US3602739A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital magnetic recording circuit bidirectional load switching having higher load voltage at time of reversal
Assignee: Westinghouse Electric Corp
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Filing: 1969-04-16
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Granted: 1971-08-31
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Expires: 1989-04-16
Abstract
Abstract A circuit is disclosed for reversing the current through an inductive element, such as a coil of a magnetic recording head used for digital recording, wherein two pairs of translating devices, such as transistors, are utilized with the inductive element being connected between a first device of each pair so that current flows from a first operating voltage source in opposite directions through the inductive element depending upon which device is conductive. The second device of the respective pairs is turned on when the current through the inductive element is to be reversed so as to connect a second operating voltage source to the inductive element and cause the rapid reversal of current therethrough.
Inventors
- 👤 Tamas I Pattantyus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:54
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K17/66; H03K17/661; H03K17/662; H03K17/04; H03K17/041; H03K17/04113
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
240 words
In a circuit for reversing the current through an inductive element operative with first and second voltage sources, the combination of: first and second translating devices operatively connected between said first source and a reference potential; said inductive element being operatively connected between said first and second devices; first means for turning on one of said first and second devices when turning off the other so that current is supplied to said inductive element in one direction when said first device is conductive and in the other direction when said second device is conductive; third and fourth translating devices operatively connected between said first and second devices, respectively, and said second source; second means for turning on said third or fourth device when said first or second device, respectively, is turned on to operatively connect said second source therethrough to said inductive element so that the current through said inductive element is rapidly reversed and for turning off the conductive of said third or fourth device when the reversed current reaches a predetermined magnitude; and first and second unidirectional devices operatively connected, respectively, between said first and second translating devices and said reference potential so that said first or second unidirectional device provides a conductive path to said reference potential therethrough when said first or second translating device, respectively, is conductive and blocks a conductive path to said reference potential when said third or fourth translating device, respectively, is conductive.
Claim 2
Dependent Claim
240 words
In a circuit for reversing the current through an inductive element operative with first and second voltage sources, the combination of: first and second translating devices operatively connected between said first source and a reference potential; said inductive element being operatively connected between said first and second devices; first means for turning on one of said first and second devices when turning off the other so that current is supplied to said inductive element in one direction when said first device is conductive and in the other direction when said second device is conductive; third and fourth translating devices operatively connected between said first and second devices, respectively, and said second source; second means for turning on said third or fourth device when said first or second device, respectively, is turned on to operatively connect said second source therethrough to said inductive element so that the current through said inductive element is rapidly reversed and for turning off the conductive of said third or fourth device when the reversed current reaches a predetermined magnitude; and first and second unidirectional devices operatively connected, respectively, between said first and second translating devices and said reference potential so that said first or second unidirectional device provides a conductive path to said reference potential therethrough when said first or second translating device, respectively, is conductive and blocks a conductive path to said reference potential when said third or fourth translating device, respectively, is conductive.
Claim 3
Dependent Claim
17 words
The combination of claim 1 wherein: said first, second, third and fourth translating devices comprise transistor devices.
Claim 4
Dependent Claim
134 words
The combination of claim 2 wherein: each of said transistor devices includes input and output electrodes, said inductive element being operatively connected between a First output electrode of said first and second devices, said first means including first and second input means operatively connected to said input electrode of said first and second devices, respectively, said second means including third and fourth input means operatively connected to said input electrodes of said third and fourth devices, respectively, a second output electrode of said first and second devices operatively connected to a first output electrode of said third and fourth devices, respectively, said first output electrode of said first and second devices operatively connected to said first voltage source, said second output electrode of said third and fourth devices, respectively, connected to said second source.
Claim 5
Dependent Claim
16 words
The combination of claim 1 wherein: said inductive element is adapted for use in digital recording.
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) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |