Mechatronics - ME2401 Proximity Sensor

? Proximity நெருங்கிய தன்மை = nearness

So What’s a Proximity Sensor? A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact.

Principle of operation A high frequency oscillator creates a field in the close surroundings of the sensing surface. The presence of a metallic object (inductive) or any material (capacitive) in the operating area causes a change of the oscillation amplitude. The rise or fall of such oscillation is identified by a threshold circuit that changes the output state of the sensor.

Inside the sensor

TYPES

Inductive Proximity Sensors 

 This type of sensor generates output signal or electrical signal when metal objects are either inside or entering into its sensing area from any direction. Eddy currents are induced on the metal targets which opposes the electromagnetic field.

Capacitive Proximity sensor

The plate inside the sensor acts as one plate of the capacitor and the target acts as another plate and the air acts as the dielectric between the plates. As the object comes close to the plate of the capacitor the capacitance increases and as the object moves away the capacitance decreases.

Applications

Industry Automation

Rear Parking sensors REAR PARKING SENSORS They help you by indicating objects coming closer to the rear bumper of your vehicle while reversing, thus aiding you to park your vehicle in tight spots.

Proximity sensor Gyro sensor Ambient light sensor Proximity sensor Gyro sensor

 Engine Control Units use the information transmitted by the sensor to control parameters such as ignition timing and fuel injection timing.

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