| 摘要 |
PURPOSE:To enable a control to be attained with low noise and high promptness by short-circuiting both ends of a coil in a motor, when it is decelerated, by low resistance to apply a brake, counting then generated induced voltage of the coil and detecting the position of a rotor. CONSTITUTION:When a step motor is in a transfer from an equal speed drive to a deceleration drive, an MPU1 outputs a stop signal to a drive pulse generating circuit 2. Then transistors 11a, 11b in a ground side of drive circuits 3a, 3b turn on, and both ends of each of coils 8, 9 are connected through low resistance by diodes 12a, 12b and these transistors. On the other hand, when the MPU1 outputs the stop signal, an up-down counter 6 counts up and down signals generated by waveform shaping circuits 4a, 4b and an up-down pulse generating circuit 5. A count value of the up-down counter shows the number of steps in which a rotor advance after the MPU1 outputs the stop signal. |
