| 摘要 |
PURPOSE:To prevent the generation of EMI and to ensure high resolving power when the speed of a moving body is low, by outputting an original signal or divided signal having frequency, which corresponds to the moving speed of the moving body, corresponding to the change in the speed of the moving body. CONSTITUTION:A-phase and B-phase pulses corresponding to the rotational speed of a motor and a Z-phase pulse showing that the rotary shaft of the motor reaches a predetermined position are respectively outputted from a sensor part 1. Said pulses are applied not only to a synchronous circuit 3 through a waveform shaping circuit 2 but also to a multiplier circuit 4. When the motor rotates at a low speed, a change-over frequency setting circuit 6 outputs no signal Sd and the synchronous circuit 3 outputs a multiplied pulse and, as a result, a speed can be detected with high resolving power. When the motor rotates at a high speed and the number of rotations exceed the speed set to each of manual switches S1-S4, A- and B-phase pulses are outputted.
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