Inductive Proximity switch produces high frequency alternating field at the sensing face. When any metallic material enters in the sensing zone of the switch, the field gets disturbed. A Sensitive detector circuit senses this change which is further processed by amplifier circuit to produce output signal.

When the object enters in the sensing zone of the switch, capacitance between two plates of capacitor (one plate is represented by electrode at sensing .face of the switch and another by all surrounding material which is connected to the earth) changes. As soon as capacitance value crosses preset level, oscillator starts. This change is detected and resulted in an output signal.

Salient Features

Non contact operation
Potential free contacts suitable for 24 VDC / 240 VAC.
High operating distance up to 25 mm.
Totally enclosed - Robust - cast Al / Plastic enclosure for switch as well as magnet. IP 67.
A Special stay-put type of switch is developed which can be used to sense direction.
Operating Temp up to 0-120 'C

Beam of invisible pulsed modulated infra-red light is produced by emitter. This beam is sensed by receiver at another end (in through beam version) or reflected by object and received by received placed near emitter (in diffuse version). When this beam is interrupted by object, the receiver signal gets changed and signal is produced.

Ultrasonic sensors measure the distance or presence of target objects by sending a pulsed ultrasound wave at the object and then measuring the time for the sound echo to return. Knowing the speed of sound, the sensor can determine the distance of the object.