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US 4,749,913 AGranted
Operating circuit for a direct current discharge lamp
AssigneeGeneral Electric Company
InventorsKarl Stuermer, William M. Rucki, Spiro Vamvakas
Life of this patent
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Abstract
A power supply for a metal halide discharge lamp includes a circuit for applying a high voltage starting pulse to the arc tube of the lamp to initiate the discharge, a glow transition current to provide power transitioning the arc tube from its glow to its run mode, and a run power supply circuit to provide continuous controlled d-c current to the arc tube.
Claims4
A controlled power supply circuit for supplying d-c power to an arc discharge lamp comprising:
- means for applying a relatively high voltage d-c potential to the arc discharge lamp for a first predetermined relatively short time interval;
- means for first supplying a d-c electrical current at a first predetermined current level to said said arc discharge lamp for a second predetermined time interval;
- and
- means for supplying a d-c electrical increasing current to said arc discharge lamp until a predetermined high limit is reached, then supplying a d-c electrical decreasing current until a predetermined low limit is reached, and continuing in a cyclic manner said increasing and decreasing d-c current so as to establish an average d-c current to said arc discharge lamp.
1 more element
Dependencies are inferred from the claim text.