| 摘要 |
PURPOSE:To prevent erroneous operation due to noise, by detecting rotary speed based on timing except those where variation sequence of timing signal produced synchronously with the rotation of motor does not match with the variation sequence stored in a memory circuit. CONSTITUTION:A timing signal generating circuit 8 outputs timing signals A-C based on pulse signals fed from sensors 6a-6c. A memory circuit 9 outputs timing signals A'-C' every time when the pulse signal varies. A comparison circuit 10 outputs an unmatch signal when the timing signals A-C do not match with timing signals A'-C'. An error detecting circuit 11 measures interval of the timing signal A and detects a rotation error with respect to a target rotation. Upon output of a noncoincidence signal, interval of timing signal except those where a noncoincidence signal is outputted is measured. |
