Steven Mark`s TPU

[ronotte]

Wattsup,

I can't resist giving you THE ANSWER:

I WILL JUST USE MY ECD V2 TO DRIVE TPU V10-7 - THAT'S ALL.

Perhaps Saturday with the help of Gustav22 I'll try that!!!!

Thanks a lot for your suggestions. I'll keep you well informed.

Roberto

[Carl.]

@Wattsup,

Why not try a variation of the Dr Stiffler Circuit, check out the thread Selfrunning cold electricity circuit from Dr.Stiffler under the magnet coil setups. He is getting HV using a simple ferrite bar. Could this be what SM is doing with the small torrid in his deisgns? using a simple oscillator to step up a 9vdc source?

[ronotte]

Hi all,

yesterday evening I partially solved the puzzle about my TPU V10-7 AUTO-OSCILLATION mode.

After some scope probing I found that only the middle power Mosfet was trickled into operation: all the others found OFF, don't ask me why as I don't know...at least for the moment. Of course capacitance feedback to Gate is the answer: but why not for the other 2 Mosfets?

The pic attached does show  (in upper trace) the input signal found on Gate and (in lower trace) the corresponding Drain signal  - ALL STABLE - and self explaining (ground level for upper trace is 1 div over the screen centre, zero level for lower trace is 1 div over the screen bottom). Main freq is 22.22KHz, smaller sinus freq are about 200KHz.

Roberto

[Earl]

Roberto,

on all transformer secondaries insert one lossy ferrite bead in series to the gate, and see what effect that has?

-OR-

You might also connect a resistor between gates and sources of X Ohms to lower Q of transformer windings.  In other words, in parallel with the secondary, but directly at the FET with very short leads or use SMD chip.

The pulse transformers may or may not be self-shielding.  The only self-shielding transformers that I know are pot cores.

Regards, Earl

[ronotte]

@Earl,

Thanks, of course I did not put beads as the pulse XFM used are pot-cores. The funny thing is that only one of the absolutely equal other two does show said effect.

Roberto