A device for activating machines as a box/carton or case passes a given reference point.

(n) a transducer used to detect and measure light and other radiations

A light-sensing device used to control fixtures and dimmers.

An opto-electronic device used to switch on infrared lighting at preset levels, and to switch from color to monochrome camera operation.

A device that detects levels of daylight and adjusts luminaires accordingly. It is often used with a street light to turn the light on at dusk and off at dawn.

Photoelectric cell; the light-sensitive component within a photosensor. The actual device might be a photodiode, a phototransistor, or a photoconductive cell. It is important to make a distinction bet [..]

A Photocell is an electronic device whose electrical output is directly proportional to the amount of light which it receives.

a device that converts light energy into electrical energy

A light-controlled variable resistor which has a light-to-dark resistance ratio of 1:1000.

See also Beam, Cell. Infrared devices that collect data from the course or track, sending instantaneous impulses to the timers.