Output ripple reduction for power converters
First Claim
1. A circuit to reduce output ripple in a direct current (DC) power converter, the DC power converter comprising first and second output nodes which provides DC power that includes an AC ripple having a ripple frequency (fRIPPLE) which is a multiple of an AC power source which provides power to the DC power converter, the circuit comprising:
- a transformer comprising;
a core;
a primary winding wrapped around at least a portion of the core a first number of times, the primary winding comprising a first primary terminal having a first polarity and a second primary terminal having a second polarity opposite the first polarity, the first primary terminal electrically coupled to the first output node of the DC power converter; and
a secondary winding wrapped around at least a portion of the core a second number of times, the secondary winding comprising a first secondary terminal having the first polarity and a second secondary terminal having the second polarity, the first secondary terminal electrically coupled to a first load terminal of a load; and
a first capacitor having a first capacitor terminal and a second capacitor terminal, the first capacitor terminal electrically coupled to the second primary terminal and the second secondary terminal of the transformer, and the second capacitor terminal electrically coupled to the second output node of the DC power converter.
1 Assignment
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Accused Products
Abstract
Systems and methods for reducing low frequency (e.g., 100 Hz, 120 Hz) output ripple of a power converter which receives input power from an AC power source (e.g., AC mains). An output ripple reduction circuit is provided which is electrically coupled between an output of a power converter and a load (e.g., one or more LEDs). The output ripple reduction circuit comprises a transformer having a first winding and a second winding each wrapped around a core. The first winding has a first terminal electrically coupled to an output of the power converter and a second terminal coupled to a capacitor to form a first LC circuit. The second winding has a first terminal electrically coupled to a load and a second terminal coupled to the capacitor to form a second LC circuit.
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Citations
33 Claims
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1. A circuit to reduce output ripple in a direct current (DC) power converter, the DC power converter comprising first and second output nodes which provides DC power that includes an AC ripple having a ripple frequency (fRIPPLE) which is a multiple of an AC power source which provides power to the DC power converter, the circuit comprising:
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a transformer comprising; a core; a primary winding wrapped around at least a portion of the core a first number of times, the primary winding comprising a first primary terminal having a first polarity and a second primary terminal having a second polarity opposite the first polarity, the first primary terminal electrically coupled to the first output node of the DC power converter; and a secondary winding wrapped around at least a portion of the core a second number of times, the secondary winding comprising a first secondary terminal having the first polarity and a second secondary terminal having the second polarity, the first secondary terminal electrically coupled to a first load terminal of a load; and a first capacitor having a first capacitor terminal and a second capacitor terminal, the first capacitor terminal electrically coupled to the second primary terminal and the second secondary terminal of the transformer, and the second capacitor terminal electrically coupled to the second output node of the DC power converter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A solid state lighting system, comprising:
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a rectifier circuit which receives an alternating current (AC) signal and generates a rectified signal, the AC signal alternates at a source frequency (fSOURCE); a DC/DC converter which receives the rectified signal at a first input node and generates a DC signal across a first output node and a second output node, the DC signal including an AC ripple component which has a ripple frequency (fRIPPLE) that is twice the source frequency (fSOURCE); a load comprising at least one solid state light source, the load including a first load terminal and a second load terminal; and a resonant circuit, comprising; a transformer comprising; a core; a primary winding wrapped around at least a portion of the core a first number of times, the primary winding comprising a first primary terminal having a first polarity and a second primary terminal having a second polarity opposite the first polarity, the first primary terminal electrically coupled to the first output node of the DC/DC converter; and a secondary winding wrapped around at least a portion of the core a second number of times, the secondary winding comprising a first secondary terminal having the first polarity and a second secondary terminal having the second polarity, the first secondary terminal electrically coupled to a first load terminal of the load; and a first capacitor having a first capacitor terminal and a second capacitor terminal, the first capacitor terminal electrically coupled to the second primary terminal and the second secondary terminal of the transformer, and the second capacitor terminal electrically coupled to the second output node of the DC/DC power converter. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A circuit to reduce output ripple in a direct current (DC) power converter, the DC power converter provides DC power that includes an AC ripple having a ripple frequency (fRIPPLE) which is a multiple of an AC power source which provides power to the power DC converter, the circuit comprising:
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a transformer comprising; a core; a primary winding wrapped around at least a portion of the core a first number of times, the primary winding comprising a first primary terminal and a second primary terminal, the first primary terminal electrically coupled to an output node of the DC power converter; and a secondary winding wrapped around at least a portion of the core a second number of times, the secondary winding comprising a first secondary terminal and a second secondary terminal, the first secondary terminal electrically coupled to a load; and a capacitor having a first capacitor terminal electrically coupled to the second primary terminal and the second secondary terminal of the transformer, wherein the second primary terminal and the second secondary terminal have a same polarity. - View Dependent Claims (29, 30, 31, 32, 33)
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Specification