OPTICAL COUPLING TYPE SEMICONDUCTOR RELAY

摘要

PROBLEM TO BE SOLVED: To prevent malfunction when an excess optical signal is generated from a light emitting diode. SOLUTION: This relay is provided with a light emitting diode 1, a photo diode array 2 receiving the optical signal from the light emitting diode 1, an output MOSFET 3 whose gate and source receive the optical electromotive force of the photo diode array 2, a 1st MOSFET 4 of a normally-on type relay whose gate connects to a cathode of the photo diode array 2, a high resistive element 9 connected between a source of the output MOSFET 3 and a cathode of the photo diode array 2, and a resistive element 10 connected between a source of the 1st MOSFET 4 and a cathode of the photo diode array 2.