High frequency driver for gas discharge lamp
AssigneeKoninklijke Philips Electronic, N.V.
InventorsJohannes Van Meurs, Dorota Pawelek
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Abstract
A high frequency driver for a gas discharge lamp is supplied with a DC voltage. The driver converts the input DC voltage to an AC voltage and supplies the AC voltage to a load, which comprises a gas discharge lamp, an inductor connected in series with the lamp and a capacitor connected in parallel to the lamp. The AC voltage has a first high frequency during ignition of the lamp and a second high frequency during normal operation of the lamp after its ignition. The first frequency is higher than the second frequency by a ratio of at least 2,2. By modulating the frequency of the AC voltage the ratio can be increased while still complying with EMI and RFI requirements.
Claims13
A high frequency driver for a gas discharge lamp, which is in series with an inductor and which has a capacitor connected in parallel to it, comprising an oscillator, which has DC input terminals for connecting to a DC source and AC output terminals for connecting to a load comprising the lamp, the inductor and the capacitor, the oscillator oscillating at a first high frequency during ignition of the lamp and the oscillator oscillating at a second high frequency during normal operation of the lamp after its ignition, with the first frequency being higher than the second frequency by a ratio of at least 2,2.
A method for driving a gas discharge lamp, which is in series with an inductor and which has a capacitor connected in parallel to it, by a driver which comprises an oscillator, which has DC input terminals for connecting to a DC source and AC output terminals for connecting to a load comprising the lamp, the inductor and the capacitor, the oscillator oscillating at a first high frequency during ignition of the lamp and the oscillator oscillating at a second high frequency during normal operation of the lamp after its ignition, with the first frequency being higher than the second frequency by a ratio of at least 2,2.
Dependencies are inferred from the claim text.