Ward's Build of Bob Boyce's TPU

[HumblePie]

@All,

OK I saw an MIT video about nonintuitive thinking involving Kirchoff's Law.  I need to understand why these voltages do not add up.  Nothing is leaking.  The 22M resistor has no V drop across it.  The Secondary has no V drop across it.  I am puttung HV into CW end of Secondary, diagram below is drawn incorrectly that way.

I was using the pickup coil to test using the T650-52 Secondary then various Primaries as the inductor in my 9V Battery HVPS.  I use the pickup with other lead floating.  I see reflections after the BEMF pulse at lower freq's only happen when duty cycle is < 50%, and that these are from reflections where pulse from Primary hits end of Secondary underneath and bounces around.  If Secondary shorted, all these extra humps vanish.  The positive going PWM stops the humps from continuing, and the HVPS V out snapping up to higher voltages is the event of dropping a hump into the positive going PWM region.  The BEMF pulse snaps up much higher as each hum is pushed to the right on the Scope.  It seems like the time spacing of these reflections at ends of Secondary might reveal pulse velocity in the ring.

When I was driving closed-ended 1 of 6 Prim's at 10 to 12 O Clock position (segment #6), I see pickup shows amplification at each segment going CCW like an LMD transmisison line kind of.  When I drive Prim #3 only, CCW amplifies in phase, CW amplifies 180 out of phase and amplitudes are smaller.  By 180 out of phase, I mean I see the pulses from the pickup point down Vs up as before.  When I short the Secondary out, other side of ring same polarity pulses.

When driving Prime #3 If I apply Gnd (low impedance) to CW end of Secondary, other side of ring looks same as driven side.  If Gnd applied to CCW end of Secondary, boosts amplitude of other side of ring (6 to 12 O Clock) and makes driven side also assume opposite pulse polarity (what I am calling phase incorrectly).

When I use other inductors as the HVPS I see BEMF pulse as a single pulse.  When I drive a Prim closed-emded with this HVPS, I see a triple-headed pulse.  Not when I drive the Secondary.  Stays triple-headed when Secondary is shorted out.

The scope shot shows < 50% d-cycle, and > 50% d-c shifthing the humps off to the right.  What remains after the BEMF pulse in the Red trace is ringing from the much larger BEMF.

I got 600V p-p standing waves from Prim #1 when I drove Prim #6.  The shocks feel strange.  I did not expect such voltages from only one freq into one Prim using 9V drive with no effort to drive fast transitions at all.  I was just trying to see the attributes of closed ended drive since open ended seemed so lackluster at first try.

I will try tuning open-ended tomorrow night.  If anyone can shed light on the voltage divider I see, please fill me in.  Also the link to MIT Professor explaining how this works again would be nice.  I have it somewhere in my notes.

Ward

[HumblePie]

@All,

Here is that MIT 2 part video showing Faraday, not Kirchoff's Law always holds true.  I'm still trying to put this info in terms of DCHV I am applying Vs a pulse.

http://www.youtube.com/watch?v=eqjl-qRy71w (Part 1)
http://www.youtube.com/watch?v=1bUWcy8HwpM (Part 2)

I spend many hours playing with DDS20 open-ended drive of a single Prim on my T650-52.  This was using 9V with MIC4427's Vs 15V just to see how it compares to the closed ended drive tests I did using my 9V Battery HVPS, letting Prim' be the inductor in this circuit.  I will post Scope shots later.

I see that the entire square wave applied is visible at the driven end of the Prim' tested, and that only the onther end can be made to resonate, maybe because driven end is forced so with driving signal.  The resonance is not perfect Sine wave, it more resembles triangle wave.  I think I see nodes too. 

At 3.15MHz, I see that other end (CW end) of single driven Prim resonates and so does the CW end of the Prime 180 degrees across the toroid.  Two Nodes?

At 5.4MHz, I see CW end of driven Prim resonates, and so does CW end of every other Prim.  Three Nodes?

In the Long'l Wave Research thread, the Dr's conclusions about solenoid coil's two resonant modes seems backwards to me.  It seems rather that the higher freq' resonance with shorter wave length must be the Quarter wavelength mode (3 quarters it seems)... and that the lower frequency of resonance must be Half wavelength mode per the longer wavelength.

I can not seem to find a single Quarter wavelength node yet, but I am still looking at  it.  I used a bean can as a Faraday Cage to see what would penetrate shielding.  I saw unexpected total blocking of the 5.4MHz signal.  No Longitudinal resonance.  At lower freq's, I see more clearly that the fast switching RE spikes always penetrate the shielding.  So I sweep 0 through 20MHz looking for Longitudinal resonance, but find none.  If I missed it, it is the resonance made by the RE spikes from Tr & Tf's.  This signal is so small Vs TEM signal.  Through the grounded can, I see RE peaks at 4.31MHz, 4.77Mhz, 6.45MHz, 8.45MHz.  Sinusoidal for sure, but these are clearly a mix of two frequencies and that appears to hinder a single sine wave from forming.

