Is joule thief circuit gets overunity?

[Pirate88179]

The JT circuit is an oscillator where the primary function of the oscillator is to energize an inductor.  The inductor then discharges and makes one or 50 LEDs light up and the cycle starts all over again.

That's why a JT can light up 50 LEDs in series.  There is no 'magic' there, it's simply the way a discharging inductor works.

.

Wow, this is short sighted. So then how did I light 400 leds three years ago from a really dead battery?  Nothing special?  You have not been following along then.  Also, resonance is a factor in this circuit.  I do not see how you can claim otherwise.

Bill

[Neo-X]

Wow, this is short sighted. So
then how did I light 400 leds
three years ago from a really
dead battery?  Nothing
special?  You have not been
following along then.  Also, resonance is a factor in this
circuit.  I do not see how you
can claim otherwise.

--End of Quote--

How did you do that? Can u post here your circuits, screenshots and video.?

[Pirate88179]

Wow, this is short sighted. So
then how did I light 400 leds
three years ago from a really
dead battery?  Nothing
special?  You have not been
following along then.  Also, resonance is a factor in this
circuit.  I do not see how you
can claim otherwise.

--End of Quote--

How did you do that? Can u post here your circuits, screenshots and video.?

Check the original Joule Thief topic and my youtube videos (Pirate88179) it is all well documented.  Many others have since surpassed anything I have done with this circuit.  Lasersaber and Gadgetmall to name but two.

Bill

***EDIT***  Here is a video: http://www.youtube.com/watch?v=_RVvdCovYDY

[MileHigh]

Plengo:

I think every time one creates a magnetic field in a coil, in our case a Joule Thief, we have the potential of extracting FREE ENERGY for good. I think you don't agree but I beg you to look into this in more detail.

Well a mechanical analogy for a coil with current flowing through it is a spinning flywheel.  They both store energy and then release it back and exactly the same equations describe their behaviour.  Do you consider a flywheel to be a possible source of free energy?  Many times I have posted a simple test to see if a coil discharges more energy than you put into it but not once has a free energy enthusiast offered to run the test.

A resistor will not present the same magnetic field as an equivalent resistive inductor, why? both will "burn" electricity energy into heat but the inductor will create this "BEMF" for you everytime. Where is the energy to heat and expand the field from, that the resistor does not have but a coil does?

The answer to your question is that the inductor takes extra get energy to get the current flowing but the resistor doesn't require the extra energy.  The extra energy builds up the magnetic field and when you discharge the inductor across a high resistance you get the BEMF spike and that extra energy is released.  It's exactly the same for a mechanical flywheel.  You have to apply torque to it to get it spinning and then when you apply the breaks to the flywheel there is your mechanical "BEMF spike."

Bill:

Wow, this is short sighted. So then how did I light 400 leds three years ago from a really dead battery?  Nothing special?  You have not been following along then.  Also, resonance is a factor in this circuit.  I do not see how you can claim otherwise.

I already addressed that issue when I stated that a JT can light up 50 LEDs in series.  Your nearly dead battery could still get current to flow though the coil.  Then the coil discharged through the 400 LEDs.  A coil has a theoretical limit of infinite voltage generation.

What I assume is that no one in the JT group did a simple test.  Look at the voltage waveform from the discharging JT coil when you have a single LED as the load.  Then look at the waveform for 5 LEDs, then 25 LEDs and then for 100 LEDs.  What you would have observed is that the voltage pulse (and associated current pulse) gets shorter and shorter the more LEDs you have in series.  That's telling you that the coil can store a finite amount of energy and the more LEDs you have in series, the faster that finite amount of energy discharges.

Eventually the pulse gets so narrow that the longs string of LEDs starts to get perceptibly dimmer.  When the coil first starts to discharge, no matter how many LEDs you have in series, the initial current flow is always the same.  So that means that you can put a lot of LEDs in series and they will still light up because the initial amount of current flow is enough to light up each LED in series.  The persistence of human vision is such that you can keep on addling LEDs and your eyes and brain are latching onto the initial bright flash of the LEDs.  Your perception is such that you cannot perceive the fact that the flashing LEDs are flashing on for a shorter and shorter time.  You perceive the brightness as remaining about the same but in actual fact each individual LED is outputting less and less light as you make the string of LEDs longer and longer.

So indeed, nothing special.  Resonance is not a factor in the JT circuit.  It's just an oscillator, nothing more than that.  The oscillator that is at the core of the JT does not resonate in the way resonance is commonly discussed around here.  When the inductor discharges and lights up a bunch of LEDs, that's a 'pulse circuit' function in the same manner that a 555 timer is a device based on pulse circuitry.  Pulse circuits and resonance are two completely separate things.

MileHigh

[bs2012]

I have accedientally build a rather efficient, I believe, Joule Thief.  With a dead 0.8v AA, it could light up 11 led in parallel brightly.  The current draw from the battery is around 38ma.  The led keep light up, though very dim, when battery drop to 0.3v.  I believe the secret is on the toroid as other toroids would draw over 110ma.  I could not replicate it even with the exact ferrite toroid and wires.  I have tried 4 exact ferrite toroid and wires from the same source.

Any idea how to prove if the Joule Thief is overunity?

Any idea how to identify what cause the toroid special?

Any idea how to replicate the toroid?