| 摘要 |
PURPOSE: To make it possible to discriminate a cause of overcurrent easily, by detecting an overcurrent caused by a fault in an inverter circuit and an overcurrent caused by an overload of a compressor separately, and displaying the abnormal state. CONSTITUTION: An overcurrent caused by short circuit of a switching element in an inverter circuit 4 is detected by a short-circuit circuit 9 with a short detection time and inputted to an interrupt port. An overcurrent caused by an overload of a compressor 5 is detected by an overcurrent integration circuit 10 with a longer detection time and inputted tp another interrupt port or a general port in a microcomputer 7. When the short-circuit signal is detected by the microcomputer 7, the compressor 5 is stopped. When the a plurality of abnormal signals are inputted to the interrupt port and detected many times, the microcomputer 7 generates an abnormal signal to forbid the restart of the compressor 5. When abnormal signals from the overcurrent integration circuit 10 are detected at the interrupt port or the general port, an abnormal state continues in the display and the compressor 5 is stopped until the overcurrent signal is finished in detection. |
