Patent ID: 6225757
Filing Date: 2001-05-01
Classification: H05B

Abstract:
A combination ballast for powering either of first and second types of gas discharge lamps when connected to an ac power source comprising:a magnetic core;a primary coil wound on the magnetic core and coupled to a first end of a portion of the magnetic core, the primary coil adapted to be connected to the ac power source;a secondary coil coupled to a second end of the portion of the magnetic core, the secondary coil connected to a starting aid and to either the first or second types of gas discharge lamps, the starting aid adapted to start both types of gas discharge lamps;a capacitance circuit having a capacitance electrically connected between the primary coil and the secondary coil; andmeans for switching the capacitance of the capacitance circuit between a first predetermined value for operating the first type of gas discharge lamp and a second predetermined value for operating the second type of gas discharge lamp.