Discharge lamp operating circuit
AssigneeGeneral Electric Company
InventorsDavid W. Knoble, Don Morais
Life of this patent
Estimating the term…
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 a ballast inductor and a lamp across the supply circuit, an SCR switch connected across the inductor, a coasting diode across the inductor and lamp, and a control circuit connected to the switches for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle. The circuit produces pulse waveforms which provide optimum 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, first controlled switch means and inductance means connected in series across said power source, means for serially connecting a gaseous discharge lamp to said first controlled switch means and said inductance means, unidirectional conducting means connected across said series connected inductance means and said lamp connecting means, second controlled switch means coupled to said inductance means for stopping current flow to the gaseous discharge lamp and for storing magnetic energy in said inductance means while said controlled switch means is on, and control means coupled to said first and second controlled switch means for repetitively and sequentially 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, first controlled switch means, inductance means and a gaseous discharge lamp connected in series across said power source, unidirectional conducting means connected across said series connected inductance means and said gaseous discharge lamp, second controlled switch means coupled to said inductance means for stopping current flow to said gaseous discharge lamp and for storing magnetic energy in said inductance means while said second controlled switch means in on, and control means coupled to said first and second controlled swich means for repetitively and sequentially operating the same at predetermined intervals, whereby DC pulses are applied to said gaseous discharge lamp for operation thereof.
Dependencies are inferred from the claim text.