At first impressions, open-ended drive is nothing like closed ended drive.  How Bob sees no real difference between the two is a mystery still. 

It seems like I am going to need very high drive voltage and/or faster switching if I will achieve any effect at all.  Closed ended drive generates much higher voltages.

So while looking for the MIT video links, I found many references I'm my notes about "Flux cancellation", and I still do not see this in Bob's design... unless coils are to be driven from both ends... or as Jason does with his little green TPU on Youtube, that appears to drive two counterwound coils simultaneously.     Otto's Mobious configuration achieves this.     

Marco mentions in TP600 thread reply #25 that:  "BEMF can be captured with diodes and fed back into same bifilar coil, only other winding, so it cancels itself out... already tried this and can also capture BEMF in Capacitors."  OK so I can use it to keep electronics powered also if desired.   Bob Renip's Scope Shots of Clean Kicks" also shows a BEMF collection and rerouting of it to help drive next coil.

I have heard that we do not want bifilar, but others are using it... maybe not in Bob's design though.  I hear many things opposite of what they really are... some of this with me is just Dyslexia, some of it.  How will this unit work without flux cancellation?

Ward

[Earl]

@All,
[snip]
I will post Scope shots later.
[snip]
Ward

Ward, please include test setups and measurement points so that the scope shots make sense.

Keep at it.  There is no replacement for scratching your head nor a hot soldering iron.
We don't tackle easy things in this shop.

Earl

[Earl]

Ward,

the red/yellow versus blue/purple duty cycle variation is not what I would expect.
Try fine tuning the repetition rate as well as duty cycle change to see what difference small variations in repetition rate do to the waveform.

The three peak waveform is difficult to explain from the point of view of BEMF with exponential decay.  Each peak would have successively lower amplitude.  It looks like at least two frequencies are mixing together.

All you have to do still is to have each peak grow in amplitude.

Earl

[Bob Boyce]

@All,
<snip>
At first impressions, open-ended drive is nothing like closed ended drive.  How Bob sees no real difference between the two is a mystery still.  It seems like I am going to need very high drive voltage and/or faster switching if I will achieve any effect at all.  Closed ended drive generates much higher voltages.

So while looking for the MIT video links, I found many references I'm my notes about "Flux cancellation", and I still do not see this in Bob's design... unless coils are to be driven from both ends... or as Jason does with his little green TPU on Youtube, that appears to drive two counterwound coils simultaneously.     Otto's Mobious configuration achieves this.     

Marco mentions in TP600 thread reply #25 that:  "BEMF can be captured with diodes and fed back into same bifilar coil, only other winding, so it cancels itself out... already tried this and can also capture BEMF in Capacitors."  OK so I can use it to keep electronics powered also if desired.   Bob Renip's Scope Shots of Clean Kicks" also shows a BEMF collection and rerouting of it to help drive next coil.

I have heard that we do not want bifilar, but others are using it... maybe not in Bob's design though.  I hear many things opposite of what they really are... some of this with me is just Dyslexia, some of it.  How will this unit work without flux cancellation?

Ward

Very good experimentation Ward. Good to see you are noting some of the oddities in multiphase coils on a single toroidal core. It looks like you have also noted that the responses are directional in relation to drive coil polarity and direction of rotation. It is the direction of wind and direction of applied drive pulses that cause this as the shock wave propagates down each primary when pulsed. And yes, the intent of the 2 sets of 3 phase primaries is so that you can drive the 180 degree opposing primaries in phased pairs for even more result. Sort of like a multi-pole 3 phase motor.

I never said that driving open ended was the same as closed loop. All I said was that the same effects could be observed, but obviously the drive requirement method for open ended is much different. Open ended drive still requires very vast transitions, but applied potential (voltage) must be a lot higher to get the same effect. Whereas closed loop works at much lower voltages, but is more critical to pulse width if power waste is to be kept to a minimum. Transition times are key in both drive modes, as it is the transition that creates the desired shock wave that will appear on other windings as "kicks".

What you will want to do it to adjust the timing of the applied pulses so that these "kicks" become additive. You will find this occurs in multiple points with varying numbers of nodes as timing interval is decreased (apparent frequency increased). When you add the other subharmonic drive channels, you will begin to see patterns develop in the common output as viewed on your pickup probe. You will not get the same effect from a single pulse source.

Bob