Patent US3721888A successfully refreshed from Google Patents.
US3721888A
Expired / Lapsed
US
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Battery charging systems for road vehicles
Assignee: ZF International UK Ltd
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Filing: 1971-07-27
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Granted: 1973-03-20
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Expires: 1991-07-27
Abstract
Abstract A battery charging system for a road vehicle has a three-phase wound field alternator for charging the vehicle battery. There are three thyristors with their cathodes connected to the phase points of the alternator and their anodes connected to the positive battery terminals through the field winding of the alternator, an means sensitive to the battery voltage for providing gate current to the thyristors only when the battery voltage is below a predetermined value.
Inventors
- 👤 M Allport
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:59
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/14; H02J7/16; H02J7/24; H02J7/2437; Y; Y02; Y02T; Y02T10/00; Y02T10/80; Y02T10/92
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
71 words
A battery charging system for a road vehicle including a three phase wound field alternator charging the vehicle battery, three thyristors having their cathodes connected to the phase points of the alternator, their anodes connected to the positive battery terminal through the field winding of the alternator, and means sensitive to the battery voltage for providing gate current to the thyristors only when the battery voltage is below a predetermined value.
Claim 2
Dependent Claim
71 words
A battery charging system for a road vehicle including a three phase wound field alternator charging the vehicle battery, three thyristors having their cathodes connected to the phase points of the alternator, their anodes connected to the positive battery terminal through the field winding of the alternator, and means sensitive to the battery voltage for providing gate current to the thyristors only when the battery voltage is below a predetermined value.
Claim 3
Dependent Claim
49 words
A system as claimed in claim 1 in which the gate of each thyristor is connected through a resistor to the same phase point as the cathode of the thyristor, so that the gates are reverse biased by the alternator when the battery voltage is above the predetermined value.
Claim 4
Dependent Claim
18 words
A system as claimed in claim 1 including a resistive path for energizing the field winding on starting.
References Cited (Backward Citations)
US3364416A
Cited
US3539907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |