| 摘要 |
PURPOSE: To prevent an excessive current spike by inverting the polarity of applied voltage after making dynamic brake act, in the case of inverting a reversible DC motor. CONSTITUTION: An initial command signal is outputted, being delayed by a delay device 23. A code comparator 28 outputs a signal on H level when the codes of the initial command signal and the delay signal are the same, and a signal on L level when they are different. Moreover, the comparator 42 outputs a signal on H level when the absolute value of the sum of the initial command signal and the delay signal is over the reference value, and a signal on L level when it is under the reference value. A logical circuit 38 outputs an intermediate command signal and a dynamic brake signal to a drive circuit 19 by switching a switch 35. When the output of the logical circuit 38 gets on L level, the switch 35 is switched, and the initial command signal is supplied to the drive circuit 19. |
