| 摘要 |
When an abnormality occurs in a refrigeration cycle, the inverter motor provided in the air conditioner is stopped reliably and contacts of the main relay are prevented from degradation and fusion. A power circuit 1 of the air conditioner includes a rectifier circuit RC, a capacitor C (smoothing unit), a main relay 10 provided on a current path between the rectifier circuit RC and the capacitor C, an inverter circuit 30, a microcomputer 100, and a delay circuit 40. The microcomputer 100 has an inverter circuit control unit 110, a main relay opening/closing control unit 120, a waveform forced cut-off unit 130, and a cut-off signal output unit 140. Where a high-pressure switch 200 (abnormality detection unit) detects a high-pressure abnormality and outputs a high-pressure abnormality signal to the waveform forced cut-off unit 130 when the main relay 10 is in a closed state, the waveform forced cut-off unit 130 electrically cuts off the inverter circuit control unit 110, and the cut-off signal output unit 140 outputs a cut-off signal, which sets the main relay 10 to the open state, to the main relay 10 via the delay circuit 40. |
