| 摘要 |
PROBLEM TO BE SOLVED: To enable the following in a device configured such that when it is detected that a load device is being powered on at power recovery from power interruption or at load device connection as a load, a main circuit contact is opened to prevent power supply to the load: even though the load device is a device in which an electronic control function such as thyristor control is provided, a noise preventing capacitor is installed between electric wires between a power switch and a power source, and a current is passed through the noise preventing capacitor even if the power switch of the load device is off, power is supplied when the power switch is off, and then the load device can be used by turning on the power switch.SOLUTION: A means for detecting an on/off state of a load device detects a current passing through an impedance connected in parallel with a contact that opens and closes the main circuit and determines that the load device is on when the magnitude of the detected current is larger than a threshold. |
