Handson TechnologyUser GuideGL55 Series Photo Resistor (LDR) The Cadmium Sulfide (CdS) or Light Dependent Resistor (LDR) whose resistance is inversely dependent on the amount of light falling on it, is known by many names including the photo resistor, photoconductor, photoconductive cell, or simply the photocell. The photo- resistor finds many uses as a low cost photo sensitive element use in photographic light meters as well as in other applications such as smoke, flame and burglar, detectors, card readers and lighting controls for street lamps. SKU: SSR1021Brief Data: Light Resistance Range: 2~20KΩ. Refer to Table 1. Dark Resistance at 0 Lux: 1MΩ Min. Peak Spectral Response: 540nm. Typical Fall Time: 55ms. Typical Rise Time: 45ms. Operating Voltage Vmax: 100V. Power Rating Pmax: 100mW. Resistor Material: CdS (cadmium sulfide). Number of Pins: 2-pin Through Hole. Package Type: TO-18 Epoxy Resin. 1www.handsontec.com