Dimming electronic ballast for true parallel lamp operation

摘要

A dimmable and program start electronic ballast is configured for powering one or more lamps in a true parallel configuration. An inverter driver is coupled to each gate of a pair of inverter switches and is responsive to at least a reference input signal and a feedback input signal to drive the inverter switches. The inverter circuit is effective thereby to generate an output voltage at an inverter output terminal between the pair of switches. One or more tank circuits are coupled in parallel, with a first end of each coupled to the inverter output terminal. Each tank circuit has a switching circuit as well as first and second output terminals on a second end which can receive a discharge lamp filament. A controller is configured to adjust a switching state for each of the one or more switching circuits and thereby enable or disable an associated tank circuit.