Understanding electricity in the TPU.

[wattsup]

Something else really weird happened during this weekend of testing. Since I am only blowing those PN4416s (12 blown so far but I will stop), I decided to do some other tests with my toroid that has the dual primary over my dual secondaries.

I tried this both in standard bucking or in @gotolucs mode the effect happens the same. I wanted to see what would happen if I cut the power to the toroid from both ends at the same time. So..........

I put the positive of my power supply to the drain of an IRF9540 PNP mosfet and sent the source to one side of the primary. The other end of the primary went to the source of an IRF840 NPN mosfet and the drain went to the power supply ground. Both gates were in parallel and connected to only the positive of my pulse generator. The secondary which was also either in bucking or @gotolucs mode were connected to my capacitor tank via a 1N5817 high speed diode. I put my LED bank on the cap and my volt meter.

I put the power supply at 5 volts and set the pulse generator to 16.5 volts. When I got to a resonance of around 3mhz, the LED lit up supper brightly, the amps on the power supply read like .01 to 0. The FG amps was again micro amps. But the DC voltage meter on the cap tank read 0 volts. WTF is going on here. I was totally puzzled as to why it read 0 volts since this is the first time that has happened. Then I put the capacitor volt meter on AC and it read 9 volts.

So the toroid primary pulsed from both ends is producing strictly AC. Enough so that I changed the LED for a small 130 volt 11 watts rated bulb and the filament lit up semi-bright, something I could never do before. I wonder if this is enough to light up a vacuum tube cathode. I think so.........

I was always wondering what SM said about the AC in his devices. Where the hell could an AC come from in a DC pulsed device. Now I see it could come from the center toroid in bucking mode when pulsed from both ends. I cannot explain technically why it is doing that but it does. I tried at lower frequencies and to my amazement it still worked from 2khz to 10khz as if it had a large bandwidth there that kept the effect going.

I will have to document this more precisely during the week.

[e2matrix]

wattsup, sounds like some interesting results.  It's somewhat hard to tell what's going on voltage wise even with the AC setting if the frequency is too high for the DVM and most of them don't go that high.  Did you look at this with your scope?  It looks though like you have an effect to dig deeper into.  Good work!  I'll have to leave it to some of the smarter ones here though for a possible explanation.

[forest]

well, isn't pure LC resonant wave an AC wave ?

[gyulasun]

...
I put the positive of my power supply to the drain of an IRF9540 PNP mosfet and sent the source to one side of the primary. The other end of the primary went to the source of an IRF840 NPN mosfet and the drain went to the power supply ground. Both gates were in parallel and connected to only the positive of my pulse generator. The secondary which was also either in bucking or @gotolucs mode were connected to my capacitor tank via a 1N5817 high speed diode. I put my LED bank on the cap and my volt meter.

I put the power supply at 5 volts and set the pulse generator to 16.5 volts. When I got to a resonance of around 3mhz, the LED lit up supper brightly, the amps on the power supply read like .01 to 0. The FG amps was again micro amps. But the DC voltage meter on the cap tank read 0 volts. WTF is going on here. I was totally puzzled as to why it read 0 volts since this is the first time that has happened. Then I put the capacitor volt meter on AC and it read 9 volts.

So the toroid primary pulsed from both ends is producing strictly AC. Enough so that I changed the LED for a small 130 volt 11 watts rated bulb and the filament lit up semi-bright, something I could never do before. I wonder if this is enough to light up a vacuum tube cathode. I think so.........

I was always wondering what SM said about the AC in his devices. Where the hell could an AC come from in a DC pulsed device. Now I see it could come from the center toroid in bucking mode when pulsed from both ends. I cannot explain technically why it is doing that but it does. I tried at lower frequencies and to my amazement it still worked from 2khz to 10khz as if it had a large bandwidth there that kept the effect going.

I will have to document this more precisely during the week.

Hi wattsup,

If I understand correctly your circuit description, I would suggest to replace the p channel MOSFET drain with its source electrode ( its source electrode ought to connect to supply positive) and also replace the n channel MOSFET drain with its source electrode (its source electrode ought to connect to the supply negative), ok?  And repeat the test.  Maybe you will find the same behavior as before but then the FETs would receive correct DC polarities.  Please double check your setup with respect to your above circuit description, I can reflect on only what you describe.
(A p channel MOSFET must get negative supply voltage at its drain electrode with respect to its source, an n channel must get positive voltage  at its drain with respect to its source.) 

If you achieved resonance in the secondary then you must have some form of AC voltages in that LC circuit developed, don't you? (At resonance, an LC circuit always tries oscillate in sinusoidal form, even when excited with pulses;   forest also refers to it.)

Did you connect the pulse gen negative to the supply negative too?

rgds,  Gyula

[giantkiller]

@wattsup,
This is schematic of a test you just did.
Muy Importante!

The gates can be fired together or by 2 different pulse sources.