Full Description of
Light Dependent Resistor (LDR) Photoresistor –
A Light Dependent Resistor (LDR), also called a photoresistor, is a passive electronic component whose electrical resistance changes according to the intensity of light falling on its surface. As light intensity increases, the resistance of the LDR decreases; when light intensity decreases, its resistance increases.
Two metal terminals are connected at the ends
Enclosed in a transparent epoxy or glass package to allow light exposure
Electrical Characteristics (Typical)
Dark Resistance: 500 kΩ to 10 MΩ
Light Resistance: 200 Ω to 10 kΩ (depending on light intensity)
Operating Voltage: Low voltage (usually used in voltage divider circuits)
Response Time:
Rise time: 10–100 ms
Fall time: 50–300 ms
Spectral Response: Peak sensitivity around 520–560 nm (green light)