5mm Light Dependent Resistor (LDR)

5 mm Light Dependent Resistor (LDR) – a compact, photoconductive sensor that changes its resistance in response to ambient light. Housed in a rugged 5 mm through‑hole package, this discrete component is ideal for prototyping, classroom labs, and hobby projects that need a reliable way to detect brightness levels.

Students who work with this LDR will explore the fundamentals of optoelectronics, learn how light intensity translates into electrical signals, and practice building circuits such as automatic night lights, light‑controlled alarms, and simple photo‑reactive robots. The hands‑on experience reinforces concepts in physics (photons and conductivity), mathematics (Ohm’s law, logarithmic response curves), and programming (sensor reading and data logging).

Key Features

• Standard 5 mm diameter, lead‑spaced for easy breadboard insertion
• Wide resistance range: ~10 kΩ (bright) to >1 MΩ (dark)
• Fast response time (< 5 ms) for real‑time projects
• Low cost, high durability, and compatible with most voltage levels (5–30 V)

Because it bridges light, electricity, and code, the LDR is a perfect entry point for STEAM education. It encourages interdisciplinary problem‑solving, sparks curiosity about how everyday devices sense their environment, and provides a tangible link between theory and real‑world applications, all while fitting seamlessly into any electronics kit or curriculum.