Lighting control with season detect
AssigneeIllumination Dynamics LLC
InventorWade Lee
Life of this patent
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Abstract
An outdoor lighting control method and apparatus for use with an outdoor lighting fixture that automatically detects the changing length of the day and provides for automatically turning off the light after a shorter period of illumination during shorter summer nights and after a longer period of illumination during longer winter nights. The control method measures the elapsed time interval over which night sets in, for example, by sensing light levels characteristic of the onset of dusk and the onset of night and measuring the elapsed time between the two sensed light levels, and then automatically turns on the lighting fixture for nighttime operation for a duration that depends on the measured elapsed night-onset time.
Claims6
A method of controlling a duration for which an outdoor lighting fixture remains on at night, the lighting fixture including a light sensor for distinguishing day from night, said light sensor capable of distinguishing a range of ambient light levels, the method comprising:
- measuring the elapsed time between said sensor detecting a first ambient light level characteristic of the onset of dusk and a second ambient light level characteristic of the onset of night;
- and
- turning on said lighting fixture automatically at night for said duration determined by said elapsed time, said duration being monotonically increased as the measured elapsed time decreases.
Dependencies are inferred from the claim text.