Abstract: A power circuit for at least one gas discharge lamp comprising a first filament and a second filament, the power circuit including an electronic driver circuit, preferably for generating a first alternating voltage between the first and second filament for starting up the gas discharge lamp and for generating a second alternating voltage between the first and second filament for having the gas discharge lamp burn after it has been started up, wherein the power circuit further includes an electronic heating circuit for, at least during generation of the second alternating voltage, generating a first current through the first filament for heating the first filament and/or generating a second current through the second filament for heating the second filament.

Abstract: A power circuit for at least one gas discharge lamp comprising a first filament and a second filament, the power circuit including an electronic driver circuit, preferably for generating a first alternating voltage between the first and second filament for starting up the gas discharge lamp and for generating a second alternating voltage between the first and second filament for having the gas discharge lamp burn after it has been started up, wherein the power circuit further includes an electronic heating circuit for, at least during generation of the second alternating voltage, generating a first current through the first filament for heating the first filament and/or generating a second current through the second filament for heating the second filament.

Abstract: An input dc-voltage, usually obtained from an AC-mains voltage through a pre-connected rectifier and Power Factor Corrector, is converted by a series connection of two power transistors to an ac-voltage, which, via an LC section is presented to a gas discharge lamp. For starting the lamp, the power transistors are switched with a frequency which is slightly higher than approximately one-third or one-fifth of the resonance frequency of the LC section. Circuits have been provided for limiting the output voltage, for limiting the lamp current and for stabilizing the lamp output. Safety circuits switch the power circuit off if the lamp does not ignite or if the lamp exhibits rectifying effect.