HC-SR501 auto-senses light for various applications (in house, basement, outdoor, warehouse, garage, etc,) for ventilator control, alarm, etc.

Features

Automatic infrared detection (LHI778 probe design)
Output goes high when objects enter the sensing range, and automatically returns to low when object leaves
Optional photosensitive control
Optional temperature compensation
Trigger mode jumper
L: Non-repeatable / delay mode: sensor goes low after the delay, regardless of the presence of the object.
H: Repeatable: sensor stays high as long as any object is detected during the delay time.
Wide operating voltage range
Micro-amp power
Output high signal: easy to achieve docking with the various types of circuit.

Specifications

Voltage	4.8 V – 20 V
Current (idle)	<50 µA
Logic output	3.3 V / 0 V
Delay time	0.3 s – 200 s, custom up to 10 min
Lock time	2.5 s (default)
Trigger	repeat : L = disable , H = enable
Sensing range	<120 °, within 7 m
Temperature	– 15 ~ +70 °C
Dimension	32 x 24 mm screw-screw 28 mm, M2 Lens diameter: 23 mm