| 摘要 |
<p>PURPOSE:To make sensors such as pick-up unnecessary, by a method wherein rotational speed of a compressor is detected from frequency of AC voltage appearing at an armature coil of a generator driven by a compressor pulley. CONSTITUTION:Power rotation of an engine pulley 1 is transmitted by a belt 2 to a compressor pulley 3, and further transmitted from the compressor pulley 3 by a belt 4 to an alternator pulley 5. If difference between an engine rotational speed signal Ve and a compressor rotational speed signal Vc taken from AC voltage signal obtained from both ends of armature coils 21a-21c of the alternator becomes over a prescribed value, a protective device 8 excites a relay coil 15 and opens an electromagnetic clutch 16 so as to maintain the generating capacity of the alternator.</p> |
