This LDR 3mm changes resistance with the change in the ambient light exposure on the surface of the sensor. LDR (Light Dependent Resistor) is a type of photocell which finds excellent use in light sensing device application, whether it is automatic outdoor light ON/OFF switch or Indoor automatic light switch.
The LDR 3mm sensor works best in both Light and dark regions. Light-dependent resistors or photoresistors are a staple of electronics. If you need a way to sense the level of ambient light then there is no easier way to do it. As the light on the sensor increases then the resistance across the two leads decreases.
Two Cadmium Sulphide (CDs) PhotoConductive Cells with spectral responses similar to that of the human eye. Cell resistance falls with increasing light intensity. Applications of this product include smoke detection, Automatic lighting control, batch counting, and burglar alarm systems.
To know more about photo-resistor, click here. WHAT IS PHOTO-RESISTOR??
 Analog Applications:
- Camera Exposure control
- Auto slide focus – dual cell
- Photocopy machines – the density of the toner
- Colorimetric Test Equipment
- Densitometer
- Electronics scales – dual cell
- Automatic gain control – modulated light source
- Automated Rear View Mirror
Digital Applications:
- Automatic Headlight Dimmer
- Nightlight control
- Oil burner flame out
- Streetlight control
- Absence / Presence (Beam breaker)
- Position sensor
