Could have sworn I did in my original post but here it is:
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From authors comments
here I am not sure I understand why he needs up to 9A flowing through the gate drive transformer primary - he talks of increasing the value of C6 to improve gate transformer performance. As I understand it increasing the value of C6 decreases the impedance at a given frequency and inductance and therefore increases the current.
But FETs are voltage operated devices so why would you need amps flowing through the gate drive transformer secondaries, and into the FET gates, as opposed to milliamps?
I am also using IXTK 62N25 as my FETs but even so surely you don't need amps to charge the gates of these quickly?
I hacked up a heat sink for my ucc27425 pdips. I have a draw full of heat sinks I removed from tv circuit boards. I just got one of the medium size ones, with flat sides, that they use for the smaller power transistors. It was long enough to span both pdips and I have cable tied it down using a couple of magnet wire loops I made in my matrix board.
I have also done the pulse generator part of the circuit differently.
1) I have setup a opamp based x10 audio amplifier.
2) An XR 2209 triangle wave generator.
3) A comparator.
And I am using to feed in PWM'ed audio into my gate drive transformer.
Also an astable 555 to feed in a normal square wave and a switch to chose between the two.