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US3857084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery charging systems
Assignee: Lucas Electrical Co Ltd
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Filing: 1973-07-25
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Granted: 1974-12-24
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Expires: 1993-07-25
Abstract
Abstract A battery charging system has a wound field alternator charging a battery and a voltage regulator for controlling the output of the alternator by controlling conduction of a thyristor in series with the field winding of the alternator. The thyristor requires to be turned off periodically, and this is achieved by mechanical means, preferably in the form of a pair of interrupted slip rings feeding the field winding.
Inventors
- 👤 M Allport
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:44
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: 8
Claim 1
Independent Claim
97 words
A battery charging system including a wound-field alternator charging a battery, and a voltage regulator for controlling the output of the alternator, the voltage regulator including a thyristor in series with the field winding of the alternator, means for providing gate current to the thyristor when the battery voltage is below a predetermined value, and thE system further including a pair of slip rings providing the required electrical connection to the field winding, one of said slip rings being interrupted so that the anode-cathode path of the thyristor is interrupted from time-to-time to turn the thyristor off.
Claim 2
Dependent Claim
97 words
A battery charging system including a wound-field alternator charging a battery, and a voltage regulator for controlling the output of the alternator, the voltage regulator including a thyristor in series with the field winding of the alternator, means for providing gate current to the thyristor when the battery voltage is below a predetermined value, and thE system further including a pair of slip rings providing the required electrical connection to the field winding, one of said slip rings being interrupted so that the anode-cathode path of the thyristor is interrupted from time-to-time to turn the thyristor off.
Claim 3
Dependent Claim
27 words
A system as claimed in claim 1 in which the rotating field winding is bridged by a re-circulating diode which minimises arcing at the interrupted slip ring.
Claim 4
Dependent Claim
71 words
A system as claimed in claim 1 in which the alternator charges the battery through a full wave rectifier, and also provides power through additional diodes to a third supply line connected to the battery through a warning lamp and a manually operable switch in series, the series circuit of the field winding and thyristor being connected across the battery in series with the warning lamp and the manually operable switch.
Claim 5
Dependent Claim
49 words
A system as claimed in claim 3 in which the series circuit of the field winding and thyristor is bridged by a resistor which provides a path to illuminate the warning lamp when the manually operable switch is closed but the slip rings stop with the thyristor circuit interrupted.
Claim 6
Dependent Claim
42 words
A system as claimed in claim 3 in which a resistor is connected across the anode-cathode of the thyristor so that initial excitation can be applied to the field winding when the manually operable switch is closed but the thyristor is off.
Claim 7
Dependent Claim
38 words
A wound-field alternator for use in a system as specified in claim 1, said alternator being characterised in that the ends of the field winding are connected to a pair of slip rings, one of which is interrupted.
Claim 8
Dependent Claim
18 words
An alternator as claimed in claim 6 having a diode connected between the ends of the field winding.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |