DIMMING MULTIPLE LIGHTING DEVICES BY ALTERNATING ENERGY TRANSFER FROM A MAGNETIC STORAGE ELEMENT
First Claim
1. A circuit for powering two or more lighting devices, the circuit comprising:
- a first output terminal for providing a first output current or voltage to a first one of the lighting devices;
a second output terminal for providing a second output current or voltage to a second one of the lighting devices;
a first switching circuit coupled to an input power source;
a magnetic storage element coupled to the first switching circuit and having at least one winding, wherein the first switching circuit charges the magnetic storage element from the input power source during charging intervals; and
a second switching circuit coupled to the magnetic storage element for providing the first output current or voltage to the first output terminal and the second output current or voltage to the second output terminal during alternating flyback intervals following the charging intervals.
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Accused Products
Abstract
A single magnetic storage element is used to provide power to multiple lighting devices, which may be strings of light-emitting diodes (LEDs) of different color. A switching circuit controls alternating application of energy among the multiple lighting devices and another switching circuit may charge the primary winding to different energy levels to control the intensity of the multiple lighting devices. In particular, the multiple lighting devices may be controlled to provide a desired color profile while dimming the lighting devices, while requiring only a single magnetic storage element for supplying energy to the lighting devices.
23 Citations
28 Claims
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1. A circuit for powering two or more lighting devices, the circuit comprising:
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a first output terminal for providing a first output current or voltage to a first one of the lighting devices; a second output terminal for providing a second output current or voltage to a second one of the lighting devices; a first switching circuit coupled to an input power source; a magnetic storage element coupled to the first switching circuit and having at least one winding, wherein the first switching circuit charges the magnetic storage element from the input power source during charging intervals; and a second switching circuit coupled to the magnetic storage element for providing the first output current or voltage to the first output terminal and the second output current or voltage to the second output terminal during alternating flyback intervals following the charging intervals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An integrated circuit, comprising:
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an output terminal for supplying charging current to a magnetic storage element for supplying energy to two or more lighting devices coupled to the magnetic storage element; and a first switching circuit having an input coupled to an input power source and an output coupled to the output terminal for charging the magnetic storage element during charging intervals, wherein the energy is supplied to the two or more lighting devices during corresponding non-overlapping and alternating flyback intervals following the charging intervals, whereby application of the energy to the two or more lighting devices is alternated between the corresponding lighting devices. - View Dependent Claims (13, 14, 15, 16)
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17. A circuit comprising:
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a first output terminal for providing a first output current to a first string of light-emitting diodes having a first color; a second output terminal for providing a second output current to a second string of light-emitting diodes having a second color; and a power switching circuit having a magnetic storage element from which energy is alternatively supplied to the first output terminal during a first period and to the second output terminal during a second period not substantially overlapping the first period, whereby different current or voltages may be applied to the first output terminal and the second output terminal to control the relative intensity of light provided by the first string of light-emitting diodes and the second string of light-emitting diodes. - View Dependent Claims (18)
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19. A method of supplying power to multiple lighting devices, comprising:
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first controlling charging of a magnetic storage element during charging intervals; second controlling discharging of the magnetic storage element to alternate application of energy stored in the magnetic storage element between the multiple lighting devices during alternating flyback intervals following the charging intervals; first providing a first output current or voltage to a first one of the lighting devices during a first one of the flyback intervals; and second providing a second output current or voltage to a second one of the lighting devices during a second one of the flyback intervals. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification