Eldarion and Bruce's build of Bob's Energy Converter

[eldarion]

Hi Bob,

Sorry I took so long to get back to you; one of my primary servers crashed Friday night and I spent all of Saturday repairing the hardware and reinstalling the OS.

The channels are:
Channel 1 (top trace):       F3 (lowest frequency)
Channel 2 (middle trace):  F2
Channel 3 (bottom trace):  F1 (highest frequency)

So for Rich's setup, is this the schematic?:
http://www.falconir.com/pics/secondary_connection_style2.jpg

What size DC blocking capacitor should I be using?  Right now I am using a 0.68uF 160V polyester cap, which at an F3 of 10KHz works out to 23.4 ohms of reactance, and at the corresponding F1 of 40KHz it works out to 5.9 ohms of reactance.

In case I haven't already mentioned these specs, here they are:
IGBT source voltage: 13.8VDC
HVDC potential voltage: 160VPDC, pulsed at 60Hz
No magnetic bias is connected
Secondary of transformer in series with 160V HVDC supply for HF filtering
7W 120V light bulb used for testing purposes

I tried firing up the system with all of the above specs, and preliminary results are still null; COP < 1 though higher than before (lights bulb to full brightness on 11.04W of input power, HVDC still has no effect).  Any thoughts?

Thanks!

Eldarion

[Bruce_TPU]

In case I haven't already mentioned these specs, here they are:
IGBT source voltage: 13.8VDC
HVDC potential voltage: 160VPDC, pulsed at 60Hz
No magnetic bias is connected
Secondary of transformer in series with 160V HVDC supply for HF filtering
7W 120V light bulb used for testing purposes

I tried firing up the system with all of the above specs, and preliminary results are still null; COP < 1 though higher than before (lights bulb to full brightness on 11.04W of input power, HVDC still has no effect).  Any thoughts?

Thanks!

Eldarion

Hi Eldarion,

A quick question my friend.  Why "no magnetic bias"?     I do not think OU is possible without that also hooked up, from what Bob has said.  Bob, please correct me if incorrect.

Quote about the magnetic bias from the .PDF:  (For everyones learning)
"The one that has a separate DC bias winding can introduce a much greater angular field, but it can be quite the beast to control. This one is like a hurricane that can turn into a tornado at a moments notice. This is one that can initiate intense lightning strikes and other nasty stuff if not kept on a VERY tight leash. Obviously, this one is not shared with the hydroxy gas crowd.

The riskier and higher performance toroidal power system uses both the DC potential bias and a magnetic bias."


AND

"Vortex mode, which is almost identical to rotational mode. The addition of a longitudinal bias winding and a high enough DC bias can result in the analogy of a "severe hurricane", or a "tornado". This is the highest energy mode, which is very unstable, and can be extremely difficult to maintain control of.

Applied bias can play a major role in the behavior and severity of the "storm".

Oh, by the way, that longitudinal low voltage bias winding is for adding the magnetic bias, not a low voltage DC potential bias, so it must be a fully closed winding fed with straight DC, not pulses. That longitudinal winding is to be wound in the direction of rotation, from top to bottom. The higher voltage DC potential bias needs to be coupled onto the secondary, and decoupled from the load for most applications. If longitudinal DC is required to run a load, then you can add another longitudinal winding or two to the top and/or bottom of the core before wrapping the secondary. Be sure to follow the direction of rotation or it will not work properly."

Warm regards, 
Bruce

[eldarion]

In case I haven't already mentioned these specs, here they are:
IGBT source voltage: 13.8VDC
HVDC potential voltage: 160VPDC, pulsed at 60Hz
No magnetic bias is connected
Secondary of transformer in series with 160V HVDC supply for HF filtering
7W 120V light bulb used for testing purposes

I tried firing up the system with all of the above specs, and preliminary results are still null; COP < 1 though higher than before (lights bulb to full brightness on 11.04W of input power, HVDC still has no effect).  Any thoughts?

Thanks!

Eldarion

Hi Eldarion,

A quick question my friend.  Why "no magnetic bias"?   

Hi Bruce,

I was under the impression that the magnetic bias windings were there to shut down an unstable vortex if it were to form, and that therefore having a constant magnetic bias would lessen the generated power.  Now going back and re-reading the PDF; you may be correct and I may be incorrect, but I would like to hear Bob's take on it before I test the converter again.

Hmmm...Bob, can you verify that the required power into the magnetic bias coil is only a few hundred milliamps?

EDIT: I have been thinking about the sharp, narrow pulse requirement.  Are we trying to approximate a Dirac delta function here in an effort to inject an infinite number of frequencies into that primary coil?  If so, how does this work with the rotational mode?

EDIT2: I have also been looking over your PWM3E circuit, and I was wondering why you included R4 and R7 on the gate of Q1?  It almost looks like there will be an asymmetry in turn off / turn on times, with the device turning on slowly and turning off quickly, although not nearly as fast as if you had just coupled Q1's gate directly to the PCP116 optocoupler.  Maybe this slowing down of the switching is eliminating any possible ringing problems, like the ones that I am having in my controller?
Looks like this is fixed in the PWM3F system--sorry!

EDIT3: I promise, this is the last edit!   I decided to run some simulations to test an idea I had, and the results seem to strongly back it up: the load impedance is critical!  Too high, and you will get terrible primary ringing.  Here are two simulations, one with the rough equivalent impedance of a 7W 120V light bulb (in reality the impedance is even higher), and one with a 100-ohm load (about 150W @ 120V).  Notice the absence of ringing with a low output resistance!
High output resistance waveforms and test circuit: http://www.falconir.com/pics/high_load_resistance.jpg
Low output resistance: http://www.falconir.com/pics/low_load_resistance.jpg

Eldarion

[eldarion]

After running a ton of simulations and reading up on the operation of flyback converters, etc. I have figured out that the ringing on the primaries (or lack thereof!) is highly dependent on the winding inductances, coupling between primary and secondary, and the load impedance.  Mess up just one of those values, and terrible ringing will result, along with almost zero power transfer to the load (exactly what I am experiencing on the test bench).  Coupling must be as close to 1 as possible.  Interestingly, the ringing is not dependent on frequency or pulse width--this is also a very good thing as far as control devices are concerned.

What I am going to do is obtain an inductance meter so that I can not only measure primary/secondary winding inductances and choose a proper load impedance to reduce ringing, but so that I can also measure the transformer's K.  My simulations show that the primary ringing can be completely eliminated if the load impedance is chosen properly and the K is high enough, > 0.95.

This is probably why the switching power supply Bob had talked about as the origin of this effect only went into overunity operation under "certain load conditions".  With a specific loading impedance, the effect-destroying ringing would disappear, and if the controller then delivered the correct pulse sequence for an instant...  Also I would surmise that the K would be quite high in a mil-spec high-efficiency switcher.

It may be quite a challenge to create a controller that will maintain a specific load impedance into the coil under highly variable output loading.  Something to think about, anyway!

Pushing forward...

Eldarion

EDIT: I have now run some tests on the coil, and can confirm that when driving only three of the six primaries the leakage inductance on each pimary is quite high--high enough that I cannot even come close to eliminating the ringing in that configuration.  Also, as a result, the K is probably quite low, which is probably why the best efficiencies I have seen are only in the 40-50% range.  A "normally" wound (not sector wound, as this one is) toroid driven that same way should have an efficiency of 95% or better! 

I wonder if the primary coils' leakage is supposed to be that high or not?  We deviated from the original hydroxy design when we wound 6 primaries instead of three...

[Bruce_TPU]

Hi Eldarion,

That is a great bit of electronic detective work, and should help out the guys with their build.

I wonder if the "magnetic bias" will effect the ringing problem.

The magnetic bias is a quarter of the four main components of Bob's device.  And without that in the mix, no other solutions can be established.  For if you do, they will each have to be re examined when you add the non pulsed dc magnetic bias to that longitudinal (solenoid) winding.

The four main components, of which, if any are missing, is an incomplete, non working device:
1.  Properly wound coil
2.  Magnetic bias of non pulsed 13.5 vdc minimum for over unity to occur.
3.  Secondary HV dc potential of 160 vdc minimum
4.  Primaries pulsed with the proper frequencies, and timing pattern with clear waveforms.

I realize this is simplified, but not to "harp", 25% of the device is "missing" without the magnetic bias hooked up.  That will effect everything in ways the simulator can not see.    

Warm regards,
Bruce