An electronic ballast for energizing fluorescent lamps comprising a converter including a rectifier and a filter for converting an alternating source voltage into a direct current voltage, a network including first and second switching transistors, a tank circuit having a primary winding of a transformer, a secondary winding of the transformer for providing feedback of a portion of the voltage developed across the tank circuits and a bias circuit coupled between the opposite ends of the secondary winding and the emitters of the transistor for alternatively applying bias to the transistors, the network serving to convert a direct current voltage into an amplified sinusoidal voltage having a high frequency, and fluorescent lamps connected in a series configuration coupled across the primary winding.
D. Cronin, "Electronic Ballast Having Emitter Coupled Transistors and Bias Circuit Between Secondary Winding and the Emitters," U.S. Patents, Jan 1984.
Mechanical and Aerospace Engineering
Patent Application Number
01 Jan 1984