US3710284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Harmonic filter
Assignee: ABB Norden Holding AB
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Filing: 1971-03-01
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Granted: 1973-01-09
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Expires: 1991-03-01
Abstract
Abstract A harmonic filter is connected between two conductors joining a harmonic source to a network. The filter is composed of two impedance devices each including at least one impedance element, the impedance elements being either beoth inductive or both capacitative. One of the impedance devices is connected as a series element in one of the conductors, while the other impedance device is connected to the other of the conductors and an output of the first impedance device. There is a blocking circuit for the current of the network which forms a part of the second impedance device.
Inventors
- 👤 E Uhlmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:24
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/17; H03H7/1741; H03H7/175; H03H7/06; H03H7/07; H03H7/1716; H03H7/1725; H03H7/1775; H03H7/1791
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
Harmonic filter comprising two conductors which join a current source to a network for delivering a certain basic current to said network; said filter suppressing harmonics or ripple in the current, said filter comprising first and second impedance means each comprising at least one impedance element, the resultant impedance of which may have inductive or capacitive character, the first impedance means being connected as a series element in one of said conductors and having an intermediate tapping, the second impedance means being connected between the second conductor and the intermediate tapping on the first impedance means, the resultant impedance of said two impedance means having the same character and the second impedance means including a blocking circuit for the basic current of the source, the parts of the first impedance means on opposite sides of said intermediate tapping being mutually inductively coupled.
Claim 2
Dependent Claim
142 words
Harmonic filter comprising two conductors which join a current source to a network for delivering a certain basic current to said network; said filter suppressing harmonics or ripple in the current, said filter comprising first and second impedance means each comprising at least one impedance element, the resultant impedance of which may have inductive or capacitive character, the first impedance means being connected as a series element in one of said conductors and having an intermediate tapping, the second impedance means being connected between the second conductor and the intermediate tapping on the first impedance means, the resultant impedance of said two impedance means having the same character and the second impedance means including a blocking circuit for the basic current of the source, the parts of the first impedance means on opposite sides of said intermediate tapping being mutually inductively coupled.
Claim 3
Dependent Claim
24 words
A filter according to claim 1 in which said blocking circuit comprises a parallel resonance circuit tuned to the basic frequency of the filter.
Claim 4
Dependent Claim
50 words
A filter according to claim 1, in which said first impedance means comprises an inductive current divider parallel connected with the impedance element of the first impedance means; said current divider being provided with an intermediate tapping, said second impedance means being connected between said tapping and said second conductor.
Claim 5
Dependent Claim
37 words
A filter according to claim 1, which is intended for a DC network, in which said blocking circuit of said second impedance means comprises a capacitance in series with an impedance element, said impedance element being inductive.
Claim 6
Dependent Claim
32 words
A filter according to claim 4, in which said series capacitance of said second impedance means is inserted between an inductive current divider and an impedance element in said first impedance means.
References Cited (Backward Citations)
US2660712A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |