Auroratek demonstration from Bill Alek at TeslaTech conference

[tinman]

@TinMan.... Alternating DC.... yah, that will be very helpful. Let me ask you something: Have I helped you at all in your understanding of oscilloscopes and their use? Have I led you wrong in any way, so far? Would YOU accept data from an AC-coupled scope in the situations I have described above?


Just for amusement purposes only:
http://www.youtube.com/watch?v=Frp03muquAo
http://www.youtube.com/watch?v=Pr3Olkd_5EI

Indeed you have been very helpful TK,and no,i wouldnt use AC coupling on the scope,as you will see in all my scope video's.
Now,how about a neon rectifier-just a little something i was playing with over a year ago-back in the days of the CRT,and my youthful scope talk lol.Just thought i would post it,as there was some talk of neons.

https://www.youtube.com/watch?v=wY97yCxU_OI&list=UUsLiBC2cL5GsZGLcj2rm-4w

[TinselKoala]

That was a very nice and thorough demonstration. You answered all the questions and addressed all the issues that came up in my mind during the demo. I've used neons since forever to check field shapes, polarities, spark gaps, limiters, voltage regulators, all the rest... even as power indicator lamps, actually! But I never thought to use them as actual pickups or converters like you do there. Neat idea, and something I'll be trying myself with the miniSlayer after breakfast.  I think I know what's going on... a common theme is running through a lot of different threads here lately. Who needs huge mercury plasma rectifier tubes when you've got Neons!

You should check out this man's work, it is amazing. Not that it actually is related to what you are showing, just that it shows some possibilities of tuned circuits.
https://www.youtube.com/channel/UCNAAxVKWPAbaZiB90_kjDJw

[TheCell]

If the output from the amplifier is coupled by a capacitor (in most cases it is, cause you don't want a bias dc current through your load ; for example a speaker box) what's wrong with measuring  input power having a ac - coupling setting in the scope. The ac frequency in the kHz-Range, that's way beyond the cut-off frequency of the scope. A scope can render mains frequency with no problem using AC-coupling .
If you lower the   amplifiers frequency under the cut off freq. of the scope the internal cap in the scope attenuates the signal, but with a frequency in the khz Range this effect is negligable.
A leakage current from the secondary to the primary due to bad insulation results in additional power consumption on the meter.
In fact in the kHz Range there could be a inductive component in the Load Resistor , but Bill says there were no phase shift . So it's our choice to believe him or not.

[MarkE]

Mark,

As I pointed out, the saturable reactor circuit is a close approximation of the first half of Alek's circuit--and by no means did I imply it was exactly the same to its entirety. As for my results, they demonstrate that coupling between secondary windings placed on isolated cores to a commonly wound primary winding can be very high. Nothing you've said refutes this. I want to point out that I didn't claim my circuit was exactly the same, only that certain elements are very similar.

The logical fallacy is that because some thing A can have a characteristic that we should infer that some other thing B also has this characteristic.  It is an invalid inference.  I have pointed out the real physical differences between your set-up and Bill Alek's.  I have suggested a test you can perform by altering your set-up to try and further your argument.

I agree that his transformer would have a worse k factor than my circuit due to reasons I've already stated as well as the ones you have pointed out. We both agree that his exact arrangement will give a less than satisfactory k value. What we don't agree on is the exact amount of coupling physically possible.

What matters is what he has in-hand.  A different arrangement should lead to different measurements.

Obviously we both have our own experience and assumptions to support our arguments. Therefore, both of us need to prove our point more conclusively, either using a 3rd party authority (e.g. a texbook) or physical experiment.

I have proposed an experiment that you can try with your materials.

[MarkE]

as I said it is probably not an important issue _in this case_ as far as the measurements per se go, but it indicates a certain non-expertise in measurement and scope use, which is why I would like to see the question posed just as I have presented it. Here we often deal with claims of OU that are close to the noise floor, and cases of  OU indications have been tracked down to improper use of channel coupling. This is a very easy way for someone to inject lots of power into an input if they want to be deliberately  misleading, or to deliberately under-read an output power. Whenever I see AC coupling used for anything other than examining small signals on top of large known DC offsets, I want to know exactly why the channel is coupled that way, and I want to know that it does not affect the math that is performed on the traces.
It has even come to my attention that some qualified professionals don't even know what AC actually _is_. The NI white paper is an example. The writer refers to a sinus signal that is 100 percent above baseline as "AC". It isn't, though. It is a fluctuating level of current that always flows in the same direction. It does not become AC until there is current reversal happening, and this will not happen until the voltage signal actually does dip below the zero baseline and become negative at the measurement point. IOW, if the DC offset is _greater_ than the amplitude of the ripple, you don't have any AC at all because the current does not alternate, it simply rises and falls in magnitude in the same direction. It is only correct to speak of "AC with DC offset" when the offset is smaller than the ripple and zero-crossing actually happens.
This is overly pedantic and I generally know what people mean when they speak about AC with DC offset, etc. but it's easy to prove what I'm saying, if you don't believe or agree, with an LED, the scope, and an FG that has adjustable offset and can put out a 1 Hz sine wave. You can display the same sinus signal and have the LED on 100 percent of the time, off 100 percent of the time, or anywhere in between depending on the DC offset setting of the FG. LED on 100 percent of the time: NO ac! And if the scope is AC-coupled the signal will look exactly the same _vertically_ and appear as the identical AC signal no matter whether the LED is on 100 percent, off 100 percent or anything in between. You will be able to report and demonstrate all kinds of strange behavior if you just keep your scope on AC-coupled.

That is exactly  my point wrt the scope but I don't know about the meters. DC offsets could be contributing to the actual power IN without being measured on the scope. However I think they would show up on the output DMMs, being included in their math. This is an interesting issue and I don't know the answer wrt the DMMs. I wonder if Poynt99 or MarkE can speak to this issue.

ETA: both of Alek's output DMMs are Flukes, one is a 187 TRMS I believe and the other is more modern but also, I believe, a TRMS meter, possibly a 175. I refer you to page 3-4 in the manual:
http://assets.fluke.com/manuals/187_189_umeng0200.pdf

If it works... it's a FLUKE!

(also... we know that a ripply DC signal applied to a primary of a transformer will, unless the core is saturated by the DC, produce an AC output in the secondary, with an amplitude that is determined by the p-p amplitude of the original ripple on the DC input. Right?)

MetGlas cores have very square BH curves and high permeability that make them suitable for use as magnetic amplifiers.  The oscilloscope waveforms do not show obvious distortion that would result from saturation so I do not think that DC bias is a concern.  The operating frequency of 3kHz is far above the AC cut-off frequency for the scope probes and therefore should not contribute much phase shift at all.