20mm CdS Photoresistor LDR Light Sensor
Prices updated: 13 Oct 2026
Compare prices
| Store | product | Price | View in store |
|---|---|---|---|
 Makers ElectronicsCheapest | GL20528 Photoresistor Sensor LDR 5-10KΩ 20mm | 20 EGP | View in store |
 RAM Electronics | LDR Big Size 20mm Photoresistor (CDS) | 35 EGP | View in store |
 Microohm | 20mm Light Sensitive Photoresistor LDR | 35 EGP55 | View in store |
Price history
Lowest daily price, last 90 days
Lowest price recorded: 20 EGP
About this product
A 20mm cadmium sulfide (CdS) photoresistor whose resistance decreases as light intensity increases. It is used for detecting light and darkness in night lights, automatic lighting and Arduino projects through a voltage divider circuit.
Specifications
- Type
- CdS photoresistor (LDR)
- Diameter
- 20 mm
- Resistance behavior
- Decreases as light increases
- Typical use
- Light and darkness sensing
Frequently asked questions
What is the price of 20mm CdS Photoresistor LDR Light Sensor in Egypt?
20mm CdS Photoresistor LDR Light Sensor currently costs between 20 and 35 EGP across 3 offers in Egypt.
Where can I buy 20mm CdS Photoresistor LDR Light Sensor in Egypt?
20mm CdS Photoresistor LDR Light Sensor is available from Makers Electronics, RAM Electronics, and Microohm. Compare the offers above to find the best price.
How do I read this LDR with an Arduino?
Build a voltage divider by connecting the LDR in series with a fixed resistor (commonly 10kΩ) between 5V and GND, then read the midpoint with an analog input pin using analogRead().
Is an LDR suitable for accurate light measurement?
No. LDRs respond slowly and their resistance is non-linear with light, so they are best used for threshold detection such as switching a light on at dusk, not for precise lux measurement.
