JK7 proximity switch circuit

The proximity switch is a non-contact object detection switch that can be used for various purposes such as alarming. The proximity switch circuit of the JK series proximity switch application-specific integrated circuit , which imitates the Siemens
TCA205 and TCA305 circuits, is shown in Figure 13J165 and Figure 13-166.     When a metal object approaches the induction coil, the JK integrated circuit receives the induction signal , rectifies the oscillation signal , and transmits it to the driver through the Schmitt circuit. After an appropriate delay, the voltage signal is added to the base of the triode , and make it conductive, the trigger signal is output from pin 7 of JK , and is input to the control electrode of the bidirectional thyristor V through the bidirectional trigger diode VD, and makes it conductive, thus turning on the load power supply.