| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor drive circuit the configuration of which is easily simplified, though the circuit is to detect insulation resistance for every portion.SOLUTION: This motor drive circuit includes a power supply line connected to a DC power supply, an inverter the input side of which is connected to the power supply line and which converts input power to AC power and outputs it to a motor, a power supply conduction switch provided on the power supply line to switch conduction and cutoff of the power supply line, a voltage detecting part for detecting a voltage between the DC power supply and the power supply conduction switch, and an insulation resistance detecting part which performs operation to detect the insulation resistance of the anterior portions of the power supply conduction switch on the basis of the detection result of the voltage detecting part with the power supply conduction switch cut off, and thereafter performs operation to detect the insulation resistance of the posterior portions of the power supply conduction switch on the basis of the detection result of the voltage detecting part with the power supply conduction switch turned on. |
