ADVANCED PHOTONIX Light Dependent Resistor (LDR)

The ADVANCED PHOTONIX Light Dependent Resistor (LDR) is a passive electronic component with a resistance that varies according to the intensity of ambient light, making it an essential sensor for numerous automation and control applications. It operates on a simple principle: its dark resistance is high, dropping significantly when exposed to light. This reliable and cost-effective component is housed in a robust TO-8 metal can package, ensuring durability and stable performance across a wide range of environments.

Key Features & Operation

This LDR is characterised by a high minimum dark resistance of 1 MΩ, ensuring minimal current flow in low-light conditions. Upon illumination, its resistance can fall to within a typical range around 17 kΩ, allowing for a clear and usable signal change. With a maximum voltage rating of 320V and a power rating of 500mW, it is suitable for a variety of circuit designs, from simple light-activated switches to more complex analogue light metering systems. The two-pin configuration allows for straightforward integration into printed circuit boards (PCBs) or prototyping setups.

Robust Construction & Specifications

Encased in a TO-8 package, the sensor offers excellent protection. It is designed to perform reliably in challenging conditions, with an operating temperature range from -60°C to +75°C. The compact dimensions make it easy to incorporate into space-constrained designs. Its consistent response and robust build make it a go-to choice for engineers and hobbyists seeking a dependable light-sensing solution.

Typical Applications

This versatile component is perfect for building light-sensitive circuits. Common uses include creating automatic night lights, street light controllers, camera exposure meters, and burglar alarm systems that trigger when a beam of light is broken. It is also widely used in solar-powered devices to detect daylight and in opto-c