Patent US3646402A successfully refreshed from Google Patents.
US3646402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching of inductances
Assignee: AT&T Inc
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Filing: 1970-08-20
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Granted: 1972-02-29
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Expires: 1990-08-20
Abstract
Abstract Electric current can be rapidly switched from one inductance to another similar inductance if a capacitor is connected in parallel with the two inductances and diodes are suitably placed. The required power supply need only be large enough to maintain the steady state current flow. Switching takes place when the voltage applied to the circuit is reversed. An exemplary current reversing scheme uses a combination of a high voltage silicon controlled rectifier and a lower voltage switching transistor.
Inventors
- 👤 Joseph Henry Condon
- 👤 David William Hagelbarger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:28
CPC Classifications
H; H01; H01F; H01F6/00; H01F6/005; H01F29/00; H01F29/14; H01F29/143; H01F7/00; H01F7/06; H01F7/08; H01F7/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
118 words
A circuit including means for switching electric current from a first portion to a parallel connected second portion characterized in that the said first portion is similar in inductance to the said second portion and in that the said first portion comprises a series connected first unidirectional device and the said second portion comprises a series connected second unidirectional device opposite in polarity to the said first unidirectional device and in that the said circuit comprises a capacitor connected in parallel with the said first and second portions with the result that the said switching is rapidly accomplished when the polarity of the voltage applied to the said first and second portion by the said means is reversed.
Claim 2
Dependent Claim
118 words
A circuit including means for switching electric current from a first portion to a parallel connected second portion characterized in that the said first portion is similar in inductance to the said second portion and in that the said first portion comprises a series connected first unidirectional device and the said second portion comprises a series connected second unidirectional device opposite in polarity to the said first unidirectional device and in that the said circuit comprises a capacitor connected in parallel with the said first and second portions with the result that the said switching is rapidly accomplished when the polarity of the voltage applied to the said first and second portion by the said means is reversed.
Claim 3
Dependent Claim
16 words
A circuit of claim 1 in which the said first portion comprises at least one branch.
Claim 4
Dependent Claim
16 words
A circuit of claim 2 in which each said branch comprises at least one inductor device.
Claim 5
Dependent Claim
28 words
A circuit of claim 3 in which each branch comprises selection means for selecting the said at least one branch to be included in the said first portion.
Claim 6
Dependent Claim
23 words
A circuit of claim 4 in which the said first unidirectional device together with the said selection means comprise a controlled rectifier device.
Claim 7
Dependent Claim
18 words
A circuit of claim 1 in which the said first portion comprises the energizing coil of an electromagnet.
Claim 8
Dependent Claim
22 words
A circuit of claim 6 in which the said energizing coil is composed essentially of a material selected for its superconducting properties.
Claim 9
Dependent Claim
20 words
A circuit of claim 1 in which the said first portion comprises at least one winding of a stepping motor.
Claim 10
Dependent Claim
20 words
A circuit of claim 1 in which the said first portion comprises the control winding of a saturable reactor device.
Claim 11
Dependent Claim
15 words
A circuit of claim 1 in which the said means comprises a third unidirectional device.
Claim 12
Dependent Claim
38 words
A circuit of claim 10 in which the said means comprises a switching transistor in the common emitter configuration, the collector lead of which said transistOr is electrically connected to the cathode lead of a controlled rectifier device.
Claim 13
Dependent Claim
67 words
A circuit of claim 11 in which the said controlled rectifier device is a bidirectional controlled rectifier device and in which the said means includes the said third unidirectional device connected to the anode lead of the said controlled rectifier device and a fourth unidirectional device connected to the gate lead of the said controlled rectifier device in the same polarity as the said third unidirectional device.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |