AC/DC conversion with reduced supply waveform distortion

Claim 1

An AC/DC converter for providing a regulated DC signal from an AC signal, comprising: first filter means for filtering a harmonic frequency fed back to the AC signal; rectifier means connected to said first filter means for rectifying the AC signal to provide a DC signal across two terminals of said rectifier means; a plurality of flyback circuits, each having a first winding connected in series with switching means for enabling and disabling current flow which are connected in parallel to said rectifier means, each of said plurality of flyback circuits further having a second winding which is inductively related to said first winding, said second winding from each of said plurality of flyback circuits being connected in parallel through an ORing diode at an output of the AC/DC converter; controller means for repeatedly and sequentially enabling and disabling said switching means in each of said plurality of flyback circuits such that said first winding in each of said plurality of flyback circuits is energized by said DC signal when said series switching means is enabled and said second winding in each of said plurality of flyback circuits is energized by said inductively related first winding when said series switching means is disabled so as to provide the regulated DC signal at said output of the AC/DC converter; and the cutoff frequency of the first filter means is MNf, where f equals the frequency of the AC signal, M equals the number of flyback circuits and N equals the number of times per period of the AC signal that said switching means are enabled and disabled.

Claim 14

A method of performing AC/DC conversion to provide an regulated DC signal from an AC signal comprising the steps of: filtering the AC signal with a first filter to reduce harmonic frequencies fed back to the AC signal rectifying the AC signal with a rectifier circuit to provide a DC signal across two terminals of said rectifier circuit; repeatedly and sequentially enabling and disabling a switch in each of a plurality of flyback circuits, each of said plurality of flyback circuits having a first winding connected in series with said switch which is connected in parallel across said terminals of said rectifier circuit and a second winding which is inductively related to said first winding, said second winding from each of said plurality of flyback circuits being connected in parallel at an output, such that said first winding in each of said plurality of flyback circuits is energized by said DC signal when said switch is enabled and said second winding in each of said plurality of flyback circuits is energized by said inductively related first winding when said switch is disabled so as to provide the regulated DC signal at said output; and the cutoff frequency of said first filter is MNf, where f equals the frequency of the AC signal, M equals the number of flyback circuits and N equal the number of times per period of the AC signal that said switching means are enabled and disabled.

Claim 15

A method of performing AC/DC conversion to provide an regulated DC signal from an AC signal comprising the steps of: filtering the AC signal with a first filter to reduce harmonic frequencies fed back to the AC signal rectifying the AC signal with a rectifier circuit to provide a DC signal across two terminals of said rectifier circuit; repeatedly and sequentially enabling and disabling a switch in each of a plurality of flyback circuits, each of said plurality of flyback circuits having a first winding connected in series with said switch which is connected in parallel across said terminals of said rectifier circuit and a second winding which is inductively related to said first winding, said second winding from each of said plurality of flyback circuits being connected in parallel at an output, such that said first winding in each of said plurality of flyback circuits is energized by said DC signal when said switch is enabled and said second winding in each of said plurality of flyback circuits is energized by said inductively related first winding when said switch is disabled so as to provide the regulated DC signal at said output; and the cutoff frequency of said first filter is MNf, where f equals the frequency of the AC signal, M equals the number of flyback circuits and N equal the number of times per period of the AC signal that said switching means are enabled and disabled.