| 摘要 |
PURPOSE:To obtain a simple polarity inverting electronic switch, by connecting the input section of a photocoupler in series between one of the power supply terminals which are normally opened or normally closed and the output circuit, and connecting the output section of the photocoupler to a polarity switching circuit. CONSTITUTION:A detecting circuit 1 consists of, e.g. a proximity detecting circuit and a photoelectric detecting circuit for an object to be detected, and a switching circuit 2 switches the polarity of the output signal of the detecting circuit 1. An output circuit 4 switches the switching element in accordance with the detecting signal. A terminal A out of terminals connected to a power supply 10 is normally opened and a B is normally closed, and an input (light emitting diode) 3P of a photocoupler is connected to the terminal A and an output (photodetector)3S of the photocoupler is connected to the switching circuit 2. The polarity switching of the output signal is made only when the power supply 10 is connected to the power supply terminal A, and the switching circuit 2 is inoperative when the power supply 10 is connected to the terminal B. Thus, the switching of the operating mode can be made simply through the selective use of the power supply terminals. |
