Here is the next video on some more test that i carried out on request by PW.
TK-if you read this-->when we do our P/in math to the coil,would we go by the instantaneous voltage across the coil when the AMP switches on?,as using the battery voltage would only include power being dissipated in the rest of the drive circuit. It makes sense to me that the voltage across the primary coil is the voltage that should be used when calculating power consumption by the transformer it self,as the full battery voltage is never across the coil.
https://www.youtube.com/watch?v=tiirD9mTPZk
Measuring just the transformer primary as "input" is OK with me at this point. But... I still need to ask, and comment, about the circuitry and measurement points.
First, the scope probe reference clips are still connected internally at the oscilloscope, aren't they? So Picowatt's suggestion is a good one. If you are measuring the two sides of the transformer by connecting one probe "across" the Primary and one probe "across" the secondary or load, then you are connecting the two sides through the "ground" clips of both probes. It would be better, then, to avoid spurious ringing and other complications, to connect the Primary and Secondary "bottoms" with a short wire directly and use this connection as the Common Ground point for both probes.
Second... your driver circuit is a "high side load" or "low side switch" configuration. This means that the mosfet Drain voltage will be HIGH (at or near battery voltage) when the mosfet is OFF and will be LOW (near the zero voltage level, lifted by the voltage drop of the mosfet). But the mosfet Drain shares a common node with the Common Ground point for the toroid's windings. This means that the phase relationship between Gate Signal and the two signals read by the scope probes may be affected.
So, I'd like to see, if you have time, three scopeshots like this: (referring to my marked-up version of your schematic below)
One shot where one scope probe is connected where the FG is connected: probe tip at the connection marked "FG Red" and reference at "FG Black", and the other scope probe connected at "TP 1", with reference also at "FG Black".
Another shot where one scope probe is connected where FG is connected as before, and the other probe connected with TIP at "Common Probe Ground" (aka mosfet Drain) and reference also at "FG Black"
(These two shots of course "de-isolate" the FG's Black lead back to the system common ground established by the scope probe reference connections.)
A third shot where the two scope probes are connected at TP 1 and TP 2, with both references at "Common Probe Ground" using PW's suggested connection rather than relying on the probe ground lead circuit to make that connection.
Please do all the shots at the same frequency setting, scope channel voltage settings etc.
I think with these three sets of shots we should be able to see clearly the relationship between the mosfet On and Off times and the responses of the transformer windings.
(I haven't watched the latest video yet, so please excuse me if you've already done some of these suggestions)