Patent ID: 8664872

Claim:
An apparatus for operating a gas discharge lamp, comprising: an electronic ballast having a plurality of switches arranged in a full bridge configuration, said full bridge configuration including a first inductance-capacitance network and a second inductance-capacitance network, said first inductance-capacitance network being for an igniter function controlled by less than all of said plurality of switches that are arranged in a half bridge configuration, said second inductance-capacitance network being for a buck inverter function controlled by all of said plurality of switches; and a controller, said controller controlling said full bridge configuration in said igniter function to ignite an arc between electrodes of a gas discharge lamp, said controller switching an operation of said electronic ballast from said igniter function after the arc is ignited between the electrodes of the gas discharge lamp to said buck inverter function to sustain the arc between the electrodes of the gas discharge lamp, wherein said controller controls said full bridge configuration to operate said buck inverter function in such a way that at least when the arc between the electrodes extinguishes, a swing voltage having a decreasing amplitude above and below a lamp voltage is generated across a first inductance of said first inductance-capacitance network over a plurality of periods to re-ignite the arc between the electrodes of the gas discharge lamp.