LDR 18mm Light Dependent Resistor Photoresistor CdS Light Sensor High Sensitivity Through Hole (18mm LDR Sensor)

The 18mm LDR is a large size light dependent resistor designed for high sensitivity light detection. It changes its resistance based on incident light intensity and is widely used in automatic lighting and sensing circuits.

Key Features -

• 18mm large disc type photoresistor
• High sensitivity due to larger surface area
• Resistance decreases with increasing light intensity
• Passive component no external power required
• Simple 2 pin through hole mounting
• Stable and reliable performance

Specifications -

• Sensor type - light dependent resistor LDR
• Disc diameter - approx 18mm
• Light resistance - approx 5k ohm to 20k ohm typical
• Dark resistance - approx 0.5 mega ohm to several mega ohm
• Maximum voltage - approx 150V DC typical
• Power rating - approx 90mW to 200mW
• Spectral peak - approx 540nm to 560nm

Applications -

• Automatic street light and night lamp systems
• Light and dark activated switching circuits
• Solar lighting control systems
• Security and alarm detection systems
• Ambient light sensing in electronics

Pinout Configuration -

• Pin 1 - resistive terminal
• Pin 2 - resistive terminal

Working Principle -

The LDR operates on photoconductivity where resistance decreases as light intensity increases. When light falls on the semiconductor surface it generates charge carriers which increase conductivity and reduce resistance. In darkness the resistance becomes very high and in light it drops significantly enabling light sensing functionality.