US 9,426,855 B2Granted

Multi-stage LED lighting systems

AssigneeAmerican Bright Lighting, Inc.

InventorsGeorge Lee, Stanley Chen

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Abstract

Multi-stage LED drivers and lighting systems are disclosed. The lighting system comprises a bridge rectifier receiving power from an AC power line source, two or more current limiting devices, and a string of LEDs having a corresponding number of LED lamps connected in electrical series. Each of the current limiting devices is coupled to and provides current to the corresponding LED. When the instantaneous voltage of the alternating current source is near zero volts, no significant current flows through the string of LEDs. As the instantaneous voltage from the bridge rectifier increases beyond the forward voltages of the LEDs in the string, the current limiting devices energize and provide current to the corresponding LEDs as well as the LEDs connected to the cathode of the corresponding LED. The equivalent circuits of the lighting system vary throughout the power cycle of the AC line power source.

Claims20

Dependent claims

An LED lighting system comprising:

a bridge rectifier directly coupled to an AC line power source and providing a rectified signal, the AC line power source having a power cycle;
a string of LEDs comprising a first, second, and third set of LEDs, the cathodes of the first set of LEDs directly, electrically connected to the anodes of the second set of LEDs, the cathodes of the second set of LEDs directly, electrically connected to the anodes of the third set of LEDs, the cathodes of the third set of LEDs connected to the bridge rectifier;
a first current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the first current limiting device coupled directly to the anode of the first set of LEDs and configured to provide a first limited current to the first, second, and third set of LEDs during a first portion of the power cycle;
a second current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the second current limiting device coupled directly to the anode of the second set of LEDs and configured to provide a second limited current to the second and third set of LEDs during a second portion of the power cycle;
and,
a third current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the third current limiting device coupled directly to the anode of the third set of LEDs and configured to provide a third limited current to the third set of LEDs during a third portion of the power cycle.

3 more elements

An LED lighting system comprising:

a bridge rectifier directly coupled to an AC line power source and providing a rectified signal, the AC line power source having a power cycle;
a string of LEDs comprising a first, second, third, and fourth set of LEDs, the cathodes of the first set of LEDs directly, electrically connected to the anodes of the second set of LEDs, the cathodes of the second set of LEDs directly, electrically connected to the anodes of the third set of LEDs, the cathodes of the third set of LEDs directly, electrically connected to the anodes of the fourth set of LEDs, the cathodes of the fourth set of LEDs connected to the bridge rectifier;
a first current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the first current limiting device coupled directly to the anode of the first set of LEDs and configured to provide a first limited current to the first, second, third, and fourth set of LEDs during a first portion of the power cycle;
a second current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the second current limiting device coupled directly to the anode of tile second set of LEDs and configured to provide a second limited current to the second, third, and fourth set of LEDs during a second portion of the power cycle;
and,
a third current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the third current limiting device coupled directly to the anode of the third set of LEDs and configured to provide a third and fourth limited current to the third set of LEDs during a third portion of the power cycle;
a fourth current limiting device coupled directly to the bridge rectifier receiving the rectified signal from the bridge rectifier, the fourth current limiting device coupled directly to the anode of the fourth set of LEDs and configured to provide a fourth limited current to the fourth set of LEDs during a fourth portion of the power cycle.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/324,904Filed 7 Jul 2014 · us provisional application
Priority: 29 Jan 2014
Published: US 2015/0216006 A130 Jul 2015
Granted: 23 Aug 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H05B 45/44
Details of LED load circuits: with an active control inside an LED matrix
Y02B 20/30
Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps: semiconductor lamps, e.g. solid state lamps [SSL] light…
H05B
Electric heating
Y02B
Energy-efficient buildings