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US 10,757,782 B2Granted
AC/DC converters having power factor correction
AssigneeSignify Holding B.V.
InventorsGeorg Sauerlander, Christian Hattrup
Life of this patent
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Abstract
An AC/DC converter and conversion method are provided, in which an AC input is rectified and shaped by a waveform shaping capacitor. A current source circuit is used to provide the output current to the output load which has a parallel bulk capacitor. The current source circuit is switched on and off with timing which is dependent on the phase of the AC input signal. This enables a relatively high power factor, for example between 0.7 and 0.9, with low cost circuitry with few components.
Claims15
An AC/DC converter, comprising:
- an AC input for receiving an AC input signal and a DC output for supplying power to a load;
- a rectifier providing a rectified signal between first and second rectifier terminals;
- a waveform shaping capacitor connected between the first and second rectifier terminals;
- a current source circuit connected in series with the DC output;
- and
- a bulk capacitor connected in parallel with the DC output having a larger capacitance than the waveform shaping capacitor,
- wherein the current source circuit is adapted to successively switch on and off during a switching period, the switching period being a period wherein a voltage across the waveform shaping capacitor is larger than an actual voltage across the load, and wherein when the current source circuit is switched on, the current is provided to the load and the parallel bulk capacitor, and when the current source circuit is switched off, no current is delivered to the load and the parallel bulk capacitor, but the bulk capacitor maintains a current through the load such that the requirements for IEC62000-3-2 are met.
4 more elements
An AC/DC conversion method, comprising:
- receiving an AC input signal;
- rectifying the AC input signal;
- shaping the rectified signal using a waveform shaping capacitor;
- and
- providing an output current to an output load with a bulk capacitor in parallel with the output load having a larger capacitance than the waveform shaping capacitor, the output current being delivered from the rectifier and waveform shaping capacitor using a current source circuit, wherein the method comprises switching on and off the current source circuit with timing which is dependent on the phase of the AC input signal such that the requirements for IEC62000-3-2 are met.
2 more elements
Dependencies are inferred from the claim text.