Abstract: A system and method of controlling a lighting system is provided. Lamp insertion detectors are coupled to a ballast and detect when relamping occurs. The outputs of the lamp insertion detectors are coupled together to provide a single input of a timing circuit. The timing circuit generates an output having a predetermined duration. This timing circuit output is received by a ballast driver circuit, which causes the ballast to provide a high voltage to a lamp socket for a predetermined duration of the timing circuit output to ignite the new lamp.

Abstract: This disclosure describes embodiments of a lighting device with circuitry that can manage current and voltage levels across a plurality of fluorescent lamps. In one embodiment, the circuitry has cross-coupled inductors in series with a pair of lamp sockets. This configuration of components causes fluorescent lamps installed in the lamp sockets to generate substantially the same amount of light by drawing approximately equivalent current throughout the entire operable range of a dimmer control. The circuitry also includes a protection circuit with a winding magnetically coupled with the cross-coupled inductors and a control circuit that can cause impedance across the winding to change from a first impedance to a second impedance in response to operating conditions in the lamps. This feature avoids high operating voltages that can occur across the cross-coupled inductors when one of the fluorescent lamps is inoperable and/or removed from the lamp sockets.

Abstract: A system and method of controlling a lighting system is provided. Lamp insertion detectors are coupled to a ballast and detect when relamping occurs. The outputs of the lamp insertion detectors are coupled together to provide a single input of a timing circuit. The timing circuit generates an output having a predetermined duration. This timing circuit output is received by a ballast driver circuit, which causes the ballast to provide a high voltage to a lamp socket for a predetermined duration of the timing circuit output to ignite the new lamp.