| 摘要 |
PURPOSE:To increase reliability of a compressor protecting device by comparing the speed of rotation of a compressor with the speed of rotation for comparison, judging existence of abnormality, and releasing a clutch when there is an abnormal condition. CONSTITUTION:When an engine is connected to a compressor by operating an electromagnetic clutch, a pulse for the speed of rotation of a rotor and a pulse for the speed of rotation of a disk are detected by their respective pickups, and inputted into a processing circuit 19. This processing circuit 19 judges whether the clutch is in a normal or an abnormal condition based on difference in pulses in the speed of rotation and the on or off condition of the clutch. When judged abnormal, another comparison is carried out after a certain period of holding time and, when there is still a difference, the clutch is disconnected. This construction increases reliability. |
