Is joule thief circuit gets overunity?

[profitis]

the back emf spike off any inductor is many times faster than any forward oscillation spike,how can anybody accurately assess the totality of power of this backspike?it happens so fast that it screw-hysterises any measuring meter im sure.its absolutely essential to accurately asses the total wattage of each spike to get a clear picture of totality of spikes no?possible with todays scopes?

[TinselKoala]

Not possible with Lawrence's Atten scopes, no. Possible with "today's scopes", yes, and even with yesterday's and the day before yesterday's. Believe it or not, inductors and their behaviour in circuits are actually pretty well understood, both theoretically and from a practical standpoint, and people really did do accurate and precise power measurement of circuits containing inductors, before digital oscilloscopes came along.
Interestingly, though.... for very fast rise and fall time signals the best oscilloscopes are still strictly analog, with the inputs directly driving the deflection plates of the CRT without intervening circuitry.
But you don't have to use an oscilloscope to make an accurate power determination, because you can channel all of the energy in the spikes into a resistive load which will then warm up by Joule heating. This warmup can be measured very precisely and accurately indeed, if one is serious enough. Thus you get around all sampling artefacts caused by not being able to see really highfrequency components on the DSO, at whatever sample rate/interval it uses.

[profitis]

aha @tinselkoala.calorometry yes but, like rossi calorometry,or any calorometry its vulnerable to skeptic attack due to heat losses,especialy wen we are dealing with a small COPs or whatevers left over to measure after circuitry losses.i propose a different and much more efficient way to measure with 80% efficiency and skep-proof,the electrochemical way,electrolysis of h2o,many electrolysis cells in series to swallow up the massive back-emf voltage,and subsequent evaluation of total volume oxygen produced versus consumed in the single(1.5v) NiMH cell that powers the circuit.if the ratio is larger then bang,nobody can argue results.wat u think?

[profitis]

p.s. In my above example of verifying over or underunity effects the nimh cell has to be totaly drained first then charged up with a known amount of coulombs of charge as a reference thus if you charge up with 1000 coulombs and receive 15000 coulombs worth of O2 bangbaddabing,nobody can argue overunity.the goal is to as efficently as possible store ALL of the bak-emf power and showcase it.

[ltseung888]

Now that we understand the significance of crossing the 0 ref line, I decided to go back to the old demonstration boards with an additional winding on the toroid.

Sure enough, I detected the crossing of the 0 ref line by the Output Voltage!  This gave rise to very low Output Power or even negative   However, many LEDs can be lighted brightly.  Shall investigate this more.