm resistor can be temporarily placed in position or a 1 Kohm resistor and then removed, once the circuit is in stable oscillation and the circuit will find its own natural frequency, based upon the non-polarized capacitor value.
I Have a fleet type Lawrence Tseung toroid air coil that i just built and will be testing that soon also.
At the moment, im using a multi-layer air coil with bifilar 24awg. magnet wire.
The goal is to achieve a high Coefficient of Performance, when charging lead acid batteries.
peace love light

[Sawt2]

Hi all, experimenting with something that is easier and low cost to build and experiment with.
This version of the joule thief is based upon the supercharged joule thief circuit i noticed recently.
This modification to the circuit, increases efficiency dramatically.
Similar to the supercharged circuit, when tweaked with the right components, i was able to get the input down to 52%, of a standard joule thief circuit and very similar output.
This resulted in almost no heat discernible anywhere, except the bifilar coil, since that uses 24 awg. magnet wire and probably needs to be slightly thicker wire or less wire used in coil.
The 56Kohm resistor can be temporarily placed in position or a 1 Kohm resistor and then removed, once the circuit is in stable oscillation and the circuit will find its own natural frequency, based upon the non-polarized capacitor value.
I Have a fleet type Lawrence Tseung toroid air coil that i just built and will be testing that soon also.
At the moment, im using a multi-layer air coil with bifilar 24awg. magnet wire.
The goal is to achieve a high Coefficient of Performance, when charging lead acid batteries.
peace love light

Thanks for posting that I just started pulling together some of my old notes about the different joule thief circuits, I like that one I’ll be watching your progress

[SkyWatcher]

Hi Sawt2, thanks for replying, good to have you here.
I'm having some interesting results, with my latest air coil test.
I used 100 feet of 24awg. speaker wire for bifilar coil.
I used a 1-1/2" diameter pvc pipe as coil former, from plumbing section of hardware store.
The coil length is 9-3/4" long, comprised of three coil layers.
There is now 300 nanofarad capacitance across non-polarized capacitor circuit position.

What is interesting is, with this new coil, i can completely remove the 56 Kohm resistor and diode, that comes off the transistor collector and the circuit will start oscillating, without those 2 components ever being connected, with no issues.
Not sure how the circuit oscillation is being triggered now, though i will bet, it has something to do with the higher capacity air coil.
Since the air coil is now 3 layers at 9-3/4" long, i think this new coil is helping to start the oscillations and in some way, probably causing a more natural, harmonious frequency, that is conducive to our higher coefficient of performance aims.
I will continue to experiment with these ideas.
peace love light

[SkyWatcher]

Hi all, been experimenting with this joule thief type circuit and have made some modifications.
It is an interesting circuit, considering the feedback back coil and capacitor, once placed into a natural frequency, will oscillate with only the feedback coil/cap connected.
Again, i do feel the capacitance of this particular air coil, is helping to cause this auto oscillation, based at or near its natural frequency.
The circuit function, changes a little, when the load battery voltage, goes below the input voltage.
peace love light

[SkyWatcher]

Hi all, will updating this thread with another modification of the circuit.
It will be using the splitting the positive again, for greater efficiency.
Also, the coil has changed and now using ferrite toroids stacked together and the
bifilar coil wound over those toroids, solenoid style.
peace love light

[SkyWatcher]

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