| 摘要 |
PURPOSE:To reduce external component parts and allow the informations of rotational directions to be kept, by generating constant time range pulse on the rise and fall of the rectangular wave signal of three-phase output, and by integrating the pulse to detect the speed. CONSTITUTION:Three-phase output signals A, B, C from a motor are waveform- shaped by a waveform shaping circuit 1. By a rectangular-wave-synthetic circuit 2, the operation of logical product is performed on two-phase arbitrary signal, and the operation of logical sum is added to produce the rectangular wave of triple frequency. After that, by a both edge detecting circuit 3, both edges are detected and trigger signal is produced. By the trigger signal, a monostable multivibrator 4 is worked, and constant time range pulse is generated. In the meantime, by a direction detecting circuit 5, either gate of a gate circuit 6 is opened. By this output, a positive and negative constant voltage generating circuit 7 is controlled, and the output of the circuit 7 is integrated by an integrating circuit 8 and is set to be a speed signal. |
