DRIVE CIRCUIT OF NON-CONTACT RELAY

摘要

PROBLEM TO BE SOLVED: To reduce a current to be supplied when a plurality of input voltages are supplied to a photodiode as a predetermined current by a constant current circuit. SOLUTION: The drive circuit of a non-contact relay includes one photodiode PC1 in which an input and an output are insulated, and which is provided between a positive potential side line and a negative potential side line. This photodiode PC1 is driven by the plurality of the input voltages. The input voltage applied to the positive potential side line is converted to a constant current by the constant current circuit 10 and supplied to the photodiode PC1. In this case, a part of the current supplied from the positive potential side line to the constant current circuit 10 is supplied to the negative potential side line as bypass current by a bypass current circuit 30. The bypass current circuit 30 is operated by a bypass current control circuit 20 when the voltage is applied to the positive potential side line. COPYRIGHT: (C)2005,JPO&NCIPI