CdS Photoresistor Model 02 PUBLIC

This is the same as Carl's original circuit except that a
VCVS is used to derive the voltage across the Variable R,
ICDS.

This is the same as Carl's original circuit except that a VCVS is used to derive the voltage across the Variable R, ICDS.

That way, in a circuit using several CdS photoresistors, the expression is decoupled from the net names and only the V(K) part of the expression for has to be edited for each photoresistor. Note that, as Carl has implemented, the resistance of a CdS photoresistor is nominally inversely proportional to the illumination (usually expressed in Lux) the resistance vs Lux curve when plotted on a log-log graph, has some curvature or 'gamma'. This can be seen in Figure 1 of the datasheet here: http://www.ladyada.net/media/sensors/DTS_A9950_A7060_B9060.pdf

A definition of photoresistor gamma can be found in paragraph 3 of the Terminology section of this datasheet: http://ronja.twibright.com/datasheets/cds-resistor-pgm.pdf