| 摘要 |
PURPOSE:To prevent an object from running away due to malfunction by allowing a sender side to superimpose a carrier on a control signal and allowing a receiver side to identify the carrier in sending and receiving a control signal for start or stop via light in a signal transmitter using an optical link. CONSTITUTION:A transmitter/receiver for a control signal to a driving circuit 2 of a power converter 1 consists of a carrier generating circuit 10, an AND circuit 11 ANDing an output signal from the circuit 10 and a start/step control signal, an electrooptic conversion circuit 3 converting the output electric signal from the AND circuit 11 into an optical signal, a transmission optical fiber 4, a photoelectric converter 5 converting the optical signal through the optical fiber into an electric signal, and a carrier identification circuit 12 comprising the combination of a frequency/voltage converter 13 and a voltage comparing circuit 14 identifying the superimposed output signal from the converter 5 nd supplying the output to the circuit 2 when the carrier is superimposed. Through the constitution above, even if the converter 5 malfunctions and generates a signal, the circuit 12 discriminates that the carrier is superimposed and no transmission to the circuit 2 is caused. |
