| 摘要 |
PURPOSE:To enable a circuit to operate independently of the polarity of an external equipment by constituting a circuit by providing two photocouplers connected in series, an invertor to drive the two photocouplers simultaneously, a resistor to restrict a common current and two diodes. CONSTITUTION:Monitored and controlled items a1-an are connected to the cathode side of the photocoupler 1132 through the invertor 112, and the anode of it is connected to the cathode of the photocoupler 1131. Then, the two photocouplers 1131, 1132 are made able to be driven by one invertor 112, and currents to flow in the respective photocouplers are restricted by a common resistor 111. Furthermore, they are protected against a reverse electromotive force from an external output side by corresponding diodes 1141, 1142 respectively. Thus, since it can be used even if the polarities of the power sources of the external equipment sides are different, or even if the polaritie are mixed, an application range is extended. |
