BASIC FEATURES

SENSORS

Sensors are mostly electronic devices used to monitor or capture something.

For example, an optical sensor to count the number of items on the treadmill.

A complete system that has a sensor and produces an electric

output signal is called a transducer.

FEATURES

SUPPLY

The sensors are designed for industrial DC voltages (usually in the automation they use

24 volts), ac or universal (both)

OUTPUTS

If the electric output signal can be any value between certain limits, the sensor is analog. Typically, the controller receives the signal is digital and, therefore, uses an AD converter.

If it can be only two values, for example, 120mv and 5v, the sensor will be digital.

APPLICATIONS

Widely used in medicine, automation, robotics.

Medical Pulse Sensor

TYPES OF SENSORS

Depending on your application there are various families and types of sensors for use

POSITION

Compared with a reference, determine the physical location

Potentiometer (resistance)Ultrasonic (measures time by

acoustic waves)Encoders (angular motion)

Inductive (capture ferromagnetic materials by varying

the electromagnetic field)Capacitive (electrostatic field variation).

OPTICAL

The transmitter sends the light that is captured by the receiver

TEMPERATURE

The most common and cheapest is the thermocouple. But it is not accurate for temperatures below 1 ºC

MAGNETIC

Detect magnets through the varying magnetic field