US5790389A
Expired / Lapsed
US
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Consolidated soft-switching AC/DC converters
Assignee: VIRGINIA POWER TECHNOLOGIES Inc
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Filing: 1996-05-31
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Granted: 1998-08-04
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Expires: 2016-05-31
Abstract
Abstract A family of consolidated soft-switching AC/DC PFC converters, for power supplies and related uses. Any of several effective circuitry designs is interposed from an intermediate node on a rectified positive lead to a preselected intermediate node operative as a high-frequency AC source in a DC/DC conversion stage. Features so optimizable, individually or in combination, include power factor, regulation, and efficiency, plus reduction in circuit complexity.
Inventors
- 👤 Guichao Hua
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:21
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/42; H02M1/4208; H02M1/4258; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; Y; Y02; Y02B; Y02B70/00; Y02B70/10; Y02P; Y02P80/00; Y02P80/10
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
178 words
An AC/DC converter comprising AC/DC rectifier circuitry having a pair of AC input terminals, and DC/DC converter circuitry having a pair of DC output terminals, interconnected by a pair of respectively positive and negative (or neutral) leads each functioning as an output lead from the rectifier circuitry and as an input lead to the converter circuitry, which itself is subjected to only a single high-frequency power switch; wherein the positive lead as a rectifier output lead contains a filter inductor then as a converter input lead contains a diode, and a bridging positive-to-negative lead contains a smoothing filter capacitor and connects it from the converter input end of the positive lead to the negative lead; and intermediate circuitry including (a) an intermediate lead connected from between the filter inductor and the diode to a high-frequency AC voltage source in the DC/DC converter circuitry, and (b) a further inductor connected in series (i) from the junction of the positive and intermediate leads to the diode in the positive lead, or (ii) with a DC-blocking element in the intermediate lead.
Claim 2
Dependent Claim
178 words
An AC/DC converter comprising AC/DC rectifier circuitry having a pair of AC input terminals, and DC/DC converter circuitry having a pair of DC output terminals, interconnected by a pair of respectively positive and negative (or neutral) leads each functioning as an output lead from the rectifier circuitry and as an input lead to the converter circuitry, which itself is subjected to only a single high-frequency power switch; wherein the positive lead as a rectifier output lead contains a filter inductor then as a converter input lead contains a diode, and a bridging positive-to-negative lead contains a smoothing filter capacitor and connects it from the converter input end of the positive lead to the negative lead; and intermediate circuitry including (a) an intermediate lead connected from between the filter inductor and the diode to a high-frequency AC voltage source in the DC/DC converter circuitry, and (b) a further inductor connected in series (i) from the junction of the positive and intermediate leads to the diode in the positive lead, or (ii) with a DC-blocking element in the intermediate lead.
Claim 3
Dependent Claim
15 words
The AC/DC converter according to claim 1, wherein the DC-blocking circuit element comprises a capacitor.
Claim 4
Dependent Claim
16 words
The AC/DC converter according to claim 1, wherein the DC-blocking circuit element comprises a further diode.
Claim 5
Dependent Claim
25 words
The AC/DC converter according to claim 1, wherein the intermediate input lead to the converter circuitry connects to the power switch as such AC source.
Claim 6
Dependent Claim
26 words
The AC/DC converter according to claim 4, wherein the converter circuitry includes an isolation transformer with primary winding connected across the positive and intermediate input leads.
Claim 7
Dependent Claim
15 words
The AC/DC converter according to claim 5, wherein the converter circuitry is of flyback type.
Claim 8
Dependent Claim
15 words
The AC/DC converter according to claim 5, wherein the converter circuitry is of forward type.
Claim 9
Dependent Claim
38 words
The AC/DC converter according to claim 5, wherein the primary winding is tapped intermediate its ends, and the intermediate input lead to the converter circuitry connects to that intermediate tap of the primary winding as such AC source.
Claim 10
Dependent Claim
15 words
The AC/DC converter according to claim 8, wherein the converter circuitry is of flyback type.
Claim 11
Dependent Claim
15 words
The AC/DC converter according to claim 8, wherein the converter circuitry is of forward type.
Claim 12
Dependent Claim
36 words
AC/DC converter according to claim 10, wherein the transformer has, besides its primary winding a reverse-wound second winding in series connection from the negative lead through a diode to the positive lead as a reset winding.
Claim 13
Dependent Claim
138 words
In an AC/DC single stage converter having AC/DC rectifier circuitry connected to DC/DC converter circuitry by respective positive and negative (or neutral) leads functioning as rectifier output leads and also as converter input leads, the positive lead containing a filter inductor at the rectifier output followed in series by a diode toward the converter input, and having also a bridging lead connecting a smoothing filter capacitor across the positive and negative leads at the converter input; the improvement comprising an intermediate lead, connecting from a node on the positive lead intermediate the filter inductor and the diode to a node in the converter circuitry operative as a high-frequency AC source, and containing a further inductor followed by a DC-blocker selected with the further inductor to obtain acceptable power factor, r.m.s losses, output voltage regulation, or overall operating efficiency.
Claim 14
Dependent Claim
138 words
In an AC/DC single stage converter having AC/DC rectifier circuitry connected to DC/DC converter circuitry by respective positive and negative (or neutral) leads functioning as rectifier output leads and also as converter input leads, the positive lead containing a filter inductor at the rectifier output followed in series by a diode toward the converter input, and having also a bridging lead connecting a smoothing filter capacitor across the positive and negative leads at the converter input; the improvement comprising an intermediate lead, connecting from a node on the positive lead intermediate the filter inductor and the diode to a node in the converter circuitry operative as a high-frequency AC source, and containing a further inductor followed by a DC-blocker selected with the further inductor to obtain acceptable power factor, r.m.s losses, output voltage regulation, or overall operating efficiency.
Claim 15
Dependent Claim
61 words
Improvement in an AC/DC converter according to claim 12, wherein the intermediate lead connects in the converter circuitry to a junction of (i) the drain of a power switch having its source connected to the the negative input lead, and (ii) one end of a primary winding of an isolation transformer having its other end connected to the positive input lead.
Claim 16
Dependent Claim
64 words
Improvement in an AC/DC converter according to claim 12, wherein the converter circuitry includes an isolation transformer having a primary winding with one end connected to the positive input lead, and wherein the intermediate lead connects to the primary winding at a tap located a distance measurable in turns up to as much as about 85 percent of the length from its other end.
Claim 17
Dependent Claim
32 words
Improvement in an AC/DC converter according to claim 14, wherein the tap to which the intermediate lead connects is located at about one third of the primary winding from the other end.
Claim 18
Dependent Claim
24 words
AC/DC converter according to claim 12, wherein the converter circuitry is one of the following types: boost, buck, buck-boost, Cuk, flyback, forward, SEPIC, Zeta.
References Cited (Backward Citations)
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