Circuit diagram

Here is the circuit diagram of a magnetic proximity switch that finds a lot of applications in abounding fields.The ambit is based on a alluring reed switch(S1) as the adjacency sensor. A monostable multivibrator based on NE555 (IC1) and a toggle cast bomb based on CD4013 (IC2) does the blow of the circuit.

When a allurement is accomplished in adjacency of S1 it closes to accord a abrogating activate at pin 2 of IC1.The achievement of IC1 goes top for a time determines by R2 and C2.This clocks the IC2 active as a toggle cast flop.The achievement (pin 1 ) of IC2 goes top and the transistor Q1 is biased to ON.The broadcast is activated and so do the accessories affiliated to the relay.The LED D1 glows if IC1 is triggered.

A very simple proximity detector electronic project can be designed using this schematic circuit . This proximity detector electronic project use a tone decoder integrated circuit ( NE567 ) that will provides a signal with a frequency about 100Khz . This signal is fed to one sensor . The sensor can be constructed from two cooper or aluminum plates or wires or other conductive material .

Simple Proximity Detector Schematic Circuit Diagram

When an object is placed near the sensor , the capacitance between sensor is increased . The Q1 and Q2 transistors will amplify the signal and fed it to the NE567 IC , that will make the LED1 to glow . C8 and R4 phase shift the VCO signal from the NE567 so that the U1 can detect its own output signal .

This electronic project circuit require a 9 volts DC power supply circuit .