Photodetector
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Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of appl
A photodetector salvaged from a CD-ROM drive. The photodetector contains three photodiodes, visible in the photo (the black squares arranged along the diagonal, in the very center).
Photoresistor
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A photoresistor is a passive component that decreases in resistance as a result of increasing illuminance on its sensitive surface, in other words, it exhibits photoconductivity. A photoresistor can b
Photodetector
…LEDs which are reverse-biased to act as photodiodes. See LEDs as photodiode light sensors. Photoresistors or Light Dependent Resistors (LDR) which change resistance according to light intensity. Normally the resistance of LDRs decreases with increasing…
LDR 1480405 6 7 HDR Enhancer 1
Three photoresistors with scale in mm
Large CdS photocell from a street light
The internal components of a photoelectric control for a typical USA streetlight. The photoresistor is facing rightwards and controls whether current flows through the heater which opens the main power contacts. At night, the heater cools, closing the power contacts, energizing the street light.