5mm LDR Sensor Photo-resistor Light Dependent Resistor Photo Cell Switch 2 Pin Leads For Automatic Headlight Dimmer Control Resistor

Specification:

• Qty: 5Pcs
• It requires less power to operate
• Quick Response
• Easy to use
• Generate high current
• Maximum Voltage (V-dc): 150V
• Maximum Power Consumption (mW): 100W
• Temperature (°C): -30 – +70°C
• Spectrum Peak Value (nm): 540 OD
• The limit test parameters:
• Bright Resistance (10Lux) (KΩ): < 45
• Dark Resistance (MΩ): > 200
• Application parameters reference value:
• Light resistance: < 8 k
• Dark resistance: > 20 mega-ohm
• 100¦Ë10: 0.6
• Response Time (ms): Up: 20/ Down: 30
• Light Resistance Characteristic: 3
• The length of the pins: > 2.5 CM/0.98″
• Material: Carbon
• Performance: General
• Shape: cylindrical
• Applications: burglar alarm circuit
• Size: 5mm

Applications:

• Camera Exposure Control
• Auto Slide Focus
• Photocopy Machines
• Colorimetric Test Equipment
• Densitometer
• Electronic Scales
• Automatic Gain Control
• Automated Rear View Mirror
• Automatic Headlight Dimmer
• Night Light Control
• Oil Burner Flame Out
• Street Light Control
• Absence / Presence (beam breaker)
• Position Sensor

This is a very small light sensor. A photocell changes (also called a photodetector, photo resistor, CdS or photoconductive cell) resistance depending on the amount of light it is exposed to. These little sensors make great ambient light triggers (when light in the room turns on, do something)

A light dependent resistor works on the principle of photo conductivity. Photo conductivity is an optical phenomenon in which the materials conductivity is increased when light is absorbed by the material. When light falls i.e. when the photons fall on the device, the electrons in the valence band of the semiconductor material are excited to the conduction band. These photons in the incident light should have energy greater than the band gap of the semiconductor material to make the electrons jump from the valence band to the conduction band. Hence when light having enough energy strikes on the device, more and more electrons are excited to the conduction band which results in large number of charge carriers. The result of this process is more and more current starts flowing through the device when the circuit is closed and hence it is said that the resistance of the device has been decreased. This is the most common working principle of LDR.

Light Dependent Resistor (LDR) 5mm LDR Stands for Light Dependent Resistor and its Resistivity varies with Incident Electromagnetic Radiations so, its resistivity is a function of Incident Electromagnetic Radiations or light. Other names of LDR are photo-resistor, Photoconductor, Photocell, and photo conducting cell
LDR is made of Semiconductor materials with high Resistance like Silicon or Germanium. It is a light-sensitive device, so this resistor has a different resistance value in day and night as given below
– Daylight: 5000Ω
– Dark: 20000000Ω