Circuit circuit principle of circuit protector outside the refrigerator

LC03-3.3 SOP8 TVS Static Protection 3.3V

Industrial Router Crystal 3.2*2.5mm 3225 26M (26.000MHZ) 12PF 10PPM 20PPM 30PPM

The protector consists of circuits such as buck rectification, delayed start, over-voltage, under-voltage sampling, and trigger control. The protector has functions such as overvoltage (>245V), undervoltage (<175V) protection, power-off delay (about 7 minutes), power consumption (<2w), and low cost.
IC and R4, C3 and so on constitute a single voltage regulator delay circuit, the delay time is t = 1.1R4C3, the delay of the graphical parameters is about 7 minutes. When protecting, LED1 (red) is on and the refrigerator socket is powered off; in normal operation, LED2 (green) is on.