| 摘要 |
PROBLEM TO BE SOLVED: To provide an inverter which is low-cost and simple-structured and can detect the grounding of an output line to a load. SOLUTION: An inverter includes a current detection circuit for detecting an earth current which is connected to the positive side and the negative side of a DC bus. The current detection circuit has a two-way photo coupler 3 installed on the positive side of the DC bus, a resistor R4 installed on the negative side of the DC bus, and a comparator circuit 4. On the positive side of a closed circuit including a rectifier circuit 1 and a DC intermediate capacitor C1, a resistor R3 for limiting the earth current is inserted. |
