Tonny, if you put the oscilloscope across the leads of the primary you should see the pulse incoming than when the pulse is off (at resonance) you will see a second positive pulse (double frequency). Look like a full wave rectified pulse even if you are only applying 1 pulse. much like in his pictures where you see a full wave rectiied signal going to the primary.
I'm working on a bigger coil witch i'm going to finish today, i have made the bobbins out of a pice of nylon and now i'm going to use the winding machine to make the bobbins. I'm going to use 28awg wire, The bobbins are gigantic there is a big window. My intention is to pulse it with low voltage high amperage lets say 12v 20A so i can have a high transformation factor, Cause the voltage seeing in the switch during the off pulse will be = to the resonant voltage divided by the transformation factor, so the switch must handle kv. I'm burning tens of mosfets here. When the resonance is achieved and we put power into it the thing the mosfet works better. I have only 600v warp speed igbts high amperage so i think is the only one that will fit the job. I also have a high voltage hexfet 1000v but is rated only 6 amps--- high rds on
I'm pretty much sure the pll purpose is also to achieve soft switching (quasi-resonance). Could be achieved with pwm but i don't know how to do it. I think that dan danford design was based in this.
I have designed my pll to run at 5v level and the driver at -5+0+12 volt level so the 0 goes to the source this way the gate will reverse the voltage improving the switch speed. This improved a lot the circuit performance. However i'm burning many components like drivers and the voltage regulators, seems like the high voltage pulse is going thru the voltage regulators.