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 or photocontrol is comprised of a photocell along with a controller which implements the conversion and communication logic. It controls luminaire operation to achieve additional energy savings in response to the amount of natural daylight detected. A photocell can produce an electrical current or resistance proportional to the amount of light that strikes it. When the change in photocell illuminance exceeds an established threshold, a photosensor signal is generated to control either a directly interfaced luminaire or a group of luminaires that are network connected and designated with a common zone address. Following the trend towards the Internet of Things (IoT), photosensors are moving from lighting controls to IoT devices.
at the Open Lighting Product Directory (OLPD)
