b: The on-off ratios (the ratio of conductivity with/without pseudo-sunlight) of the photoresistor devices. The higher the on-off ratio, the better the performance of the photoresistor.

[Fjord Carver] brings together an RGB LED and CdS Photoresistor to make a color sensor. Those Cadmium Sulfide lights sensors usually have a very wide swing of resistance when exposed to varying ...

He replace the variable resistor with a cadmium sulfide photoresistor (basically a variable resistor whose resistance depends on the intensity of light). Pulse-width modulation is used to adjust ...