US4156836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery charging system for road vehicles
Assignee: ZF International UK Ltd
•
Filing: 1977-12-14
•
Granted: 1979-05-29
•
Expires: 1997-12-14
Abstract
Abstract A battery charging system includes a pair of alternators having rectified outputs which are connected in parallel. The field currents of the respective alternators are controlled by respective oscillatory switching circuits which are responsive to rectified output voltages from the respective alternators. Each respective switching circuit is coupled to an output voltage sensing circuit of the other alternator, so that oscillatory switching of one switching circuit causes oscillatory switching of the other switching circuit.
Inventors
- 👤 David Wiley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:27
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/14; H02J7/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
A battery charging system for a road vehicle comprising in combination a pair of alternators each having a rectifier and an associated field winding, a pair of voltage regulators controlling the field current of each alternator in accordance with the voltage at the output of the associated rectifier, each voltage regulator including a voltage sensing circuit connected across the rectifier output and an oscillatory switching circuit arranged to oscillate between conductive and non-conductive states when the voltage across the voltage sensing circuit exceeds a predetermined value, the field winding of the associated alternator being connected to be controlled by said switching circuit, and cross coupling means connecting the switching circuit of each voltage regulator to the voltage sensing circuit of the other regulator, so that oscillatory switching of one switching circuit causes oscillatory switching of the other switching circuit.
Claim 2
Dependent Claim
139 words
A battery charging system for a road vehicle comprising in combination a pair of alternators each having a rectifier and an associated field winding, a pair of voltage regulators controlling the field current of each alternator in accordance with the voltage at the output of the associated rectifier, each voltage regulator including a voltage sensing circuit connected across the rectifier output and an oscillatory switching circuit arranged to oscillate between conductive and non-conductive states when the voltage across the voltage sensing circuit exceeds a predetermined value, the field winding of the associated alternator being connected to be controlled by said switching circuit, and cross coupling means connecting the switching circuit of each voltage regulator to the voltage sensing circuit of the other regulator, so that oscillatory switching of one switching circuit causes oscillatory switching of the other switching circuit.
Claim 3
Dependent Claim
51 words
A battery charging system as claimed in claim 1 in which said voltage sensing means of each regulator includes in a resistor chain and an input transistor sensitive to the voltage at one point on the resistor chain, said cross-coupling means being connected to a different point on said resistor chain.
Claim 4
Dependent Claim
20 words
A battery charging system as claimed in claim 2, in which said cross coupling means comprises a pair of capacitors.
Claim 5
Dependent Claim
59 words
A battery charging system as claimed in claim 3, in which each regulator includes the series combination of a feedback resistor and a feedback capacitor connected between the switching circuit and the base of the input transistor, said feedback capacitor/resistor combination having a time constant longer than that of the cross-coupling capacitor with a resistor of the resistor chain.
Claim 6
Dependent Claim
44 words
A battery charging system as claimed in claim 4, in which the resistor chain is connected between an auxiliary output of the rectifier, isolated from the main battery charging output thereof, but at the same voltage in normal running conditions, and the vehicle earth.
Claim 7
Dependent Claim
52 words
A battery charging system as claimed in claim 4, in which one end of the resistor chain is connected to the vehicle earth and the other end thereof is connected by a further resistor to the main output of the rectifier and by a diode and a separate lead to the battery.
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) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |