| 摘要 |
PURPOSE:To prevent the secondary trouble due to a compressor trouble from occurring by a method wherein the connection and disconnection of an electromagnetic clutch are performed based upon the result of comparison between the DC voltage taken from the rotation of an engine and its set value and upon the result of comparison between the ratio of said DC voltage taken from the rotation of the engine and the DC voltage taken from the rotation of a refrigerant compressor to its set value. CONSTITUTION:Pulse signal corrsponding to the rotation of the engine are obtained with a pulse generator 1 and converted through a wave-form shaping circuit 3 and a frequency-voltage converter circuit 5 to DC voltages and, after that, compared at an comparator 7 with the set value and the resultant discrimination signal is inputted to a drive decision circuit 9. On the other hand, pulse signals obtained with a pulse generator 2 are similarly converted to DC voltages and, after that, compared at an comparator 8 with the voltages of the converter 5 so as to discriminate whether said two voltages are in the relationship of the predetermined ratio or not and the resultant discrimination signal is inputted to the drive decision circuit 9. The electromagnetic clutch 2A is controlled by connecting and disconecting based upon the two resultant discrimination signals. Because the compressor trouble is easily detected and the connection and disconnection of the electromagnetic clutch is controlled in accordance with the detected result in such a manner as mentioned above, the secondary trouble can be prevented. |
