This is a Pyrolectric sensor(PIR) module which developed for human body detection.Its is also called Motion Sensor.A PIR detector combined with a Fresnel lens are mounted on a compact size PCB together with an analog IC , and limited components to form the module. It detect the motion by detecting the changes in the IR levels emitted from the object.It can be used as motion detector for security systems or robotics. It works from 3.3 V to 5 V DC and gives TTL output which can be directly given to microcontroller or to relay through a transistor.

Features of PIR Motion Detection Sensor HC-SR501:

• Compact size (28 x 28 mm).
• Supply current : DC 5V - 20V (can design DC 3 V – 24 V).
• Current drain : 50 uA (Other choice : DC 0.8V - 4.5V; Current drain: 1.5 mA - 0.1 mA).
• Voltage Output : High / Low level signal ： 3.3 V High level signal (Other choice : Open - Collector Output).
• TTL output can be directly connected to micro controller or logic device.
• High sensitivity.
• Delay time：5 s - 18 minute.
• Blockade time：0.5 s – 50 s (acquiescently 0 seconds) Operation Temperature : - 15℃ -70℃.
• Infrared sensor : dual element , low noise, high sensitivity.
• Light sensor : CdS photocell .
• Range : In Between 10meters at an angle of ±15 degrees.

Applications of PIR Motion Detection Sensor HC-SR501:

• Range Finder.
• Distance Sensor.
• DIY projects for various Robot designs.

Also Searched as : HC-SR501, PIR detector