Auroratek demonstration from Bill Alek at TeslaTech conference

[mscoffman]

Metglass Cores;

I noticed that none other then J. Robitelli of QEG fame, his store seems to be selling Metglass Inc. AMCC 320
Metglass cores. These cores were made famous in the Tom Bearden's MEG affair. These advanced technology
cores were then selling for $$$ in those years. Note, that there are no prices listed and I believe however
they were used they probably still retain their magic material specs. That high voltage insulation coil wire
looks good too.

As usual; Buyer Beware, especially in this case.

Web Link:

http://teslaenergysolutionsllc.com/store/


:S:MarkSCoffman

[MarkE]

Mark,

The secondary magnetic circuit is a COMMON MODE choke, meaning it doesn't contain differential mode inductance!

A CM choke is just a transformer. If the K factor is high, then the effective inductance seen by each side is twice that of either single winding in isolation.  Bill Alek's windings have low coupling coefficients:  K

That is, the magnetic fields of each winding null out to leakage levels. Assuming I understand how both common mode chokes work and Alek's circuit, your point about k<<1 might be off.

I think that you don't understand them well.  The idea is that the reactance of the magnetizing inductance in each winding is much greater than the impedance of the external circuit.  Current impressed from the dot end towards the non-dot end of one winding induces a voltage across the other winding that will ideally result in a matching current from the non-dot end towards the dot end of that second winding.  In a perfect world this results in nearly equal currents flowing in opposite directions, reducing the net common current in one direction or the other out of the choke to be very small compared to the original individual currents.  A common mode choke that has a low K factor performs badly.

Of course it will be lower than a normal transformer because his windings do not completely enclose the primary core section--there is open space. BTW I've built magamps that use very similar construction to Alek's transformer and achieved rather high coupling coefficients. If you want I can take some pics and post the measurement results.'

I always like to see interesting data.

Also, your point about the coupling coefficient is wrong, in the sense that regardless of its value, the load impedance is reflected back to the primary. Thus primary inductance MUST decrease when the secondary is loaded, thereby lowering the primary impedance and appearing more resistive--however slightly this may be due to weak coupling. Why Alek's transformer does the opposite is the real question.

Take an ideal transformer and drive an inductive load.  The inductive load reactance reflects right back at the primary.  Shorting the secondary of a transformer with a low K has the same effect:  the leakage inductance becomes the load.  In a weakly coupled transformer, the primary current phase shift gets very close to 90 degrees for either condition:  open or shorted secondary.  Low phase shift is possible with a tightly coupled transformer such that the magnetizing reactance is much greater than the load plus winding resistance and the leakage inductance reactance is much lower than the load resistance. 

Bill Alek's windings are labelled:  120mH / 122mH for the secondaries, and 3.07mH for the primary.  Let's assume that those values were obtained with an LCR bridge one winding at a time with each of the other two windings open.  Using K values of 0.8 and loading with 0.01 Ohms, the phase shift at 3kHz in the primary is 84.6 degrees.  Loading with 1E9 Ohms (open) the phase shift is 88.6 degrees. Up the K to 0.99 and the 0.01 Ohm condition gets much better due to the winding resistance: 28.2 degrees phase shift, while the open circuit case remains unaffected.

I think that what we see is just a combination of weak coupling and poorly conducted measurements.  That seems to be the legacy of over unity transformer claims.

[MileHigh]

Look at this:

https://www.youtube.com/watch?v=ddj85px00lM&list=UULuDKTNDFfat7iO7KGE7fQA

Russ was there!

Quote Russ:

ok, well there is nothing new here if you ask me, this has been demonstrated in the past in different ways.

but looks fun to play with..

note @ 42:00 i ask the right question and the answer was " im probably just a few weeks away from finishing it" how Manny time have i heard that...

I am pretty sure the question Russ posed at 42 minutes was about the magic bike!  I was dead tired when I watched it, perhaps someone can confirm.

Bill backpedaled!   Ouch!  lol

MileHigh

[MileHigh]

And not a single response from Mr. Drive-by-Shooter Acca.

[G4RR3ττ]

Well Mark you can have high coupling factor indeed!

But first I want to point out, measuring magnetic circuits employing ferrite is a b*tch: changes in temp, slight mechanical shock and differing drive level (changes in applied H-field due to changes in number of turns) add much experimental error.

Now on to my little saturable reactor / magamp. Note that, for this circuit, tight coupling was intended for experiments exploring parametric variation (such as frequency conversion and AM modulation of an RF carrier). The tighter the coupling the less control winding current is needed to cause a change of inductance in the anti-series connected secondary circuit. Fundamentally the circuit is a variable load inductance programmed by a voltage controlled current source. All that said, the magnetic circuit closely resembles the primary half of Alek's transformer. At a later date, I'll put up some measurements of a full equivalent circuit, when I can find a CM choke to use for the other half of his secondary arrangement.

What's interesting about this circuit is that the primary winding is shared across two separate and isolated cores, which is exactly how Alek's primary circuit is wound. The only major difference is that of winding style and obviously the lack of the CM secondary arrangement--which I still feel doesn't contribute to large secondary inductance as you propose.

On to the measurements and Pics. First I want to say that both methods of determining k (shorted secondary and measured mutual inductance) were undertaken with the utmost care, all values are derived from measurement and not calculation, unless required. As is generally know to be the case, the mutual inductance method gives erroneous values, this is due to the greater number of ampere-turns that excite the core which shifts the incremental permeability to differing values, in this case greater u_i. Thus k is calculated as being greater than one, which is an invalid result. The arguably better shorted secondary test gives a a very high coupling coefficient of 0.99879.

Concluding, I think we can safely say his primary circuit isn't a major contributor of leakage inductance. However, large leakage in the secondary extraneous circuit is still on for debate. I'm thinking it's not going to be very large though, seeing as how the split secondary fields oppose one another and have the same turns ratio, they will likely have very low (possibly <200uH) leakage inductance.