•  
  •  

Magnetic proximity sensors

Here is an interesting circuit for a magnetic proximity switch which can be used in various applications.
The magnetic proximity switch circuit, in principle, consists of a reed switch at its heart. When a magnet is brought in the vicinity of the sensor (reed switch), it operates and controls the rest of the switching circuit. In place of the reed switch, one may, as well, use a general-purpose electromagnetic reed relay (by making use of the reed switch contacts) as the sensor, if required. These tiny reed relays are easily available as they are widely used in telecom products. The reed switch or relay to be used with this circuit should be the ?normally open? type.
When a magnet is brought/placed in the vicinity of the sensor element for a moment, the contacts of the reed switch close to trigger timer IC1 wired in monostable mode. As a consequence its output at pin 3 goes high for a short duration and supplies clock to the clock input (pin 3) of IC2 (CD4013?dual
D-type flip-flop). LED D2 is used as a response indicator.
This CMOS IC2 consists of two independent flip-flops though here only one is used. Note that the flip-flop is wired in toggle mode with data input (pin 5) connected to the Q (pin 2) output. On receipt of clock pulse, the Q output changes from low to high state and due to this the relay driver transistor T1 gets forward-biased. As a result the relay RL1 is energised.

If there are any problems please contact webmaster@electronic-circuits-diagrams.com

Please share & like

White Rodgers 70-120224 Solenoid SPNO 36 VDC Isolated Coil Continuous Duty
$46.99 White Rodgers 70-120224 Solenoid SPNO 36 VDC Isolated Coil Continuous Duty picture
Automatic Valve L0502AAWR-AA Valve L0502AAWRAA
$62.33 Automatic Valve L0502AAWR-AA Valve L0502AAWRAA picture
SMC SY7120-3DZ-02 0.15-0.7 MPA 5 PORT 2 POSITION SOLENOID VALVE LOT OF 16
$24.99 SMC SY7120-3DZ-02 0.15-0.7 MPA 5 PORT  2 POSITION SOLENOID VALVE LOT OF 16 picture
NUMATICS 122BB4Z2MN000F 150 PSIG SOLENOID VALVE LOT OF 4
$9.99 NUMATICS 122BB4Z2MN000F 150 PSIG SOLENOID VALVE LOT OF 4 picture
1x DC24V 1/4"Electric Solenoid Valve N/C Feed For RO Water Air Quick Connect ^@M
$5.56 1x DC24V 1/4