| 摘要 |
PURPOSE:To prevent a thyristor drive circuit from operating by an input signal by adding a zero cross detector. CONSTITUTION:When a zero cross timing signal (c) is inputted via a zero cross detector 7 to the inpt port 2 of a microcomputer 1, an input/output port 3 outputs as an output mode a control signal (e) to a thyristor drive circuit 9. The port 3 is operated to receive an input from a detector 8 as an input mode between the timing signal (c) and the next timing signal. In this manner, a drawback that the thyristor drive circuit 9 is operated by the input signal can be eliminated. |
