PGM CDS Photoresistors TOKEN CDS Light-Dependent Photoresistors Light-Dependent Photoresistors for Sensor Applications Preview The cadmium sulfide (CdS) or light dependent resistor (LDR) whose resistance is inversly dependent on the amount of light falling on it, is known by many names including the photo resistor, photoresistor, photoconductor, photoconductive cell, or simply the photocell. A typical structure for a photoresistor uses an active semiconductor layer that is deposited on an insulating substrate. The semiconductor is normally lightly doped to enable it to have the required level of conductivity. Contacts are then placed either side of the exposed area. The photo-resistor, CdS, or LDR finds many uses as a low cost photo sensitive element and was used for many years in photographic light meters as well as in other applications such as smoke, flame and bur glar detectors, card readers and lighting controls for street lamps. Providing design engineers with an economical CdS or LDR with high quality performance, Token Electronics now offers commercial grade PGM photoresistor. Designated the PGM Series, the photoresistors are available in 5mm, 12mm and 20mm sizes, the conformally epoxy or hermetical package offer high quality performance for applications that require quick response and good characteristic of spectrum. Token has been designing and manufacturing high performance light dependent resistors for decades. Our product offerings are extensive and our experience with custom photoresistor is equally extensive. Contact us with your specific needs. Features - Quick Response - Reliable Performance - Epoxy or hermetical package - Good Characteristic of Spectrum Applications - Photoswitch - Photoelectric Control - Auto Flash for Camera - Electronic Toys, Industrial Control Version 2010 01 of 03 PGM CDS Photoresistors TOKEN Terminology Light Resistance : Sensitive surface Measured at 10 lux with standard light A Electrodes Ceramic substrate (2854K-color temperature) and 2hr. preillumination at 400-600 lux prior testing. Resin Encapsulation Conducting resin Dark Resistance : Measured at 10th seconds after closing 10 lux. Lead wires Gamma characteristic : Under 10 lux and 100 lux and given by = log(R10/R100) / log(100/10) = log(R10/R100) R10, R100: resistance at 10 lux and 100 lux. The tolerance of is 0.1. CdS 100 Pmax : Max. power dissipation at ambient 80 CdSe temperature of 25C.At higher ambient 60 temperature,the maximum power permissible Cd(S.Se) may be lowered. 40 20 Vmax : Max. voltage in darkness that may be 0 applied to the device continuously. 400 500 600 700 800 900 1000 Wavelength(nm) Spectral peak : Spectral sensitivity of photoresistors depends on the wavelength of light they are exposed to and in accordance with figure Spectral Response. The tolerance of spectral peak is 50nm. Version 2010