US3596369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transformerless power supply with line to load isolation
Assignee: International Business Machines Corp
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Filing: 1969-12-22
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Granted: 1971-08-03
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Expires: 1989-12-22
Abstract
Abstract A transformerless power supply is disclosed in which a source capacitor has its charge maintained at a fraction of the AC supply voltage and a plurality of sink capacitors are sequentially switched between a charging connection to the source capacitor and a discharging connection to a load circuit. The load circuit is isolated from the line at all times to maintain safety protection. The use of a comparatively high switching speed will reduce the filter requirements in the load circuit and this together with the elimination of the transformer results in very substantial size and weight reductions from conventional supplies. Voltage regulation at the load is achieved by controlling the voltage to which the sink capacitors are charged from the source capacitor.
Inventors
- 👤 Jack A Dickerson
- 👤 Gerald H Ottaway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:51
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/02; H02M7/04; H02M7/12; H02M7/145; H02M7/155; H02M3/00; H02M3/02; H02M3/04; H02M3/06; H02M3/07
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
141 words
A direct current power supply comprising a source capacitor, a phase-controlled rectifier for charging said source capacitor to a predetermined voltage from an AC power source having an RMS voltage substantially higher than said predetermined voltage, a plurality of sink capacitors, a first switch means for each sink capacitor to connect said sink capacitor across said source capacitor, a second switch means for each sink capacitor to connect said sink capacitor to a load circuit, and a sequencing switch to alternately operate said first and second switch means to enable each sink capacitor to transfer a charge from said source capacitor to said load circuit, said sequencing switch controlling said first switch means for said plurality of switch capacitors to operate in a fixed sequence and controlling said second switch means to operate in the same sequence with a time displacement.
Claim 2
Dependent Claim
141 words
A direct current power supply comprising a source capacitor, a phase-controlled rectifier for charging said source capacitor to a predetermined voltage from an AC power source having an RMS voltage substantially higher than said predetermined voltage, a plurality of sink capacitors, a first switch means for each sink capacitor to connect said sink capacitor across said source capacitor, a second switch means for each sink capacitor to connect said sink capacitor to a load circuit, and a sequencing switch to alternately operate said first and second switch means to enable each sink capacitor to transfer a charge from said source capacitor to said load circuit, said sequencing switch controlling said first switch means for said plurality of switch capacitors to operate in a fixed sequence and controlling said second switch means to operate in the same sequence with a time displacement.
Claim 3
Dependent Claim
61 words
A power supply as set out in claim 1 including a load voltage-regulating control, said control comprising for each sink capacitor, a comparing circuit to provide a signal voltage when the voltage of its sink capacitor is greater than a reference voltage and a switch control circuit to prevent operation of said first switch means when said signal voltage is present.
Claim 4
Dependent Claim
44 words
The power supply set out in claim 1 including an output voltage-regulating circuit responsive to the output voltage of said power supply to prevent closure of any of said first switch means so long as said output voltage is greater than a predetermined voltage.
Claim 5
Dependent Claim
76 words
The power supply set forth in claim 1 including an output voltage-regulating circuit comprising a voltage comparator to provide a signal voltage when the voltage applied to its input circuit is above a reference level, a control means for said first switch means to open any of said first switch means when said signal voltage is present, and a circuit connecting one of said sink capacitors at a time to the input circuit of said comparator.
Claim 6
Dependent Claim
166 words
A direct current power supply comprising a source capacitor, an AC power input, a controlled-phase rectifier between said power input and said source capacitor, a phase control network for said rectifier to charge said source capacitor to a voltage substantially lower than the RMS voltage of said AC power input, a plurality of first switches connected to said source capacitor, a sequencing switch to sequentially close and sequentially open said plurality of first switches, a sink capacitor for each first switch, each said sink capacitor being connected for charging to said source capacitor by its said first switch, a load circuit, a plurality of second switches, each to connect one of said sink capacitors to supply power to said load circuit, connections from said second Switches to said sequencing switch to open and close said second switches in the same sequence as said first switches but with a predetermined time delay and output voltage-regulating means to additionally control the closing and opening of said first switches.
Claim 7
Dependent Claim
166 words
A direct current power supply comprising a source capacitor, an AC power input, a controlled-phase rectifier between said power input and said source capacitor, a phase control network for said rectifier to charge said source capacitor to a voltage substantially lower than the RMS voltage of said AC power input, a plurality of first switches connected to said source capacitor, a sequencing switch to sequentially close and sequentially open said plurality of first switches, a sink capacitor for each first switch, each said sink capacitor being connected for charging to said source capacitor by its said first switch, a load circuit, a plurality of second switches, each to connect one of said sink capacitors to supply power to said load circuit, connections from said second Switches to said sequencing switch to open and close said second switches in the same sequence as said first switches but with a predetermined time delay and output voltage-regulating means to additionally control the closing and opening of said first switches.
Claim 8
Dependent Claim
52 words
A power supply as set out in claim 5 wherein said voltage-regulating means comprises a voltage comparator for each sink capacitor and a first switch control means to prevent connection of its associated sink capacitor to said source capacitor so long as the voltage of said sink capacitor exceeds a predetermined level.
Claim 9
Dependent Claim
120 words
A low voltage power supply comprising a source capacitor, an AC power input, a phase-controlled rectifier to connect said AC input to said source capacitor during the decreasing voltage part of the cycle of said AC power to charge said source capacitor to a relatively small part of the RMS voltage of said power input, a plurality of sink capacitors, first sequentially operated switches to connect said sink capacitors to said source capacitor seriatim, a second set of switches operated in the same sequence as said sequentially operated switches but having a predetermined time delay therefrom to connect said sink switches to an output load circuit, and output voltage control means to control opening of said first sequentially operated switches.
Claim 10
Dependent Claim
120 words
A low voltage power supply comprising a source capacitor, an AC power input, a phase-controlled rectifier to connect said AC input to said source capacitor during the decreasing voltage part of the cycle of said AC power to charge said source capacitor to a relatively small part of the RMS voltage of said power input, a plurality of sink capacitors, first sequentially operated switches to connect said sink capacitors to said source capacitor seriatim, a second set of switches operated in the same sequence as said sequentially operated switches but having a predetermined time delay therefrom to connect said sink switches to an output load circuit, and output voltage control means to control opening of said first sequentially operated switches.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |