Abstract: A luminaire diagnostic system including a lamp and a photocontroller for automatically turning the lamp on during periods of darkness and off during periods of daylight wherein the photocontroller includes detector circuitry for detecting the load drawn by the lamp, a microprocessor, responsive to detected load and programmed to predict a condition of the lamp such as a cycling event and/or lamp out condition based on the load drawn by the lamp, and an indicator such as a visual alarm for indicating the occurrence of the condition detected and/or a transmitter for transmitting the detected condition to a remote location. Also, upon cycle detection, the lamp may be turned off to prevent damage to fixture components.

Abstract: A photoelectric load control system for applying a.c. power to a street light as a function of ambient light level includes switching means for selectively applying a.c. power to a street light for turning the street light on and off; a trigger circuit having two states, a first state which actuates the switching means to turn on the street light and a second state which actuates the switching means to turn off the street light; means for biasing the trigger circuit into one of the states; and photoelectric sensing means for varying the bias on the trigger circuit to drive it into the other state in response to the ambient light level sensed by the photoelectric sensing means.