Patent ID: 6956751

Claim:
A motor power supply comprising: a rectifier which rectifies external AC power into DC power; a capacitance which smoothes the DC power; an inverter having first and second connection terminals and which converts the DC power into driving power to be supplied to a motor; a first resistance having a first end connected to a positive power output terminal of the rectifier and a second end; an over voltage protection diode having a cathode connected to the positive power output terminal of the rectifier and an anode connected to the second end of the first resistance; an over voltage protection switching element connected between the anode of the over voltage protection diode and a second end of the capacitance; a second resistance having a first end connected with the second end of the capacitance and a second end; a first switching part which selectively connects the first end of the capacitance with one of the positive power output terminal of the rectifier and the second end of the first resistance; a second switching part which selectively connects the first connection terminal of the inverter with one of the first end of the capacitance and the second end of the second resistance; and a controller which controls the first and second switching parts to selectively connect the first and second resistances, respectively.