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US4027225A Expired / Lapsed US ⏱️ 0.0 years remaining

DC convertor

Assignee: ABB Norden Holding AB
•
Filing: 1975-10-17
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Granted: 1977-05-31
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Expires: 1995-10-17
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Abstract

Abstract A convertor for supplying a load with direct voltage pulses of variable frequency includes input terminals for connection to a DC source and a main circuit, with a filter circuit connected between the input terminals and the main circuit. The filter circuit includes a capacitive parallel branch and a series inductor connected between one of the input terminals and the capacitive parallel branch. A resistor for reducing the Q-value of the filter circuit is connected in parallel with the series inductor. A second series inductor may be connected in series with the parallel connection of the first series inductor and the resistor. The first series inductor has an inductance which, at low current values, is larger than that of the second inductor.

Inventors

  • 👤 Sten Elvin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 16:23
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/14; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/125; H02M3/135

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 110 words
A DC convertor for supplying a load with direct voltage pulses with a variable frequency, said convertor having input terminals for connection to a DC supply network and comprising a main circuit and a filter circuit connected between said input terminals and said main circuit, said filter circuit comprising a capacitive parallel branch and a first series inductor connected between an input terminal and said capacitive parallel branch, a resistor for reduction of the Q-value of the filter circuit connected in parallel with said first series inductor; and said first series inductor being saturated at a value of the convertor load current which is lower than the rated load current.
Claim 2
Dependent Claim 110 words
A DC convertor for supplying a load with direct voltage pulses with a variable frequency, said convertor having input terminals for connection to a DC supply network and comprising a main circuit and a filter circuit connected between said input terminals and said main circuit, said filter circuit comprising a capacitive parallel branch and a first series inductor connected between an input terminal and said capacitive parallel branch, a resistor for reduction of the Q-value of the filter circuit connected in parallel with said first series inductor; and said first series inductor being saturated at a value of the convertor load current which is lower than the rated load current.
Claim 3
Dependent Claim 32 words
A DC convertor according to claim 1, said filter circuit comprising a second series inductor, which is connected in series with the parallel connection of said first series inductor and said resistor.
Claim 4
Dependent Claim 30 words
A DC convertor according to claim 2, said first series inductor having an inductance which is, at least at low current values, larger than the inductance of said second inductor.

References Cited (Backward Citations)

US2730667A Cited
US2710938A Cited
US3291960A Cited
US3308311A Cited
US3583089A Cited
US3710284A Cited
US3745440A Cited
US3758840A Cited
US3859542A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-05-30 1980-11-29 1981-05-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-05-30 1984-11-29 1985-05-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-05-30 1988-11-29 1989-05-31 $7700.00 Window Closed / Lapsed

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