Patent ID: 6025679
Filing Date: 2000-02-15
Classification: H05B

Abstract:
A lighting control system for maintaining illumination at a selected level at a first location within a space that is illuminated by a first set of at least one lamp means the output of which is controlled by a first group of at least a first lamp driver that is responsive to a first control signal, the system comprising:a first illumination sensor for generating a first illumination signal representative of the illumination at a second location within the space, the illumination at the second location including illumination produced by the lamp means;a second illumination sensor for generating a second illumination signal representative of the illumination at a third location within the space, the third location being distinct from the second location;a feedback circuit coupled to the first and second sensors for producing a feedback signal representative of the sum of the first and second illumination signals with the first illumination signal scaled relative to the second illumination signal;a set point generator for generating a set point signal that corresponds to the selected illumination level; anderror amplifier means responsive to the feedback signal and the set point signal for producing a base control signal appropriate for producing a lamp output that maintains the illumination at the selected level at the first location.