| 摘要 |
PURPOSE:To reduce the number of sensors by selecting as a position signal a rotation detection pulse or the output pulse of a pulse generator in response to the length of the period of the rotation detection pulse. CONSTITUTION:A sensor 7 detects a marker 6 mounted on a rotor to output a rotation detection pulse. A retriggerable monostable multivibrator 9 outputs a signal which is a high level from the pulse input point of the pulse to a time for passing a time constant and a low level from it until next pulse is input. A switch circuit 10 outputs the pulse when an input signal is the high level and the pulse from the generator 1 when the input signal is the low level as a position signal. A waveform converter 36 applies a motor drive pulse i-k in response to the position signal to drive transistors 22-24. |
