MAGNETIC PROXIMITY SWITCH

1. Here is the circuit diagram of a magnetic proximity switch that finds a lot of applications in many fields.
2. The circuit is based on a magnetic reed switch(S1) as the proximity sensor.
3.  A monostable multivibrator based on NE555 (IC1) and a toggle flip flop based on CD4013 (IC2) does the rest of the circuit.
4.  When a magnet is reached in proximity of S1 it closes to give a negative trigger at pin 2 of IC1.The output of IC1 goes high for a time determines by R2 and C2.
5.  This clocks the IC2 wired as a toggle flip flop.The output (pin 1 ) of IC2 goes high and the transistor Q1 is biased to ON.
6.  This clocks the IC2 wired as a toggle flip flop.The output (pin 1 ) of IC2 goes high and the transistor Q1 is biased to ON.

NOTES:

• Switch S1 can be a general purpose magnetic reed switch.
• The equipment to control can be connected using NC,NO and C points of the relay according to the application.
• Use a 12 regulated power supply for powering the circuit.