Discharge lamp operating circuit
AssigneeGeneral Electric Company
InventorsDavid W. Knoble, Daniel V. Owen
Life of this patent
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Abstract
Color properties of high pressure sodium vapor discharge lamps are improved by disclosed operating circuit for applying pulsed direct current to the lamp. The circuit comprises a direct current supply circuit, a transistor switch in series with the lamp and the primary of a transformer connected across the supply circuit, a diode in series with the secondary of the transformer connected across the supply circuit, and a control circuit connected to the transistor switch for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle. The circuit produces pulse waveforms which provide substantial color improvement in the lamp and makes efficient use of the energy supplied from the power source.
Claims16
A lamp operating circuit comprising, in combination, a direct current power source, controlled switch means across said power source, a transformer having a primary winding and a secondary winding, said primary winding in series with said controlled switch means, unidirectional conducting means in series with said secondary winding across said power source, means for connecting a gaseous discharge lamp in series with said controlled switch means and said primary winding, and control means coupled to said controlled switch means for repetitively operating the same at predetermined intervals, whereby DC pulses may be applied to the gaseous discharge lamp for operation thereof.
A lamp operating circuit comprising, in combination, a direct current power source, a first branch including controlled switch means across said power source, a second branch including unidirectional conducting means across said power source, a transformer having a primary winding in said first branch in series with said controlled switch means and a secondary winding in said second branch in series with said unidirectional conducting means, means for connecting a gaseous discharge lamp to said power source in series with at least one of said branches, and control means coupled to said controlled switch means for repetitively operating the same at predetermined intervals, whereby DC pulses may be applied to the gaseous discharge lamp for operation thereof.
Dependencies are inferred from the claim text.