High intensity discharge lamp magnetic/electronic ballast
AssigneeShafrir Romano
InventorsShafrir Romano, Dror Manor, Arkadi Nirenberg
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Abstract
A metal halide magnetic/electronic ballast with a compensation function for adjustment in autotransformer output voltage, which applies the compensation in various steps of voltage, to maintain the power constant. The metal halide ballast provides constant monitoring of the autotransformer input voltage, enabling the level to be stepped by triac switching. The triac switching is controlled by a switching control provided by a microcontroller. Less components are required, making the present invention simpler, less expensive to manufacture and more reliable.
Claims15
A magnetic/electronic ballast for an HID lamp comprising:
- a variable output voltage supply connected across an inductor and the lamp, for applying thereto a selected output voltage;
- a voltage sensor for measuring an input voltage to said voltage supply;
- a controller responsive to said measured input voltage to provide a switching signal;
- and
- a switching arrangement connected to said voltage supply for selecting an appropriate switching state in accordance with said switching signal,
- wherein said switching state is provided in order to maintain a relatively constant power through said lamp throughout its useful life.
A method for operating a magnetic/electronic ballast for an HID lamp comprising:
- providing a variable output voltage supply connected across an inductor and the lamp for applying thereto a selected output voltage;
- measuring an input voltage to said voltage supply;
- providing a switching signal in response to said measured input voltage;
- and
- selecting an appropriate switching state in accordance with said switching signal,
- wherein said switching state is provided in order to maintain a relatively constant power through said lamp throughout its useful life.
Dependencies are inferred from the claim text.