Programmable control elements for illumination systems
First Claim
Patent Images
1. A programmable current control device for an illumination system, the device comprising:
- a first connection point for receiving information representative of a desired output current level;
a memory element for storing the information representative of the desired output current level received at the first connection point, wherein the memory element is nonvolatile, whereby the memory element retains the information without application of power to the memory element;
a second connection point and a third connection point for electronically connecting to at least a portion of the illumination device; and
a control circuit configured to maintain an applied current that is ±
10% of the desired output current level, between the second and third connection points, by (i) receiving a reference voltage representative of the desired output current level from the memory element, (ii) applying the applied current to the at least a portion of the illumination device via the second and third connection points, (iii) receiving a resulting feedback voltage from the at least a portion of the illumination device, (iv) adjusting the applied current to reduce a difference between the feedback voltage and the reference voltage, and (v) repeating steps (ii)-(iv), wherein the control circuit comprises an operational amplifier, a first transistor, and a second transistor,wherein;
the operational amplifier has (i) a first input configured to receive the reference voltage, (ii) a second input configured to receive the feedback voltage, (iii) an output configured to output a signal representative of the difference between the feedback voltage and the reference voltage to a base of the first transistor, (iv) a first terminal for receiving input power, and (v) a second terminal electrically coupled to ground,the first transistor is coupled to the output of the operational amplifier, and a collector of the first transistor drives a base of the second transistor, andthe first and second transistors are configured to receive the signal from the output of the operational amplifier and adjust the applied current to reduce the difference between the feedback voltage and the reference voltage.
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Abstract
In accordance with various embodiments, a programmable current control device for an illumination system receives information representative of a desired output current level, stores information representative of the desired output current level, and maintains the desired output current level for at least a portion of the illumination system.
22 Citations
26 Claims
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1. A programmable current control device for an illumination system, the device comprising:
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a first connection point for receiving information representative of a desired output current level; a memory element for storing the information representative of the desired output current level received at the first connection point, wherein the memory element is nonvolatile, whereby the memory element retains the information without application of power to the memory element; a second connection point and a third connection point for electronically connecting to at least a portion of the illumination device; and a control circuit configured to maintain an applied current that is ±
10% of the desired output current level, between the second and third connection points, by (i) receiving a reference voltage representative of the desired output current level from the memory element, (ii) applying the applied current to the at least a portion of the illumination device via the second and third connection points, (iii) receiving a resulting feedback voltage from the at least a portion of the illumination device, (iv) adjusting the applied current to reduce a difference between the feedback voltage and the reference voltage, and (v) repeating steps (ii)-(iv), wherein the control circuit comprises an operational amplifier, a first transistor, and a second transistor,wherein; the operational amplifier has (i) a first input configured to receive the reference voltage, (ii) a second input configured to receive the feedback voltage, (iii) an output configured to output a signal representative of the difference between the feedback voltage and the reference voltage to a base of the first transistor, (iv) a first terminal for receiving input power, and (v) a second terminal electrically coupled to ground, the first transistor is coupled to the output of the operational amplifier, and a collector of the first transistor drives a base of the second transistor, and the first and second transistors are configured to receive the signal from the output of the operational amplifier and adjust the applied current to reduce the difference between the feedback voltage and the reference voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An illumination system comprising:
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first and second power conductors; a plurality of light-emitting strings, each light-emitting string having a first end electrically coupled to the first power conductor and a second end electrically coupled to the second power conductor, wherein the power conductors supply power to the light-emitting strings; and one or more programmable current control devices each configured to supply a desired output current level to one or more of the light-emitting strings, wherein each programmable current control device comprises; a first connection point for receiving information representative of the desired output current level, a memory element for storing the information representative of the desired output current level received at the first connection point, wherein the memory element is nonvolatile, whereby the memory element retains the information without application of power to the memory element, a second connection point and a third connection point electronically coupled to the one or more light-emitting strings, and a control circuit configured to maintain an applied current that is ±
10% of the desired output current level, between the second and third connection points, by (i) receiving a reference voltage representative of the desired output current level from the memory element, (ii) applying the applied current to the at least a portion of the illumination device via the second and third connection points, (iii) receiving a resulting feedback voltage from the at least a portion of the illumination device, (iv) adjusting the applied current to reduce a difference between the feedback voltage and the reference voltage, and (v) repeating steps (ii)-(iv), wherein the control circuit comprises an operational amplifier, a first transistor, and a second transistor, and wherein;the operational amplifier has (i) a first input configured to receive the reference voltage, (ii) a second input configured to receive the feedback voltage, (iii) an output configured to output a signal representative of the difference between the feedback voltage and the reference voltage to a base of the first transistor, (iv) a first terminal for receiving input power, and (v) a second terminal electrically coupled to ground, the first transistor is coupled to the output of the operational amplifier, and a collector of the first transistor drives a base of the second transistor, and the first and second transistors are configured to receive the signal from the output of the operational amplifier and adjust the applied current to reduce the difference between the feedback voltage and the reference voltage. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification