Apparatus and method for discretionary adjustment of lumen output of light sources having lamp lumen depreciation characteristic compensation

摘要

A method, apparatus, and system for compensating for lamp lumen depreciation and providing selective discretionary lamp power adjustment, e.g., for lamp dimming. The method includes operating the lamp under rated wattage for a period towards the first part of operating life of the lamp. Operating wattage is increased at one or more later times. Energy savings are realized. The increases also restore at least some light lost by lamp lumen depreciation. The apparatus uses a timer to track operating time of the lamp. A few wattage changes made at spaced apart times can be made in a number of ways, including changing capacitance to the lamp, or using different taps on the lamp ballast. A component allows selective discretionary adjustment of electrical power or some other controlling factor to adjust light output (e.g. dim) the lamp.