US3963973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonsaturating asymmetric dc/dc converter
Assignee: Digital Equipment Corp
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Filing: 1974-06-26
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Granted: 1976-06-15
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Expires: 1994-06-26
Abstract
Abstract A DC converter including a transistor switch and a transformer having first and second windings connected so that the transistor passes asymmetrical current pulses to the first winding. When the switch opens, asymmetrical current pulses again pass through the first winding and through a gating circuit connected thereto. The instantaneous voltage across the second winding is used as the drive voltage for the transistor switch to prevent transformer saturation.
Inventors
- 👤 Johannes Volkert Vermolen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:43
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/40; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33538; H02M3/337; H02M3/3372
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
224 words
A direct current converter, comprising a series connection of a first direct current input terminal, current interrupting means active in one direction, a first transformer winding connected to a gating circuit, and a second direct current input terminal, a second series connection of a first direct current output terminal, a rectifying element, a second transformer winding electromagnetically coupled to the first transformer winding, and a second direct current output terminal, means connecting the said second series connection to a smoothing circuit elememt, closure of the current interrupting means enabling first asymmetrical current pulses to be passed through the first transformer winding thereby blocking the gating circuit, the said pulses inducing at the same time second asymmetrical current pulses in the second transformer winding, opening of the current interrupting means inducing third asymmetrical current pulses in the first transformer winding which are oppositely directed from the first asymmetrical current pulses to open the gating circuit, means including an electric energy storage member connecting the direct current input terminals, the current interrupting means including a current interrupting member in each of the connection leads to the first transformer winding, the gating circuit comprising two branches which are cross-wise connected between connection leads from the first transformer winding to the current interrupting members and from the current interrupting members to the two direct current input terminals, respectively.
Claim 2
Dependent Claim
224 words
A direct current converter, comprising a series connection of a first direct current input terminal, current interrupting means active in one direction, a first transformer winding connected to a gating circuit, and a second direct current input terminal, a second series connection of a first direct current output terminal, a rectifying element, a second transformer winding electromagnetically coupled to the first transformer winding, and a second direct current output terminal, means connecting the said second series connection to a smoothing circuit elememt, closure of the current interrupting means enabling first asymmetrical current pulses to be passed through the first transformer winding thereby blocking the gating circuit, the said pulses inducing at the same time second asymmetrical current pulses in the second transformer winding, opening of the current interrupting means inducing third asymmetrical current pulses in the first transformer winding which are oppositely directed from the first asymmetrical current pulses to open the gating circuit, means including an electric energy storage member connecting the direct current input terminals, the current interrupting means including a current interrupting member in each of the connection leads to the first transformer winding, the gating circuit comprising two branches which are cross-wise connected between connection leads from the first transformer winding to the current interrupting members and from the current interrupting members to the two direct current input terminals, respectively.
Claim 3
Dependent Claim
17 words
A direct current converter as claimed in claim 1 wherein the energy storage member comprises a capacitor.
Claim 4
Dependent Claim
222 words
A direct current converter comprising a first series connection including a first direct current input terminal, current interrupter active in one direction, a first transformer winding, and a second direct current input terminal, a gating circuit connected to the first transformer winding, a second series connection including a first direct current output terminal, a rectifying element, a second transformer winding electromagnetically coupled to the first transformer winding, and a second direct current output terminal, means connecting the said second series connection to a smoothing circuit element, means for applying a closure command signal to the current interrupter to allow the passage of first asymmetrical current pulses through the first transformer winding thereby blocking the gating circuit, the first and second transformer windings being relatively wound and the rectifying element being polarized so that said first current pulses induce at the same time second asymmetrical current pulses in the second transformer winding, opening of the current interrupter inducing third asymmetrical current pulses in the first transformer winding which are oppositely directed from the first asymmetrical current pulses to open the gating circuit, means directly connecting a signal element to terminals of the second transformer winding for generating, under the instantaneous control of a voltage difference between said terminals, a blocking signal for blocking the passage of said command signal to said current interrupter.
