| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an insulation detector capable of increasing the breakdown voltage without using a high breakdown voltage semiconductor relay.SOLUTION: An insulation state detection device is connected to a positive terminal and negative terminal of a DC power supply (B) insulated from a grounding potential part and detects the insulation state of the DC power supply on the basis of a charging voltage at the time of charging a flying capacitor (C1) with a charge amount according to a power supply voltage of the DC power supply and a charging voltage of the flying capacitor detected by voltage detection means (15). A selector switch for switching between charging and discharging of the flying capacitor comprises: two or more semiconductor relays (Sa and Sb) that are connected in series; and two or more balance resistors (Ra and Rb) that are connected in parallel to the semiconductor relays. The selector switch is provided with switch control means (20) that controls the opening and closing of the selector switch so as to charge the flying capacitor and detect a voltage of the flying capacitor.</p> |
