| 摘要 |
PURPOSE:To prevent the erroneous operation of a control rectifier and to improve the reliability by limiting the number of inversions of the compared output of a carrier with a modulation wave in the increasing and decreasing zones of the carrier once at every increasing and decreasing zones. CONSTITUTION:A latch circuit 28 has functions of inputting an output 3 of a comparator 22 to a terminal D or outputting a signal of an input D to an output Q by a signal of enable input E and latching. On the other hand, an exclusive logic circuit 29 compares a resultant gate signal 3 as the output signal of the output Q of the latch circuit 28 with a zone discrimination signal 27, and generates a signal for latching the output Q of the latch circuit 28 when the signal 3 coincides with the signal 27. The signal 27 is a signal representing the increasing and decreasing zones of a carrier. In this manner, the erroneous operation of a control rectifier can be prevented, thereby improving the reliability. |