Claim 5
Dependent Claim
222 words
A direct current converter comprising a first series connection including a first direct current input terminal, current interrupter active in one direction, a first transformer winding, and a second direct current input terminal, a gating circuit connected to the first transformer winding, a second series connection including a first direct current output terminal, a rectifying element, a second transformer winding electromagnetically coupled to the first transformer winding, and a second direct current output terminal, means connecting the said second series connection to a smoothing circuit element, means for applying a closure command signal to the current interrupter to allow the passage of first asymmetrical current pulses through the first transformer winding thereby blocking the gating circuit, the first and second transformer windings being relatively wound and the rectifying element being polarized so that said first current pulses induce at the same time second asymmetrical current pulses in the second transformer winding, opening of the current interrupter inducing third asymmetrical current pulses in the first transformer winding which are oppositely directed from the first asymmetrical current pulses to open the gating circuit, means directly connecting a signal element to terminals of the second transformer winding for generating, under the instantaneous control of a voltage difference between said terminals, a blocking signal for blocking the passage of said command signal to said current interrupter.
Claim 6
Dependent Claim
67 words
A direct current converter as claimed in claim 1 further comprising a series resistor connected in a supply lead to one of the direct current input terminals, a switching element bridging said series resistor, a third transformer winding electromagnetically coupled to the first transformer winding, and a rectifying-smoothing circuit connected to said third winding for applying a control signal to the switching element to render same conductive.
Claim 7
Dependent Claim
191 words
A direct current converter comprising, a pair of input terminals for connection to a source of DC current, unidirectional controlled switching means, a transformer having first and second magnetically coupled windings, a gating circuit coupled to the first winding, means connecting said controlled switching means and said first winding in series across the input terminals, a pair of DC output terminals, a rectifying element, means connecting the second winding and the rectifying element in series across the DC output terminals, a filter element coupled to said DC output terminals, means for operating said switching means between its conductive and cut-off regions whereby first and second opposed asymmetric currents flow simultaneously through said first and second windings in the conductive condition of the switching means a third oppositely polarized asymmetric current flows in the first winding in the cut-off condition of the switching means, said first and third asymmetric currents being polarized to open and close the gating circuit, respectively, and means responsive to the instantaneous value of the voltage induced in the second winding for supplying a rapidly varying control signal to the operating means to control the operating time thereof.
Claim 8
Dependent Claim
191 words
A direct current converter comprising, a pair of input terminals for connection to a source of DC current, unidirectional controlled switching means, a transformer having first and second magnetically coupled windings, a gating circuit coupled to the first winding, means connecting said controlled switching means and said first winding in series across the input terminals, a pair of DC output terminals, a rectifying element, means connecting the second winding and the rectifying element in series across the DC output terminals, a filter element coupled to said DC output terminals, means for operating said switching means between its conductive and cut-off regions whereby first and second opposed asymmetric currents flow simultaneously through said first and second windings in the conductive condition of the switching means a third oppositely polarized asymmetric current flows in the first winding in the cut-off condition of the switching means, said first and third asymmetric currents being polarized to open and close the gating circuit, respectively, and means responsive to the instantaneous value of the voltage induced in the second winding for supplying a rapidly varying control signal to the operating means to control the operating time thereof.
Claim 9
Dependent Claim
75 words
A direct current converter as claimed in claim 5 further comprising a capacitor connected across the DC input terminals and wherein the switching means includes first and second controlled electronic switches in series with the first winding, and said gating circuit comprises first and second unidirectional current elements connected cross-wire between the terminals of the first winding and the terminals of said first and second switches that are electrically closest to the DC input terminals.
Claim 10
Dependent Claim
49 words
A direct current converter as claimed in claim 5 wherein said gating circuit includes a rectifying element and a voltage threshold element serially connected to the first winding and wherein the control signal supplying means is coupled to the second winding at the input side of the filter element.
Claim 11
Dependent Claim
58 words
A direct current converter as claimed in claim 5 wherein said control signal supplying means includes a transistor with its control electrode coupled to the second winding at the input side of the filter element and an output electrode coupled to an inhibit circuit connected between the operating means and a control electrode of the controlled switching means.
Claim 12
Dependent Claim
47 words
A direct current converter as claimed in claim 5 further comprising a capacitor connected across the DC input terminals and wherein said gating circuit includes diode means coupling the first winding to the capacitor and poled so that the capacitor is recharged by the third asymmetric current.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |