RUSH-CURRENT PREVENTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent breakdown of an MOSFET to short-circuit a resistor part for rush-current prevention.SOLUTION: A rush-current prevention circuit 50 includes: a resistor part 51 provided between a DC voltage source (for example, a DC link voltage Vo) and a smoothing capacitor 34, and preventing a rush current flowing into the capacitor 34 at the time of applying the DC link voltage Vo; and an MOSFET 52 connected in parallel to the resistor part 51 and short-circuiting the resistor part 51 after completion of the prevention operation to the rush current. The resistor part 51 has first resistors 51-1a to 51-1d and a second resistor 51-2 that are serially connected. The rush-current prevention circuit 50 further includes a first capacitor 54 connected in parallel to the resistor part 51, and a second capacitor 55 connected in parallel to the first resistors 51-1a to 51-1d and constituting an RC snubber circuit with the second resistor 51-2.