| 摘要 |
PURPOSE:To generate a normal zero cross pulse by outputting an inverter output and a variation detecting circuit output selectively as the zero cross pulse. CONSTITUTION:A full-wave or half-wave rectified voltage VIA or VIB from an AC power source is inputted to an inverter 1, whose output V1 is supplied to a changeover switch 3a. A variation detecting circuit 2 generates an output pulse signal V2 synchronizing with level variation points (from H to L and from L to H) of the output V1 of the inverter 1, and output contacts NO and NC of a switching circuit 3 associated with a changeover switch 3 select the output V1 or output V2 to be outputted as a zero cross pulse, thus generating the normal zero cross pulse. |
