Illumination device and method for independently controlling power delivered to a load from dimmers having dissimilar phase-cut dimming angles
First Claim
1. An illumination device, comprising:
- a dimmer coupled to an AC main and configured to produce a conduction angle between a minimum and maximum conduction angle;
a light emitting diode (LED) load coupled to receive a drive current proportional to a DC power supply current averaged over multiple cycles of the AC main; and
a power supply coupled between the dimmer and the LED load for producing the DC power supply current averaged over multiple cycles of the AC main and drawn from the AC main independent of changes to the duration of the conduction angle up to and including a maximum conduction angle the dimmer is capable of producing when the dimmer is fully on.
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Accused Products
Abstract
An illumination device and method are provided for controlling light emitting diodes (LEDs). The LEDs (specifically, the LED loads) are controlled, e.g., brightness and color of the LED loads, independent of a phase-cut dimmer applied to the AC mains feeding a DC power supply. The power supply is active dependent upon the duration of a conduction angle supplied from the dimmer. The power supply, however, produces drive currents that are independent from the conduction angle by using a two-stage power supply and a relatively slow and fast control loops that are controlled through a microprocessor based control circuit. Parameters stored in the control circuit are drawn by the microprocessor to control the two-stage power supply to produce the drive currents independent and decoupled from the conduction angle yet dependent on the controller parameters.
52 Citations
16 Claims
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1. An illumination device, comprising:
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a dimmer coupled to an AC main and configured to produce a conduction angle between a minimum and maximum conduction angle; a light emitting diode (LED) load coupled to receive a drive current proportional to a DC power supply current averaged over multiple cycles of the AC main; and a power supply coupled between the dimmer and the LED load for producing the DC power supply current averaged over multiple cycles of the AC main and drawn from the AC main independent of changes to the duration of the conduction angle up to and including a maximum conduction angle the dimmer is capable of producing when the dimmer is fully on. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An illumination device, comprising:
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a dimmer coupled to an AC main and configured to produce a conduction angle between a minimum and maximum conduction angle; a light emitting diode (LED) load coupled to receive a drive current proportional to a DC power supply current during a duration of the conduction angle; a power supply coupled between the dimmer and the LED load for producing the DC power supply current drawn from the AC main; a control circuit coupled to the power supply for adjusting the DC power supply current across a range that is dissimilar to what the dimmer can supply if the output of the dimmer is AC/DC converted and applied as the drive current; and wherein the range in magnitude of the DC power supply current can extend to less than what the dimmer can supply if the output of the dimmer is AC/DC converted and applied as the drive current. - View Dependent Claims (10, 11)
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12. An illumination device, comprising:
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a dimmer coupled to an AC main and configured to produce a conduction angle between a minimum and maximum conduction angle; a light emitting diode (LED) load coupled to receive a drive current proportional to a DC power supply current during a duration of the conduction angle; a power supply coupled between the dimmer and the LED load for producing the DC power supply current drawn from the AC main; a control circuit coupled to the power supply for adjusting the DC power supply current across a range that is dissimilar to what the dimmer can supply if the output of the dimmer is AC/DC converted and applied as the drive current; and wherein the magnitude of the DC power supply current and a duration of the DC power supply are each independent of the duration of the conduction angle.
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13. A method for supplying an AC main to a light emitting diode (LED) load, comprising:
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adjusting a dimmer coupled to the AC main between a minimum conduction angle and a maximum conduction angle; detecting the amount of DC power supply current drawn from the AC main between a range of the minimum and maximum conduction angle; and changing the amount of DC power supply current to a range of DC current that is independent and different from what the dimmer can supply via AC/DC conversion when the dimmer is set between the minimum and maximum conduction angle. - View Dependent Claims (14, 15, 16)
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Specification