Compressor drive controller.

摘要

A compressor drive controller for use in an automobile air conditioner wherein the rotational speed of the engine (24) is detected basing on the signal from, for example, the ignition coil (28) and the rotational speed of the compressor (26) is detected by means of an electromagnetic pickup (22) provided at the output rotor (20) of the electromagnetic clutch (3) so that the electromagnetic clutch is deenergized when the ratio of both rotational speeds reaches a predetermined value, thereby detecting reliably the occurrence of locking of the compressor.