The QRC method is a quasi-resonant switching power supply circuit based on RCC, which constitutes a simple isolated power supply using 1 main switch and 1 rectifier diode.
It is widely used mainly for consumer household appliances with relatively low electric power, characterized by low partscost and low cost.

High efficiency: While the DCR snubber is always lost, the power clamper operates only when necessary, thus improving efficiency especially at light loads.
High reliability: There is no deterioration over time against repeated surge.

In a transformer design where 0 <α <(VQ (MAX) - VNP - Vin), VCL that satisfies VNP The closer the VCL value is to the VNP voltage, the larger the power clamper loss. Conversely, the closer it is to the (VQ (MAX) × β - Vin) voltage, the smaller the loss.