Lighting system having a dimming color simulating an incandescent light
First Claim
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1. A lighting system, comprising:
- a light having a white light source and a color light source;
a control circuit controlling said white and color light sources in response to a brightness control signal corresponding to a selected brightness level of said light;
said control circuit pulsing said white light source and said color light source when said light is within a range of brightness levels, and in response to a change in said brightness control signal, said control circuit changing duty cycles of said white and color light sources, to alter a perceived color output of said light;
a switch controlling one of said white light source and said color light source;
a signal generator producing a periodic signal;
a comparator receiving said periodic signal from said signal generator and controlling said switch;
said comparator comparing a reference voltage to a signal voltage, said reference voltage relating to an aggregate current driving said white and color light sources and said signal voltage relating to said periodic signal; and
said switch being in one of an open state and a closed state when said reference voltage exceeds said signal voltage and being in an other of said open and closed states when said signal voltage exceeds said reference voltage.
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Abstract
A lighting system has a lighting fixture with a white light source and a color light source, a control circuit pulses the white and color light sources and changes relative duty cycles of the light sources to alter a color output of the lighting fixture, in response to a change in a control signal from a controller. A comparator compares a reference voltage relating to an aggregate current driving the light sources to a signal voltage relating to the periodic signal from a signal generator. The comparator controls a switch that controls one of the light sources. A duty cycle of the color light source can be vary inversely to a duty cycle of the white light source.
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Citations
31 Claims
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1. A lighting system, comprising:
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a light having a white light source and a color light source; a control circuit controlling said white and color light sources in response to a brightness control signal corresponding to a selected brightness level of said light; said control circuit pulsing said white light source and said color light source when said light is within a range of brightness levels, and in response to a change in said brightness control signal, said control circuit changing duty cycles of said white and color light sources, to alter a perceived color output of said light; a switch controlling one of said white light source and said color light source; a signal generator producing a periodic signal; a comparator receiving said periodic signal from said signal generator and controlling said switch; said comparator comparing a reference voltage to a signal voltage, said reference voltage relating to an aggregate current driving said white and color light sources and said signal voltage relating to said periodic signal; and said switch being in one of an open state and a closed state when said reference voltage exceeds said signal voltage and being in an other of said open and closed states when said signal voltage exceeds said reference voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A lighting system, comprising:
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a light having first and second light sources; a control circuit controlling said first and second light sources in response to a brightness control signal corresponding to a selected brightness level of said light; said control circuit alternately pulsing said first and second light sources when said light is within a range of brightness levels, whereby when said first light source is pulsed on, said second light source is off and when said second light source is pulsed on, said first light source is off; said control circuit changing duty cycles of said first and second light sources, in response to a change in said brightness control signal; and wherein duty cycles of said first and second light sources vary in a predetermined manner with respect to an aggregate current driving said first and second light sources. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A method of controlling a lighting system, comprising the steps of:
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providing a light having a white light source and a color light source; generating a control signal corresponding to a selected brightness level of said light; and pulsing said white light source and said color light source when said light is within a range of brightness levels, and in response to a change in the control signal, changing duty cycles of said white and color light sources, to alter a perceived color output of said light, as the brightness level of said light is changed by the control signal; wherein duty cycles of said white light source and said color light source vary in a predetermined manner with respect to an aggregate current driving said white light source and said color light source. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of controlling a lighting system, comprising the steps of:
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providing a light having first and second groups of LEDs, each group having at least one LED; providing a variable current to drive the first and second groups of LEDs; and alternately pulsing the first and second groups of LEDs; wherein duty cycles of the first and second groups of LEDs vary in a predetermined manner with respect to an aggregate current driving the first and second groups of LEDs. - View Dependent Claims (30, 31)
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Specification