At dawn, the sensor uses the switch to automatically turn off the light and as soon as it starts getting dark at dusk, the photocell switch turns the light on. This automatic day and night switch ...

Or you can go back to basics and build this reflective RGB sensor from an LED and a photocell. The principle behind [TechMartian]’s approach is simplicity itself: shine different colored lights ...

For photometry (lux meters, exposure meters, closed-loop light control systems, etc.) we may wish to do this accurately, for many photocell applications we simply need to know if light is present or ...

Since the load circuit voltage was often line voltage (115 or 230VAC), the cadmium-sulfide photocell or LDR (Light Dependent Resistor) was the sensor of choice –while photo-transistors were available ...

According to the council the blame lies with a faulty photocell control switch which is used to measure the amount of daylight. But one villager claims they were never fitted in the first place.

The contract expired more than three years ago. Photocell sensors are placed on the street lights. Once natural light is detected by the sensor, the lights switch off and come on again after sunset.