Kapanadze Cousin - DALLY FREE ENERGY

[Meta]

Verpies and AlienGrey cant stand me telling how to do it, first. Later, after they have maligned, me, they will claim they have discovered the same thing, first, with no reference to me.

[kolbacict]

Boonk,is this your picture?
What happen to a cite cyberenergy?

[apecore]

It is not acceptable because you clearly have spikes (marked in red) above typical V_{GS_th} (marked in yellow) which results in spurious MOSFET turn-ons.
The -4.8V negative excursions are not a problem (marked in green).

P.S.
Lookup in the datasheet what the V_{GS_TH} parameter is for your MOSFETs.

Verpies,
Your right thanks, i didn't notice those red ones

The Vth = 2    -    4V.           ....so those peaks let the mosfet switch. (IRFP260M)
I ll see that i have several short peaks of (5 total) of 250ns,..... vew of them are 4V.
the fet with the longest wire to gate has the highest peaks.(wich are also present but stay around 2 V, some even 2,2V)
Unfortenatly the Treshold voltage of 2,2V at 250ns would also trigger the fet,... or is it to fast in order not being able to charge the gate sufficient?

I consider placing the mosfetdrivers as close as possible to the mosfets will give most positive effect on the spike elimination.
Or is there another simple way for elimination?

[verpies]

Unfortunately the Threshold voltage of 2,2V at 250ns would also trigger the FET,... or is it to fast in order not being able to charge the gate sufficient?

The Turn-On Delay time is 17ns for this MOSFET and the Rise Time is 60ns (with 10V gate pulse and 1.8Ω gate resistor) so 250ns is plenty enough to turn-on this MOSFET, but in reality the current in that spike is probably not sufficient to fully turn it on.  However a halfway turned on MOSFET is not happy either because its Source-Drain resistance becomes several Ohms and leads to Joule heating according to i²R.

I consider placing the MOSFET drivers as close as possible to the MOSFETs will give most positive effect on the spike elimination.
Or is there another simple way for elimination?

Gluing the drivers to the MOSFETs will help a lot, but you must also shield the high-impedance inputs of the drivers with a twisted pair or mini-coax.  The drivers should have low ESR (non-electrolytic) capacitors soldered right across their supply pins, too.  Ferrite beads or mini-chokes are recommended too, before these capacitors.
As usual, shielding, short wires and Starpoint grounding are a must, too.

Also, you might want to use other techniques described in the attachment below.

[verpies]

I updated the PDF attachment above.  So just download it again.