Proximity capacitive sensors - DC Characteristics

The capacitive proximity sensors and switches are used as electronic equipment for automation of production processes. Brief information is given underneath about their functions, characteristics, installation rules and electrical circuits of connection.

Operating principle and purpose

The presented capacitive sensors are used to commutate direct current electrical circuits. Their action is based on a capacitive principle. When changing the dialectical permeability in front to their active part, their output switches over - the electric circuit opens up or shuts up. They react to metal or non-metal objects. The sensors have a potentiometer to adjust their sensitivity. When there is object in front of their active part, the output indicator is on. They are used as level controllers of bulk materials. They are widely used to automate production processes in the food processing industry, paper industry, textile industry etc.

Rules for installation of unshielded capacitive sensors

a) Installation a sensor to a metal plate

Installation of a capacitive sensor in a metal plate

b) Installation of two or more sensors

Installation of two capacitive sensors

Sn - номинално разстояние на включване

D - диаметър на датчика

Connection circuits of sensors

Scheme of connection of PNP capacitive sensor

Scheme 10 (PNP/NO+NC)

Scheme of connection of NPN capacitive sensor

Scheme 20 (NPN/NO+NC)

Output characteristic (residual voltage)

Features of connecting a capacitive load to sensors with impulse protection against current overload

Wiring diagram of capacitive sensor type PNP/NO with short-circuit protection

Connection of capacitive load to PNP type sensor

Wiring diagram of capacitive sensor type NPN/NO with short-circuit protection

Connection of capacitive load to NPN type sensor