For example, the peak at 20 MHz in the spectrum is caused by the parasitic oscillation due to the output capacitance of the MOSFET and the leakage inductance of the transformer.
The circuit, with over-current protection of output transformer original side average current and side peak current, adopts pulse transformer coupling MOSFET driving circuit.
From two aspects of theory and practice, this article more systematically expounded the peak sample transformer rotating shaft cotangent coding scheme and its engineering design principles.