Photoresistors

Photoresistors (LDR s) are light-sensitive resistors. The resistance value can vary strongly depending on incident light. The dark resistance is typically within the range of MΩ, at 10 Lux however in the lower range of kΩ. The advantage by comparison with silicon photodiodes is in the spectral sensitivity of the LDRs. Whereas photodiodes are sensitive from 400 nm (blue) up to 1100 nm (infrared area) LDRs are only sensitive within the visible spectral range. LDRs are therefore particularly suitable as light sensors because these sensors do not detect the infrared radiation generally present in daylight that could lead to inaccurate measuring results.

Features

• Only pin types
• Different sensor sizes
• Hermetically sealed or on a ceramic substrate
• Sensitive within the visible spectral range

Applications

• Lamp control
• Inside lighting for motor vehicles