What are the two basic types of infrared (IR) systems?

The two basic types of infrared (IR) systems are categorized primarily into active and passive systems. Active IR systems require an external power source to illuminate the area with infrared light, typically using light-emitting diodes (LEDs) to send out signals. The receiver then detects this modulated IR light reflected from objects, such as in remote controls or intrusion alarms.

On the other hand, passive IR systems do not emit infrared light themselves. Instead, they detect natural infrared radiation emitted by objects, primarily humans and animals, within their field of view. These systems are widely used in applications like motion sensors and thermal imaging cameras.

Understanding the distinction between active and passive systems is crucial for interpreting various applications in wireless communication, as each type has its benefits and ideal use cases based on power consumption and environmental factors.