Light emitting diode lamp and control circuit thereof
First Claim
1. A control circuit adapted for controlling an electric current through an LED of an LED lamp, comprising:
- a voltage regulator comprising an output terminal for coupling to an input end of the LED thereby providing the electric current to the LED and a feedback terminal;
a feedback circuit comprising an amplifier, the amplifier comprising an in-phase input end, an out-phase input end and an output end, the out-phase input end being adapted for coupling to an output end of the LED, the output end of the amplifier being connected to the feedback terminal of the voltage regulator; and
at least a photo-resistor being connected between the in-phase input end of the amplifier and ground;
wherein the at least a photo-resistor senses a change of a brightness level of an environment surrounding the LED lamp and has a resistance thereof increasing along with a decrease of the brightness level of the environment surrounding the LED lamp, the increase of resistance of the at least a photo-resistor being fed back to the voltage regulator via the amplifier, to thereby control the electric current to the LED to be increased so that an intensity of light output of the LED is increased.
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Accused Products
Abstract
A control circuit of an LED lamp includes a voltage regulator, at least a photo resistor and a feedback circuit. The voltage regulator includes an output terminal and a feedback terminal. The feedback circuit includes an amplifier having a first input end, a second input end and an output end. The LED lamp is connected between the first input end of the amplifier and the output terminal of the voltage regulator. The at least a photo resistor can sense a change of brightness level of an environment surrounding the LED lamp and a resistance of the at least a photo resistor increases along with a decrease of the brightness level. The change of resistance of the photo resistor is fed back to the voltage regulator via the amplifier, to thereby control an electric current flowing through the LED lamp.
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Citations
7 Claims
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1. A control circuit adapted for controlling an electric current through an LED of an LED lamp, comprising:
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a voltage regulator comprising an output terminal for coupling to an input end of the LED thereby providing the electric current to the LED and a feedback terminal; a feedback circuit comprising an amplifier, the amplifier comprising an in-phase input end, an out-phase input end and an output end, the out-phase input end being adapted for coupling to an output end of the LED, the output end of the amplifier being connected to the feedback terminal of the voltage regulator; and at least a photo-resistor being connected between the in-phase input end of the amplifier and ground; wherein the at least a photo-resistor senses a change of a brightness level of an environment surrounding the LED lamp and has a resistance thereof increasing along with a decrease of the brightness level of the environment surrounding the LED lamp, the increase of resistance of the at least a photo-resistor being fed back to the voltage regulator via the amplifier, to thereby control the electric current to the LED to be increased so that an intensity of light output of the LED is increased. - View Dependent Claims (2, 3)
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4. An LED lamp comprising:
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a voltage regulator comprising an output terminal and a feedback terminal; an amplifier comprising an in-phase input end, an out-phase input end and an output end, the output end of the amplifier being connected to the feedback terminal of the voltage regulator; at least one LED being connected between the out-phase input end of the amplifier and the output terminal of the voltage regulator; and at least a photo-resistor being connected between the in-phase input end of the amplifier and ground; wherein the at least a photo-resistor senses a change of a brightness level of an environment surrounding the LED lamp and has a resistance thereof increasing along with a decrease of the brightness level of the environment surrounding the LED lamp, and the increase of resistance of the at least a photo-resistor is fed back to the voltage regulator via the amplifier, to thereby control an electric current flowing through the at least one LED to be increased to increase an intensity of light output of the at least one LED. - View Dependent Claims (5, 6, 7)
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Specification