| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a photocoupler insulated analog transmission circuit that can easily correct the influence of transmission characteristic dispersion and secular change of a photocoupler while adopting analog transmission, and provide a voltage detecting circuit using this analog transmission circuit. SOLUTION: An insulated analog transmission circuit 10 having a photocoupler FCO formed of an input a-b side light emitting element LEO and an output e-f side light receiving element PQO, and an operating power source Vcc of the light receiving element PQO. In this case, a reference voltage generating circuit selectively connected to the operating power supply Vcc to make it a power source is connected to the light emitting element LEO, and the reference voltage generating circuit is connected to the operating power source Vcc to put the photocoupler FCO in action so as to output voltage at the time of input of the reference voltage.</p> |
