Ballast circuit with a japped transformer flyback converter providing driving energy for start, glow and run modes of a lamp

摘要

Circuit arrangements generate start, glow, and/or run signals to be applied to and for operating a DC arc discharge lamp. A first circuit arrangement provides start, glow, and run signals. The first circuit arrangement includes a tapped transformer flyback converter circuit for combining the start and glow functions; a buck/boost converter for providing the run function; and blocking diodes for providing a blocking function for the glow circuit during the start and run modes, and further for providing a blocking function for the run circuit during the start and glow modes. A second circuit arrangement provides start and glow functions, and includes a tapped transformer flyback converter circuit for combining the start and glow functions; and a blocking diode for providing a blocking function for the glow circuit during the start mode. A third circuit arrangement includes a buck/boost converter for providing glow and run functions, and further includes an inductive storage element, such as an inductor. A fourth circuit arrangement includes a single buck/boost converter for providing start, glow, and run signals, and further includes an inductive storage element, such as an inductor. In all of the circuit arrangements, a switching device controls energy transferred through the inductive storage element, which is either a tapped transformer or an inductor. A measurement and control circuit measures a voltage and provides a control signal in response thereto, for controlling the switching device.