Sensors

In technologies like robotics and automation, some devices are controlled manually by someone in a different environment/location. But most of the time when automation is involved, sensors are used. Most of automated devices like robots use sensors in order for it to gather data in its surroundings/environment before it executes an action depending on what it is programmed to do. Listed are 5 of the commonly used sensors by hobbyists.

Infrared Detector

Light Dependent Resistor

1. Light Sensors
This are sensors that convert light signals to electric signals.
An example of this is the LDR (light dependent resistor) which changes its resistance when struck by light. Another example is the Infrared Light Detectors, where the junction of the device exhibit a close switch when struck by infrared radiation. Infrared detectors are usually used in line followers.

Open Type
Ultrasonic Sensor

Closed Type
Ultrasonic Sensor

2. Ultrasonic Sensors
This are components that are used to create and detect ultrasonic sound waves. This sensors are usually used as proximity sensors like collision avoidance system of high end cars.

Hall Element

3. Magnetic Sensors
This are sensors used to detect magnetic field and sometimes also detect magnetic polarity.
A good example of this are hall elements, which are usually used in brushless cooling fans that controls the direction of current of the coils when changes in magnetic polarity is detected.

Pyro Sensor

4. Temperature Sensors
This are sensors by the name itself are used to detect thermal signatures of the surroundings.
An examples of this is the thermocouple, which uses two metals producing voltages depending on its temperature differences. Another sample is the pyro sensor that detects heat depending of the design of the circuit with it.

NXT Lego Mindstorm
Gyro Sensor

5. Gyro and Force Sensors
In robotics, this sensors are usually used to control balance and grip.
An example of this type of sensors are gyro sensors used in lego mindstorms nxt.





Due to the advances in technology, a combination of sensors are implemented to give  more precise action/movements. Also, due to the development of computers and softwares, technologies such as cameras nowadays can be used as sensors. There are also high end sensors that detects signals from the brain in order to control prosthetic arms/legs.