Successful TPU-ECD replication !

[z_p_e]

@ Earl

SM suggested in his posts, to build a "mini tube amp" using Mosfets, to power the TPU, to start with.  He said it would be faster all around, to see something happen.  Can you explain as an electronic guy, how close to what is being done, is to a mini tube amp?  Is there any similarites?  What would the difference be?

I think this is an important post of SM's.

Thank you,
Bruce

Bruce,

What everyone has been doing to date (excluding Lindsay perhaps) with their MOSFETs is not a mini tube amp.

Tube amplifier (or any amplifier) implies amplification, in the linear sense. MOSFETs used as switches are being used in a nonlinear sense.

SM used 3 tube oscillators to begin with, and this leaves open either sines or squares.

I believe the majority (including myself) lean towards square waves, or more precisely, pulses. Tubes can be used as switches also, but what exactly Steven meant by mini tube amp is for you to decide.

If he really meant amplifier, then we should be designing a MOSFET amplifier based on the old tube amp designs.

If he meant tube amp in the nonlinear sense, then we should be building tube switches.

Darren

[hartiberlin]

Earl,
you are right,
we want very fast  switching time.
So what kind of driver NPN and PNP transistors would you suggest ?
Is it best to use SMD types and hook and solder them directly
to the IRF 840 pins ?
Maybe we can then can just build this into the TPU.
Do we really need aluminium heat sinks if we just switch on
and off very fast ?
Then the IRF 840 MOSFETs should not get very hot at all, right ?

What about freewheel diodes across the controller coils ?
Are there any ? Have to study again the PDF file from Otto and Roberto.

Regards, Stefan.

[Freezer]

Is the wiring in the right orientation?  Im gonna try and model this thing for better a visual.

[maxc]

Hi all ,
I've  tried zener diodes across the gate, ran off a coil to fire off the befm of the control coil. NO way to control the frequency (2.5MHZ) If i was reading the scope right(it's old) 6 volt rise in  .25ns

Mark

[hartiberlin]

@Freezer,
looks very nicely,
but I guess the 2 pairs of dark yellow wires should be over each other, so
not horizontal beneath each other...if that matters ?
I just had another closer look at Otto and Roberto?s PDF file.
It seems the Phase and Zero line where the bulb is connected works
like a transmission line as it is itsself shorted out already by the moebius
coil setup.

I wonder what would happen, if we rather put into the shortout the bulb, than
to use a transmission line tapping of the moebius setup ?

Also I still don?t understand the meaning of using in each Control Coil 2 windings ?
What is the advantage of this ?

Regards, Stefan.
P.S. I see no freewheel diodes in all the circuit diagramms, so I wonder if the
freewheel diode inside the IRF 840 play any role in it and this "anomalous avalanche" mode ?