Low distortion alternating current output active power factor correction circuit using two bi-directional switching regulations
AssigneeAlliedSignal Inc.
InventorPhilip M. Cowett, Jr.
Life of this patent
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Abstract
A circuit wherein a current sensing device is incorporated in an AC input line. An AC output is taken from the output of said current sensing device and from an other AC input line. Circuitry including two bi-directional switching regulators (positive and negative) and two energy storage capacitors adds current to or subtracts current from the instantaneous output load current. The arrangement is such that the AC output is equal to the AC input with no regulation effect. Substantially one hundred percent efficiency results when very little power factor correction is required.
Claims10
A low distortion alternating current output active power factor correction circuit, comprising:
- a pair of alternating current input lines;
- switching means connected to one of the pair of alternating current input lines;
- bi-directional switching regulator means connected to the switching means and operative in one polarity and in an opposite polarity;
- a current sensor connected to the other of the pair of alternating current input lines, with said current sensor providing an output at an output conductor;
- control means connected to the one of the pair of input lines, the current sensor output conductor and the switching means and effective for controlling the switching means to render the bi-directional switching regulator inactive in one of the one and the opposite polarities;
- the bi-directional switching regulator means connected to an output conductor in the one polarity, to an output conductor in the opposite polarity and to a common output conductor;
- a first bulk energy storage capacitor connected across the output conductor in one polarity and the common output conductor, with a direct current output being provided across said first capacitor;
- a second bulk energy storage capacitor connected across the output conductor in the opposite polarity and the common output conductor, with a direct current output being provided across said second capacitor;
- and
- a power factor corrected alternating current output being provided across the one alternating current input line and the output conductor of the current sensor for being connected to an alternating current load.
Dependencies are inferred from the claim text.