18mm LDR Light Dependent Resistor Photoresistor (CdS Light Sensor, 1 Qty)

The 18mm LDR Light Dependent Resistor is a large diameter photoresistive sensor designed for high sensitivity ambient light detection. Featuring an 18mm disc type construction and a cadmium sulphide (CdS) photosensitive element, this LDR changes its electrical resistance according to the intensity of incident light. It is widely used in automatic lighting systems, light detection circuits, solar lighting controls and electronic automation projects.

The 18mm photoresistor operates by decreasing its resistance when exposed to increasing light intensity and increasing its resistance in low light or darkness. Its larger photosensitive surface provides a wider light collection area compared to smaller LDR sensors. As a passive component, it does not require an external power supply for its sensing mechanism. When connected in a voltage divider circuit, the LDR produces a variable voltage signal suitable for Arduino, microcontrollers and other electronic control circuits.

Key Features -

• 18mm large disc type Light Dependent Resistor (LDR)

• Cadmium sulphide photosensitive sensing element

• Large sensing surface for effective light detection

• Resistance decreases as light intensity increases

• High sensitivity to visible light

• Passive sensing component requiring no external power

• Simple 2 pin through hole construction

• Suitable for voltage divider and light detection circuits

• Ideal for automatic lighting and electronic automation projects

Specifications -

• Product Type: Light Dependent Resistor

• Sensor Type: Photoresistor

• Photosensitive Material: Cadmium Sulphide (CdS)

• Disc Diameter: Approximately 18mm

• Number of Pins: 2

• Light Resistance: Approximately 5K Ohm to 20K Ohm, Depending on Variant and Illumination

• Dark Resistance: Approximately 0.5M Ohm to Several M Ohm, Depending on Variant

• Maximum Operating Voltage: Typically Up to 150V DC, Depending on Variant

• Power Dissipation: Approximately 90mW to 200mW, Depending on Variant

• Spectral Peak Sensitivity: Approximately 540nm to 560nm

• Light Sensitivity: Visible Light

• Resistance Characteristics: Decreases with Increasing Light Intensity

• Output Type: Variable Resistance

• External Power Requirement: Not Required for Sensing Element

• Mounting Type: Through Hole

• Pack Quantity: 1 Qty (1 Piece)

Applications -

• Automatic street light control systems

• Light and dark activated switching circuits

• Automatic night lamps and lighting systems

• Solar lighting control systems

• Security and light detection alarm circuits

• Ambient light sensing in electronic equipment

• Arduino and microcontroller projects

• IoT and embedded electronics applications

• Light controlled automation systems