# US 2014/0197754 A1 · Lighting Control System and Method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197754 A1 - Document ID: US20140197754A1 - Status: Published application - Kind: A1 - Application number: 14/212,021 - Filed: 2014-03-14 - Published: 2014-07-17 - Earliest claimed: 2012-05-14 - Assignees: Usai, LLC - Inventors: Donald L. Wray - Web page: https://patentgrep.com/patent/US20140197754A1 ## CPC - H05B 45/10: Controlling the intensity of the light - H05B 45/40: Details of LED load circuits - H05B 45/3577: Emulating the dimming characteristics, brightness or colour temperature of incandescent lamps - H05B 45/37: Converter circuits - H05B 45/395: Linear regulators - H05B 45/325: Pulse-width modulation [PWM] - H05B 45/46: having LEDs disposed in parallel lines - Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A lighting system provides for control of the perceived color of the light emitted by the light fixture. The light fixture has two light sources, a control circuit pulses the two light sources and changes relative duty cycles of the light sources to alter a perceived color output of the lighting fixture, in response to a control signal. Duty cycles of the light sources are a function of the control signal. ## Claims ### Claim 1 A lighting system, comprising: first and second light sources each comprising a light emitting diode; the first light source being operable to generate light having a first color; the second light source being operable to generate light having a second color; a signal generator operable to generate a timing signal having a period; a color control operable to generate a color control signal to adjust a color output of the lighting system; a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources; throughout a first range of the color control signal, the controller being operable to alternately pulse the first and second light sources at high rates such that when the first light source is in one of the one and off states, the second light source is in an opposite one of the one and off states, and being operable to vary the duty cycles of the first and second light sources in a smooth and continuous manner as a function of the color control signal between zero (0) percent and one-hundred (100) percent, where a change in the duty cycle of the first light source is opposite and equal in magnitude to a change in the duty cycle of the second light source; throughout a second range of the color control signal different than the first range, the controller being operable to illuminate the first light source at a duty cycle of one-hundred (100) percent and to not illuminate the second light source; and throughout a third range of the color control signal different than the first and second ranges, the controller being operable to illuminate the second light source at a duty cycle one-hundred (100) percent and to not illuminate the first light source. ### Claim 2 (depends on 1) The lighting system of claim 1, comprising: a brightness control operable to control a brightness level of the lighting system independent of the color control; and the color control does not appreciably change the brightness level of the lighting system. ### Claim 3 (depends on 1) The lighting system of claim 1, comprising: the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and the color control signal being derived from the variable aggregate current. ### Claim 4 (depends on 1) The lighting system of claim 1, comprising: the controller being operable, in response to a change in the color control signal at a first rate, to change the duty cycles of the first and second light sources at a second rate slower than the first rate, to dampen a rate of change of the color output of the light system. ### Claim 5 (depends on 1) The lighting system of claim 1, comprising the color control including a dimmer providing a variable voltage output. ### Claim 6 A lighting system, comprising: first and second light sources; a color control operable to generate a color control signal to adjust a color output of the lighting system; a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources; throughout a first range of the color control signal, the controller being operable to alternately switch the first and second light sources between on and off states such that when the first light source is in one of the one and off states, the second light source is in an opposite one of the one and off states, and being operable to vary the duty cycles of the first and second light sources as a function of the color control signal between zero (0) percent and one-hundred (100) percent, where a change in the duty cycle of the first light source is opposite and equal in magnitude to a change in the duty cycle of the second light source. ### Claim 7 (depends on 6) The lighting system of claim 6, comprising: throughout a second range of the color control signal different than the first range, the controller being operable to illuminate the first light source for a duty cycle of 100 percent and to not illuminate the second light source; and throughout a third range of the color control signal different than the first and second ranges, the controller being operable to illuminate the second light source for a duty cycle of 100 percent and to not illuminate the first light source. ### Claim 8 (depends on 7) The lighting system of claim 7, comprising: a combined range of the color control signal consisting of the first, second and third ranges; and the first range being about eighty (80) to ninety (90) percent of the combined range. ### Claim 9 (depends on 6) The lighting system of claim 6, comprising: a brightness control operable to control a brightness level of the lighting system independent of the color control; and the color control does not appreciably change the brightness level of the lighting system. ### Claim 10 (depends on 6) The lighting system of claim 6, comprising: the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and the color control signal being derived from the variable aggregate current. ### Claim 11 (depends on 6) The lighting system of claim 6, comprising: the controller being operable, in response to a change in the color control signal at a first rate, to change the duty cycles of the first and second light sources at a second rate slower than the first rate, to dampen a rate of change of the color output of the light system. ### Claim 12 (depends on 6) The lighting system of claim 6, comprising: throughout the first range of the color control signal, the color output of the lighting system substantially following the Black Body Locus. ### Claim 13 A lighting system, comprising: first and second light sources, the first light