Quantum Energy Generator (QEG) Open Sourced (by HopeGirl)

[TinselKoala]

That's what I've done some years ago when testing grabriel device with a 150 $ Chinese scope, it took a couple of minutes to figure that it wasn't OU in the end. Hell, even a newbie like me (and still one) can do that...
Scope today have a lot of Math functions and are really precise, if well used difficult to fool him !

The key being the "if well used" part. It is possible to fool the most sophisticated scope by making the fundamental measurements incorrectly.

All scopes have the ability to pick up noise and/or induced voltages in their probe leads themselves. With some apparatus and signals it is actually possible to get large amplitude readings on a scope channel that is grounded at the probe tip and not actually connected to anything! Then there can be errors in the scope itself that cause spurious math and wrong interpretations. Recently some of the users of this forum tracked down a small DC offset error in a persistent claimant's oscilloscope that caused him to see false indications of overunity in his devices. This was a tiny offset error on the most sensitive input setting and it would not normally have affected anything. But making the delicate measurements and carrying them through the math resulted in pushing the device calculated performance into the "OU" region... falsely.

I myself have demonstrated two different instances where the scope's full math ability is used to go all the way from V and I measurements, through the calculation of instantaneous power curves and integrations, that falsely showed _decreasing_ energy integrals. These resulted, in one case, from badly contaminated input signals, and in the other case, from improperly time-compensated current and differential voltage probes in use (probe skew).  One on a basic LeCroy DSO and one on a high-end Tek DPSO. Garbage in, expensive garbage out.

A measurement pitfall:
http://www.youtube.com/watch?v=KWDfrzBIxoQ

[Farmhand]

Hi Tinsel, I've also have performed an apparent OU measurement on a small transformer using function generator to input a sine wave and sensed input current, measured input voltage and phase angle with a RIGOL DS1052E as well as sense the output current and measure output voltage and phase angle (in phase resistive load). I used a calculator to calculate the real (true) powers from the scope measurements. That exercise convinced me that Thanes "tiny power" BiTT OU claim was easy to reproduce.

Of course it was simply small measurement errors for the calculations of tiny power figures. I declined to video the measurement because I was certain other people would claim it was OU and I would need to keep explaining myself. It wasn't difficult to do and I, think I might know why it happens, but I'm not up for an argument over trying to explain my thoughts.

What is the effect if any of hysteresis on AC power measurements ? 

..

[TinselKoala]

What kind of hysteresis do you mean? B-H kind, where you are moving the magnetism of a core around on a per-cycle basis? I think this turns out to be a power loss mechanism; something tells me you want a really skinny "S" BH curve rather than a squarish fat one if you want to minimize losses in the core especially at high frequencies. I'm not sure about this though and I'll be happy to be educated in the matter by the magnetism experts.
I think this has an effect on the efficiency of the device under test, but measurements involving instantaneous VxI multiplication and integration of the resulting power curve should still be made normally and should still give the true result, whatever the core's BH curve looks like, I think.

[MarkE]

An ideal linear magnetics has zero hysteresis.  Apply H, get a corresponding B with no memory.

[SchubertReijiMaigo]

A measurement pitfall:
http://www.youtube.com/watch?v=KWDfrzBIxoQ

Stray inductance ? You must be really in HF for just a small wire to have a huge impact like that.
When I tested G.device I was around 50 HZ, so the frequency was to low to notice any RF effect.
Your probe are shielded ? Can it act like an antenna and make false reading ?