Lighting space controller
First Claim
1. 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; and
error 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.
1 Assignment
0 Petitions
Accused Products
Abstract
An illumination control system uses two photocells, one directed toward an illuminated lamp and the other directed from the ceiling downwardly into the illuminated zone. A feedback signal is derived from the two photocell signals and a reference intercept signal. The feedback signal and a reference set point signal are input into an error amplifier. The error amplifier generates a control signal for setting the illumination in controlled lamps. The photocell signals are variously scaled to provide balancing between them and matching with the intercept signal. Scaling factors and intercept signal level arc set in a calibration procedure that establishes feedback circuit response consistent with a design set point transfer function.
77 Citations
22 Claims
-
1. 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; and error 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. A lighting control system for maintaining illumination at selected levels at a first location within a space that is illuminated by at least first and second groups of lamp means the outputs of which are controlled by associated lamp drivers that are responsive to respective first and second control signals, the system comprising:
-
a first illumination sensor for sampling the illumination at a second location within the space and generating a first illumination signal, the illumination at the second location including illumination produced by the lamp means; a second illumination sensor for sampling the illumination at a third location within the space and generating a second illumination signal, the third location being distinct from the second location; a feedback circuit comprising first signal scaling means for scaling the first illumination signal by a first gain factor, second signal scaling means for scaling the first and second illumination signals by a second gain factor, and signal addition means, the first and second signal scaling means and the signal addition means being adapted for producing a composite signal representative of the sum of the scaled first and second illumination signals, an intercept signal generation means for generating an intercept signal having a selected level, and signal subtraction means for producing a feedback signal representative of the difference between the composite signal and the intercept signal; a third illumination sensor for generating a third illumination signal representative of the illumination at the first location; a first communication module for transmitting a communication signal representative of the third illumination signal; a calibration memory for storing coded instructions for setting the first and second gain factors and the intercept signal level; a calibration circuit coupled to the calibration memory, the first and second scaling means, and the feedback circuit, and responsive to the communication signal representative of the third illumination signal for adjusting the first and second gain factors and the intercept signal level; a second communication module coupled to the first communication module and the calibration circuit for transmitting the communication signal to the calibration circuit, and adapted to receive a key for enabling the calibration circuit to adjust the first and second gain factors and the intercept signal level; offset generation means, responsive to the calibration circuit, for biasing the feedback signal by a positive amount sufficient for preventing the feedback signal from becoming negative during adjustment of the first and second gain factors; a set point generator for generating a set point signal having a value that corresponds to the selected illumination level; a manually operable local controller coupled to the set point generator for adjusting the set point signal value; a remote controller coupled to the set point generator for transmitting a control signal to the set point generator for adjusting the set point signal value; error amplifier means responsive to the feedback signal and the set point signal for producing a base control signal appropriate for producing lamp outputs that maintain the illumination at the selected level at the first location, the base control signal having a maximum value corresponding to a fully dimmed lamp means condition; a first source producing a high signal having a value greater than the maximum value of the base control signal, the high signal value corresponding to a lamp means OFF condition; first and second switch means each coupled to the error amplifier means and the first source, the first and second switch means being operable for outputting, as respective first and second control signals, either the base control signal or the high signal, for selectively turning the first and second groups of lamp means to OFF; a second source producing a low signal having a level corresponding to full lamp means power; third switch means coupling the output of the first switch means to the second source and operable for setting the level of the first control signal to the level of the low signal for controlling the lamp drivers to fully power the associated lamp means; and fourth switch means coupling the output of the second switch means to the second source and operable for setting the level of the second control signal to the level of the low signal for controlling the lamp drivers to fully power the associated lamp means.
-
Specification