Patent US3634733A successfully refreshed from Google Patents.
US3634733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit for inductive loads
Assignee: Alcatel CIT SA
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Filing: 1970-11-30
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Granted: 1972-01-11
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Expires: 1990-11-30
Abstract
Abstract For energizing an inductive load with a maximum current of brief duration followed by a steady current, less than the maximum, the inductive load is initially connected, by means of an amplifier switch, across a voltage source of relatively high-output voltage and subsequently connected, by means of another amplifier switch, across a voltage source of relatively low-output voltage. Trigger circuitry is operable to apply an input pulse of predetermined duration to the amplifier switch associated with the voltage source of high-output voltage and simultaneously trigger a delay circuit arranged to apply an input voltage to the amplifier switch associated with the source of low voltage. Respective diodes connect a common point the outputs of the respective amplifier switches, the common point and a point at a reference potential provide respective first and second connections to the inductive load.
Inventors
- 👤 Marcel-Louis Boyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:14
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/04113; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/18; H01F7/1805
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
Circuitry for controlling an elecTrical current in an inductive load, comprising: first and second unidirectional voltage sources providing respective relatively low and relatively high output voltages; a first switching element connected to said first voltage source and a point at a reference potential; a second switching element connected to said second voltage source and the point at the reference potential; said first and second switching elements each having an input and an output; trigger circuitry operable to apply an input pulse of predetermined duration to said second switching element and to simultaneously trigger a delay circuit arranged to apply an input voltage to said first switching element after a delay substantially equal to the input pulse duration; and respective diodes connecting a common point to the outputs of said first and second switching elements, the common point and the point at the reference potential providing respective first and second connections to the inductive load.
Claim 2
Dependent Claim
154 words
Circuitry for controlling an elecTrical current in an inductive load, comprising: first and second unidirectional voltage sources providing respective relatively low and relatively high output voltages; a first switching element connected to said first voltage source and a point at a reference potential; a second switching element connected to said second voltage source and the point at the reference potential; said first and second switching elements each having an input and an output; trigger circuitry operable to apply an input pulse of predetermined duration to said second switching element and to simultaneously trigger a delay circuit arranged to apply an input voltage to said first switching element after a delay substantially equal to the input pulse duration; and respective diodes connecting a common point to the outputs of said first and second switching elements, the common point and the point at the reference potential providing respective first and second connections to the inductive load.
Claim 3
Dependent Claim
15 words
Circuitry as claimed in claim 1, wherein said first and second switching elements are identical.
Claim 4
Dependent Claim
17 words
Circuitry as claimed in claim 1, wherein each switching element comprises a pair of NPN-transistors in cascade.
Claim 5
Dependent Claim
29 words
Circuitry as claimed in claim 1, including connection means for effecting connection of said inductive load to said first voltage source independently of said first hand second switching elements.
Claim 6
Dependent Claim
49 words
Circuitry as claimed in claim 1, wherein said delay circuit includes a capacitance charged through a resistance by said trigger circuitry, the time constant of the charging circuit being so chosen that the voltage across the capacitance reaches a predetermined value after a period equal to the required delay.
Claim 7
Dependent Claim
20 words
Circuitry as claimed in claim 1, wherein said first and second switching elements are amplifiers normally biased to be nonconductive.
Claim 8
Dependent Claim
54 words
Circuitry as claimed in claim 6, wherein said trigger circuitry includes a monostable multivibrator selectively actuatable to apply said input pulse of predetermined duration to said second switching element to render that amplifier conductive and to said delay circuit to render said first switching element conductive after a period equal to said predetermined duration.
Claim 9
Dependent Claim
29 words
Circuitry as claimed in claim 7, including connection means for effecting connection of said inductive load to said first voltage source independently of said first and second switching elements.
Claim 10
Dependent Claim
27 words
Circuitry as claimed in claim 8, wherein said connection means includes a resistance connected between the output of said first switching element and said first voltage source.
Claim 11
Dependent Claim
49 words
Circuit as claimed in claim 7, wherein said delay circuit includes a capacitance charged through a resistance by said trigger circuitry, the time constant of the charging circuit being so chosen that the voltage across the capacitance reaches a predetermined value after a period equal to the required delay.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |