POWER SUPPLY SYSTEM WITH SELF-EXCITED DRIVE FUNCTION

A power supply system with self-excited drive function includes a power supply apparatus (100), a logic disconnection circuit (10), a self-boosting circuit (20), a protection circuit (30), and a current sensing unit (40). The logic disconnection circuit (10) is coupled between a positive power wire (Lp+) and a negative power wire (Lp-). The self-boosting circuit (20) converts a voltage into an auxiliary voltage (Va), and the self-boosting circuit (20) is coupled to the logic disconnection circuit (10) to receive the auxiliary voltage (Va). The current sensing unit (40) outputs a current sensing signal (Is) according to a current flowing through the positive power wire (Lp+) or the negative power wire (Lp-). The protection circuit (30) makes a short circuit or an open circuit between the positive power wire (Lp+) and the negative power wire (Lp-) according to the current sensing signal (Is). The logic disconnection circuit (10) disables or enables the self-boosting circuit (20) according to the voltage between the positive power wire (Lp+) and the negative power wire (Lp-).