Posted on Jun 11, 2012

Hall-effect switches have several advantages over mechanical and optically coupled switches, They`re insensitive to environmental light and dirt, they don`t bind, and they don`t sustain mechanical wear. Their major drawback is that they require three wires per device. The circuit shown, however, reduces this wire count toN + 1 wires for N devices.

Click here to download the full size of the above Circuit.

Amplifier IClA is configured as a current-to-voltage converter. It senses the sensor assembly"s output current. When the Hall-effect switch is actuated, the sensor"s output current increases to twice its quiescent value. Amplifier IC1B, configured as a comparator, detects this increase. The comparator"s output decreases when the Hall-effect switch turns on. The circuit also contains a fault-detection function. If any sensor output wire is open, its corresponding LED will tum on. If the power-supply line opens, several LEDs will tum on. A short circuit will also tum an LED on. Every time an LED turns on, Ql turns on and the alarm relay is actuated.

Leave Comment

characters left:

New Circuits



Popular Circuits

Motorcycle 13.6V 3A charger
Solar Power walkway marker Led display
PIC16F84A based LC Meter circuit with explanation
LED Flashlight Use Super capacitor Schematic Diagram
Bots Circuit Designs
water sensor circuit using 555 timer
Microphone Mute circuit
petrol gas switch for pajero
Audio clipping indicator circuit
CVS Oral Thermometer Dissection
Common intermediate frequency amplifier circuit having a circuit and on the radio