Method and apparatus for dimming high intensity discharge lamps
AssigneeGeneral Electric Company
InventorsJanos Laszlo Sneider, Gergely Janos Ormandlaky
Life of this patent
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Abstract
A method for operating a HID lamp using a bi-power electromagnetic ballast. The method includes applying a full power level to the lamp to produce full brightness and applying a dimmed power level to the lamp to produce a dimmed brightness. The lamp may be dimmed by switching the lamp power from the full power level to the dimmed power level and then applying a full power pulse to the lamp. The dimmed power level is less than the full power level.
Claims20
A method for operating a HID lamp using a bi-power electromagnetic ballast, the method comprising:
- applying a full power level to the HID lamp to produce full brightness;
- applying a dimmed power level to the lamp to produce a dimmed brightness, wherein the dimmed power is less than the full power;
- and
- applying a full power pulse to the lamp to maintain the lamp in a dimmed state.
A bi-power electromagnetic ballast for driving a HID lamp, the ballast comprising:
- a ballasting power circuit configured to receive an AC input power and produce a lamp power;
- a dimming circuit coupled to the ballasting power circuit and configured to control the ballasting power circuit to produce the lamp power at a full power level or a dimmed power level, wherein the dimmed power level is less than the full power level;
- and
- wherein the dimming circuit is configured to dim the lamp by:
- switching the lamp power from the full power level to the dimmed power level;
- waiting a first period of time;
- switching the lamp power from the dimmed power level to the full power level;
- waiting a pulse time;
- and
- switching the lamp power from the full power level to the dimmed power level.
An electric lighting apparatus comprising:
- a bi-power electromagnetic ballast configured to receive an AC input power and produce a lamp power;
- and
- a HID lamp coupled to the electromagnetic ballast and configured to receive the lamp power,
- wherein the bi-power electromagnetic ballast is configured to:
- produce the lamp power at a full power level and a dimmed power level, wherein the full power level is greater than the dimmed power level, and
- wherein the electromagnetic ballast is configured to dim the HID lamp by:
- reducing the lamp power from the full power level to the dimmed power level;
- and
- applying a full power pulse to the HID lamp.
Dependencies are inferred from the claim text.