Light Dependent Resistor LDR 5mm Photoresistor
= Analog Light Sensor for Ambient Light Detection Projects =
The 5mm LDR is a lightdependent resistor that changes its resistance based on the intensity of light falling on its surface. It is a fundamental, lowcost analog sensor, making it a popular choice for applications like automatic lighting control, nightlights, and security systems .
Analog Light Sensing - Resistance varies with light intensity: decreases in bright light and increases in darkness .
Simple TwoTerminal Device Polarization-free; can be connected in any direction, simplifying circuit design .
Common applications include automatic streetlights, camera exposure control, and nightlights .
For best results with microcontrollers, use the LDR in a voltage divider circuit with a fixed resistor, and read the analog voltage .
= Technical Specifications (Typical) =
| Parameter | Value |
|---|
| Head Diameter | 5mm |
| Maximum Voltage | 150V DC |
| Maximum Power | 100mW |
| Operating Temperature | -30°C to +70°C |
| Spectral Peak | 540nm |
| Response Time | 20ms (Rise), 30ms (Down) |
| Light Resistance (10 Lux) | ~2kΩ to 200kΩ (varies by model) |
| Dark Resistance | ~0.5MΩ to 200MΩ (varies by model) |
Note: Light and dark resistance values vary significantly depending on the specific model .
= Key Features =
+Ambient Light Detection - Simple resistance change correlates to light level
+No Polarity Easy to connect in any direction for hasslefree prototyping
+Low Cost and Widely Available An affordable and standard component for lightsensing applications
== Common Applications ==
- Automatic night lights and streetlight controls
- Camera exposure control and automatic brightness adjustment
- Presence/Absence detection (beam breaker systems)
- Light-sensitive alarms and smoke detectors
- Solar-powered lighting systems
Versatile and Reliable - A staple component for basic light detection in electronics projects.
Arduino Compatible - Easily interfaces with analog inputs using a voltage divider .
√ Widely available in packs of 10, 20, or more
√ Through-hole design for breadboard and PCB use
