Patent ID: 6917527

Claim:
A switching power supply having a first main switch having its one end connected with a negative electrode of an input voltage, a second main switch having its one end connected with a positive electrode of the input voltage, a first magnetic element having its one end connected with the other end of the first main switch and inducing a voltage to be an output by turning on/off of the first main switch and the second main switch, and a second magnetic element having its one end connected with the other end of the second main switch and having its other end connected with the other end of the first magnetic element, the second magnetic element inducing a voltage to be an output by turning on/off of the first main switch and the second main switch, the switching power supply comprising: a first diode having its anode connected to the first magnetic element via a first capacitor and having its cathode connected to a connection point between the first magnetic element and the second magnetic element; a second diode having its anode connected to the cathode of the first diode and having its cathode connected to the second magnetic element via a second capacitor; and an auxiliary switch arranged between the cathode of the second diode and the anode of the first diode and turned on when both the first main switch and the second main switch are off.