5mm 5528 LDR Light Dependent Resistor (5pcs)

The 5mm 5528 LDR is a 5528-type light dependent resistor (photoresistor), sold in a pack of 5. Its resistance is high in the dark and falls as the light gets brighter, so together with one fixed resistor it becomes a simple light sensor for an Arduino or ESP32 analog input. It is a favourite part for automatic lights, light meters and STEM experiments.

5mm 5528 LDR Specifications

• Type: CdS photoconductive cell (LDR), no polarity
• Diameter: 5 mm
• Dark resistance: about 1 MΩ
• Light resistance: tens of kΩ in dim light, falling to a few kΩ in bright light
• Peak sensitivity: 540 nm (green light, close to the response of the human eye)
• Maximum voltage: 150 V DC
• Maximum power: 100 mW
• Response time: about 20 ms rise, 30 ms fall
• Pack size: 5 pieces

5mm 5528 LDR Applications

• Automatic night lights and street-light models
• Measuring light level with an Arduino analog input
• Light-seeking and line-following robots
• Dusk-to-dawn switches with a transistor or comparator
• Science classes and STEM projects

What's in the Box

• 5 × 5 mm 5528 LDRs

Tip: Build a voltage divider: connect the LDR from 5 V to the analog pin and a 10 kΩ resistor from the analog pin to GND. The reading then rises as the light gets brighter.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.