Photosensitive resistor is a photoconductive device made of semiconductor material, which is based on the internal photoelectric effect of semiconductor. The stronger the illumination, the lower the resistance value, and the bright resistance value can be as small as less than 1KΩ. When there is no light, the photosensitive resistance is in a high resistance state, and the dark resistance can generally reach 1.5MΩ. Photosensitive resistor has the advantages of small size, fast response speed and wide spectral response range, and is widely used in photoelectric control, automatic control, communication and other fields.
