Method and device for discharging output capacitor of power supply

A power supply, comprising:

• a primary side configured to connect to a mains voltage and receive a voltage signal to be converted;
• a secondary side configured to output a converted voltage signal;
• and
• a transformer connected between the primary side and the secondary side and configured to convert the voltage signal, wherein the secondary side comprises:
• an output capacitor,
• synchronous rectification (SR) circuitry configured to rectify the converted voltage signal from the transformer,
• detection circuitry configured to detect that the SR circuitry is inactive after no switching activity is sensed for a predetermined time at drains of the SR circuitry,
• determining circuitry configured to determine that the primary side is disconnected from the mains voltage after the SR circuitry is detected to be inactive, and
• discharging circuitry configured to discharge the output capacitor based on the determination that the primary side is disconnected from the mains voltage.

A power supply, comprising:

• a primary side configured to connect to an input voltage and receive a voltage signal to be converted;
• and
• a secondary side configured to output a converted voltage signal, the secondary side comprising a controller configured to:
• detect that synchronous rectification (SR) circuitry at the secondary side is inactive after no switching activity is sensed for a predetermined time at drains of the SR circuitry,
• determine that the primary side is disconnected from the input voltage after the SR circuitry is detected to be inactive, and
• discharge an output capacitor at the secondary side based on the determination that the primary side is disconnected from the input voltage.