source being operable to generate light having a first color, and the second light source being operable to generate light having a second color; a color control operable to generate a color control signal to adjust a color output of the lighting system; a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources; throughout a first range of the color control signal, the controller being operable to pulse the first and second light sources at high rates between on and off states, and being operable to smoothly and continuously vary the duty cycles of the first and second light sources as a function of the color control signal where a change in the duty cycle of the first light source is opposite to a change in the duty cycle of the second light source and such that the duty cycle of the first light source varies from a first high duty cycle to a first low duty cycle and the duty cycle of the second light source varies from a second high duty cycle to a second low duty cycle; throughout a second range of the color control signal different than the first range, the controller being operable to illuminate the first light source at the first high duty cycle; and throughout a third range of the color control signal different than the first and second ranges, the controller being operable to illuminate the second light source at the second high duty cycle. ### Claim 14 (depends on 13) The lighting system of claim 13, comprising: the first and second low duty cycles being zero (0) percent and the first and second high duty cycles being one-hundred (100) percent. ### Claim 15 (depends on 13) The lighting system of claim 13, comprising: a brightness control operable to control a brightness level of the light fixture independent of the color control; and the color control does not appreciably change the brightness level of the lighting system. ### Claim 16 (depends on 13) The lighting system of claim 13, comprising: the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and the color control signal being derived from the variable aggregate current. ### Claim 17 (depends on 13) The lighting system of claim 13, comprising: the controller being operable, in response to a change in the color control signal at a first rate, to change the duty cycles of the first and second light sources at a second rate slower than the first rate, to dampen a rate of change of the color output of the light system. ### Claim 18 A lighting system, comprising: first and second light sources; a signal generator operable to generate a timing signal having a period; a first control operable to generate a control signal to adjust an output of the lighting system; a controller coupled to the first control to receive the control signal, and coupled to the signal generator and the first and second light sources; throughout a first range of the control signal, the controller being operable to pulse the first and second light sources between on and off states and to vary the duty cycle of the first light source as a function of the control signal, between a first high duty cycle and a first low duty cycle; and throughout a second range of the control signal different than the first range, the controller being operable to illuminate the first light source at the first high duty cycle. ### Claim 19 (depends on 18) The lighting system of claim 18, comprising: throughout the first range of the control signal, the controller being operable to vary a duty cycle of the second light source as a function of the control signal, between a second high duty cycle and a second low duty cycle, where a change in the duty cycle of the second light source is opposite to a change in the duty cycle of the first light source; and throughout a third range of the control signal different than the first and second ranges, the controller being operable to illuminate the second light source at the second high duty cycle. ### Claim 20 (depends on 19) The lighting system of claim 19, comprising: throughout the first range of the control signal, the change in the duty cycle of the second light source is equal in magnitude to the change in the duty cycle of the first light source. ### Claim 21 (depends on 18) The lighting system of claim 18, comprising: throughout the first range the controller being operable to alternately pulse the first and second light sources between on and off states such that when the first light source is in one of the one and off states, the second light source is in an opposite one of the one and off states. ### Claim 22 (depends on 19) The lighting system of claim 19, comprising: throughout the first range the controller being operable to vary the duty cycles of the first and second light sources smoothly and continuously between the respective first and second high and low duty cycles. ### Claim 23 (depends on 19) The lighting system of claim 19, comprising: the first and second high duty cycles being one-hundred (100) percent; and the first and second low duty cycles being zero (0) percent. ### Claim 24 (depends on 19) The lighting system of claim 19, comprising: a combined range of the control signal consisting of the first, second and third ranges; and the first range being about eighty (80) to ninety (90) percent of the combined range. ### Claim 25 (depends on 18) The lighting system of claim 18, comprising: the first light source being operable to generate light having a first color; the second light source being operable to generate light having a second color; the first control being operable to change a color output of the lighting system; and a second control operable to control a brightness level of the lighting system independent of the first control. ### Claim 26 (depends on 25) The lighting system of claim 25, comprising; the first control comprising a dimmer providing a variable voltage output. ### Claim 27 (depends on 18) The lighting system of claim 18, comprising: the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and the control signal being derived from the variable aggregate current. ### Claim 28 (depends on 27) The lighting system of claim 27, comprising; the first control being a dimmer providing a variable voltage output. ### Claim 29 (depends on 18) The lighting system of claim 18, comprising: the controller being operable, in response to a change in the control signal at a first rate, to change the duty cycle of at least the first light source at a second rate slower than the first rate, to dampen a rate of change of the output of the light system. ### Claim 30 (depends on 18) The lighting system of claim 18, comprising: throughout the first range of the color control signal, the color output of the lighting system substantially following the Black Body Locus.