HC-SR501 PIR Motion Sensor

Working Principle: The HC-SR501 sensor detects motion by sensing changes in infrared radiation emitted by objects within its detection range. It operates on the principle that warm objects emit infrared radiation, and when an object moves, it causes a change in the detected infrared radiation pattern.

Detection Range: The detection range of the HC-SR501 sensor can typically be adjusted using the onboard potentiometers. The range can vary but is often around 3-7 meters with a wide-angle detection pattern.

Operating Voltage: The sensor module typically operates at a voltage between 4.5V and 20V DC. It can be powered directly from a battery or an external power supply.

Output Signal: When motion is detected, the sensor outputs a digital signal on its OUT pin, typically going from LOW to HIGH. The signal duration depends on the duration of the detected motion and is adjustable.

Delay Time and Sensitivity: The HC-SR501 module allows you to adjust both the delay time and sensitivity using onboard potentiometers. The delay time determines how long the output signal remains high after motion is detected, while the sensitivity setting controls the detection range.