Kapanadze Cousin - DALLY FREE ENERGY

[Dog-One]

   I checked about the location of the scope. The Costa Rican postal service says that they have not received it yet.
And that it can take 2 to 4 weeks to arrive.  So, I'll check back with them, in a week or so, now that I have their number.
   The package may be taking it's time, but possibly is not lost in the mail, as yet.

Keeping my fingers crossed.  I'm pretty sure this will help you a lot
to gauge where your push/pull driver is needing attention.

I'll also swing by the postal annex and let them know their 10 business
day estimation was way off.  Maybe they will be able to run a trace
on the shipment and get someone's attention to wake up and get
this package on the move.  Can't hurt.

[NickZ]

  Itsu:
  I find that a single blue 103 2kv HVcap on the left Fet brings it right down to 500KHz. Down by 1/2 from 1.08MHz, with no cap on.
The right fet using the same 103 cap, goes down to 444KHz. Is that close enough, or not.
The left fet was showing 4div, at .5us.  The right fet was 4.5div at 0.5us setting.
  Running on 12v battery with only 9.2v on it, with a 100w bulb load barely lighting.  200 plus volt spikes.

[NickZ]

   Dog-One:
   Good to see that you're reading these posts.
   Checking on the scopes location would be great, if you can.
  I did what I could for now, on my end.

   How are you coming with your version of Nelson's device?

[itsu]

Nick,

a 103 (10nF) cap looks rather big to me, but it is what it is.
So the parasitic capacitance that is causing that ringing suppose to be 1/3th of that 10nF, so 3.3nF.
Right away we can determine the final caps value as it should be 4 to 10 times this 3.3nF, so you can start looking
for suitable ceramic caps inbetween 15 to 33nF (600V or so).


The parasitic inductance calculated with step 3 of the procedure (or via this website: http://www.1728.org/resfreq.htm) is
L = 1 / [(2 x 3.14 x 1.08MHz)² * 3.3nF] = 6.6µH

The resulting characteristic impedance (step 4) will be  (or via http://ncalculators.com/electrical/transmission-line-characteristic-impedance-calculator.htm)
Z = SQRT (6.6µH / 3.3nF) = 45 Ohm


Meaning you will need to build a RC snubber consisting of a 45 Ohm resistor and a 15-33nF capacitor in series.
Place the RC with the free resistor side to the drain and with the free capacitor side to the source.
Use as short as possible leads.

Your ringing should be gone almost, but beware of the single spike that still will exist, so use the low voltage first.

Make screenshots and we will be taking it from there.

Regards Itsu

[NickZ]

   Itsu: sounds like two 103M 2000v blue caps in parallel, for a total of 20 nf, and the 45 ohm resistor should do.   
   I guess the resistor should be like two watts size?
   I'll look for some of those parts.