| 摘要 |
PURPOSE:To reduce the withstand current amount of a driving switching element by slightly shortening the length of a pulse applied to a stator winding of the semiconductor motor at the end, thereby providing a timing interval for switching the current to the next phase winding and thereby preventing the peak current produced at the winding. CONSTITUTION:A record counter 11 starts counting upon receipt of a voltage E1, a ring counter 12 is operated by the output pulse of the terminal (1), the output pulse of the ring counter 12 is switched to the next phase at every counting cycle, for example, from the output (a) to the output (b). If a pulse is produced at the terminal (8) or (9), it is applied through an OR gate 19 to AND gates 28, 35, and the output of the gate 35 becomes 1. A transistor 37 is conducted with the 1 output, and no voltage E2 is applied to the comparator circuit 40. Accordingly, both the outputs of the circuit 40 and the gate 20 become 0. Thus, the transistor 5 is turned OFF, and the current i1 to the winding 1 is intercepted. |
