| 摘要 |
PURPOSE:To prevent a secondary failure by comparing the ratio of an engine rpm. to a revolution number of an air conditioner refrigerant compressor with the specified value, in order to determine engagement and disengagement of a solenoid clutch and actuating a disengagement holding circuit in case the disengagement is selected. CONSTITUTION:Pulse signals of an engine rpm. detector 1 and a refrigerant compressor's revolution number detector 2 are sent to a comparator 7, via related waveform shaping circuits 3 and 4 and F-V converters 5, and 6. The comparator 7 decides whether ratio of DC voltages to both the revolution numbers may be equal to the specified value or not and once finding the revolution number of the compressor abnormal, the comparator 7 issues a high level output to a holding circuit 8. The holding circuit 8 sends a solenoid clutch deenergizing signal to a solenoid clutch 9 to disengage it so as to stop the compressor and it is maintained under the inoperative condition. A secondary failure may be thus prevented. |
