Inverter

摘要

When a power source connected to an electrolytic capacitor (5) is interrupted, a switching control circuit (6a) of an inverter activate the switching element of an inverter main circuit (7a) to supply a load with a current, so that the electrolytic capacitor (5) is discharged. An electrolytic capacitor capacitance calculator (10a) calculates the capacitance of the electrolytic capacitor on the basis of a discharge quantity determined from the outflow current (Ic) of the electrolytic capacitor (5) and a discharge time and a discharge voltage W V as a voltage drop from the discharge start of the electrolytic capacitor (5).