Introduction to LDR sensor

A  light dependent resistor (LDR) also called as photoresistor or photoconductor is basically a photo cell which works on the principle of ph0toconductivity.

It is used to detect the levels of lights.For example automatic street light, when the light intensity increases ,the resistance decreases and when their is low light level at that moment the Resistance of a LDR increases and small amount of current flow through it.

In LDR, resistor is the passive component whose resistance decreases when the intensity of light is decreases and this optoelectronic device is used in the light varying circuit & light and dark switching circuits.

Pin Description