How does an infrared sensor work?

An infrared sensor detects infrared radiation emitted by objects and converts it into an electrical signal.

Infrared sensors work by detecting infrared radiation, which is a type of electromagnetic radiation with longer wavelengths than visible light. When an object emits infrared radiation, the sensor detects it and converts it into an electrical signal that can be processed by a microcontroller or other electronic device.

There are two main types of infrared sensors: passive and active. Passive infrared sensors detect the natural infrared radiation emitted by objects, while active infrared sensors emit their own infrared radiation and detect the reflection or absorption of that radiation by objects.

Passive infrared sensors are commonly used in motion detectors and security systems, where they can detect the presence of people or animals by sensing their body heat. Active infrared sensors are used in applications such as distance measurement, where they emit a beam of infrared radiation and measure the time it takes for the beam to be reflected back to the sensor.

Infrared sensors have a wide range of applications, from industrial automation to medical devices. They are particularly useful in environments where other types of sensors may not work, such as in low-light conditions or in the presence of smoke or dust.