Is joule thief circuit gets overunity?

[poynt99]

Hi Bill.

Yes, a self-looped arrangement should prove if the device is OU or not.

I've not seen any proposals on how to do it exactly though, have you?

[xee2]

To be precise, allow me to rephrase the above;
In order for real power to manifest and be measured as real power, the current and voltage vectors must be in phase.
Keeping in mind that the stated method is to acquire instantaneous samples of current and voltage, what happens to the product of v(t) x i(t) if they are 90º out of phase? Is the p(t) for these samples not 0W?

This method inherently compensates for the samples where the phase is skewed. In other words, it takes care of the fact that the current and voltage may not always be in-phase. Only those samples that are in phase, or partially in phase will result in a real power product, and if the wave forms are periodic (in 99% of the cases they are), then taking the average of this product will yield an accurate measurement of the over-all average power.

poynt99
If 90 degrees out of phase the real power will be 0 watts. No problem. However when not in phase and not 90 degrees out of phase, the power will be part real and part reactive. Would not the correct method be to compute the dot product between the two complex number values for voltage and current? That way only the in-phase parts of the vectors would be used. I am not real good at math, so I may have this wrong, but I think that would be correct.

In any case, I am not trying to re-design the experiment. I am just trying to understand how the output power is being measured. Thanks for your help.

[Pirate88179]

Hi Bill.

Yes, a self-looped arrangement should prove if the device is OU or not.

I've not seen any proposals on how to do it exactly though, have you?

I have been using the germanium diode method in my most recent efforts.  It is not easy to get the energy flowing in the direction that you want, and to keep it going that way.  In other words, it is being powered initially by the supercap but when you feed back to the cap, you need to keep the power from flowing in the reverse direction.  I came up with this method not knowing any other way to do this without using some electronic switching mechanism which uses more energy.  So far so good but, I need more time to play with it.

Bill

[poynt99]

xee2,

Try to read what I wrote several more times until it makes sense. I think you are missing some salient points.

The beauty of the method is that it computes only the real power, no matter what the wave forms are nor what the phase relationships are.

Picture two wave forms, one above the other, synchronized in time. One is the voltage, and one is the current. Pick a number of points along the horizontal time axis and multiply the voltage and current values together at each of those points.

Now, with our method, the oscilloscope is doing precisely this but at a fixed sample rate. With the math function in the scope you multiply these two values together, then apply a running average to the result. What you end up with is a real time display of the average power.

[NickZ]

    Bill and All:
    I've been asking for this one simple proof of concept, using an AA, or cap, to test the discharge rate, so that it can also be further verified by us here as well as on other forums.  Even by those of us that don't have any test instruments. Just a cap or battery on the circuit.  I've never ever heard of any reply back, only scope shots, after scope shots, after even more scope shots. With no self runner (still presently running), to show for it all though, as yet. Hopefully this will all be verified, some time soon.