A photocell is a circuit element inside the ambient light sensor (ALS) that converts incident radiant energy into an electrical signal for daylight harvesting or dusk-to-dawn control. It's also referred to as a photosensor or photocontrol which, however, technically describes the whole sensing system. A typical photosensor. The role of electric lighting in daylighted spaces, regardless of whether they're indoor or outdoor areas, is to complement daylight during daytime and deliver the required illuminance. Daylighting control strategies may be implemented using “open loop” or “closed loop” systems. In an open-loop control system, the photosensor. Photocells employ varying mechanisms for daylight detection. Photoemissive detection is based on the photoelectric effect, in which electrons are emitted from the surface of, generally, a. Selection of photocells for daylighting applications should give consideration to a variety of criteria which can include sensitivity, spectral response, quantum efficiency, speed of response, slope characteristics, resistance.
