Constant Lumen Output Control System
First Claim
1. A method of providing constant lumen output control to a lumen output device, comprisingdetermining a number of operating hours for a lamp,determining a number of lamp starts for the lamp,creating a degradation value by combining the number of operating hours and the number of lamp starts,forming an output ratio for outputting power to the lamp using the degradation value and a target lamp output, andsetting a reduced power level for the lamp using the output ratio
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Abstract
A constant lumen output control system for providing a constant lumen output throughout the life of a lamp at the mean or preset lumen level. The lumen con system (315) coupled to a lamp driver (310) initially reduces the power to the lamp (330) to prevent the lamp from being operated at power levels that result excess mean or preset lumen levels. With increased lamp usage, the lumen control system gradually increases power to the lamp to compensate for lamp lumen depreciation due to light-reducing mechanisms. By compensating for lamp lumen depreciation the lamp is operated at a constant mean or preset lumen output throughout the life of the lamp.
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Citations
35 Claims
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1. A method of providing constant lumen output control to a lumen output device, comprising
determining a number of operating hours for a lamp, determining a number of lamp starts for the lamp, creating a degradation value by combining the number of operating hours and the number of lamp starts, forming an output ratio for outputting power to the lamp using the degradation value and a target lamp output, and setting a reduced power level for the lamp using the output ratio
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8. A method of providing constant lumen output control to a lumen output device, comprising
determining a stabilized lamp operating voltage for a lamp, determining a number of lamp starts for the lamp, creating a degradation value by combining the stabilized lamp operating voltage and the number of lamp starts, forming an output ratio for outputting power to the lamp using the degradation value and a target lamp output, and setting a reduced power level for the lamp using the output ratio
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15. A lumen output control circuit, comprising
a timer for measuring a number of operating hours for a lamp, a counter for measuring a number of lamp starts for the lamp, a processor for processing a plurality of light degradation equations and output ratios based on the number of operating hours and the number of lamp starts, and a non-volatile storage device for storing lamp information and lamp constants
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20. A lumen output control circuit, comprising
means for determining a stabilized lamp operating voltage for a lamp, a counter for measuring a number of lamp starts for the lamp, a processor for processing a plurality of light degradation equations and output ratios based on the stabilized lamp operating voltage for the lamp and the number of lamp starts for the lamp, and a non-volatile storage device for storing lamp diagnostic information and lamp constants
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24. A ballast, comprising
a power supply for providing power to a lamp, a ballast control circuit connected to the power supply for controlling ballast operations, a sensing circuit for providing lamp feedback information to the ballast, and a lumen output control circuit connected to the power supply, the ballast control circuit, the lamp driver and the sensing circuit configured to adjust power input to the lamp from the ballast
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30. An illumination system, comprising
a plurality of ballasts, each ballast having a lumen output control circuit for adjusting power input to a lamp from the ballast thereby creating a constant lumen output from the lamp, and a plurality of lamps connected to the plurality of ballasts for providing illumination
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35. A method of providing constant lumen output control to a lumen output device, comprising
determining a peak re-ignition voltage for a lamp, calculating a root mean square of a lamp operating voltage, creating a degradation value by forming a ratio of the peak re-ignition voltage and the root mean square of the lamp operating voltage, forming an output ratio for outputting power to the lamp using the degradation value and a target lamp output, and setting a reduced power level for the lamp using the output ratio
Specification