Battery charging systems for road vehicles
First Claim
1. A battery charing system for a road vehicle comprising an alternator, a rectifier connecting the alternator to a main battery for charging thereof by the alternator, a voltage regulator connected to the alternator and operating to control the output voltage of the alternator, and a d.c. to d.c. converter connecting the main battery to an auxiliary battery which is in series with the main battery, the d.c. to d.c. converter including a pair of semi-conductor switching elements, an auto-transformer having a pair of main windings, each connected at one end to one terminal of the main battery and connected at its other end through a respective one of said semi-conductor switching elements to the other terminal of the main battery, said switching elements forming part of an oscillator so that the switching elements are turned on alternately, a diode, and at least one further winding connected in series with said diode between said other end of one of the main windings and a terminal of the auxiliary battery.
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Accused Products
Abstract
A road vehicle battery charging system for a dual voltage electrical supply includes a conventional alternator/rectifier assembly for charging the main battery and a d.c. to d.c. converter connected to charge an auxiliary battery in series with the main battery. The converter includes an autotransformer with primary windings in series with respective transistors across the main battery and further windings connecting the transistor collectors in series with diodes to the auxiliary battery. The transistors form part of an oscillator which produces an a.c. waveform with a peak-to-peak voltage slightly less than twice the main battery voltage--the deficiency being made up by virtue of the further windings.
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Citations
11 Claims
- 1. A battery charing system for a road vehicle comprising an alternator, a rectifier connecting the alternator to a main battery for charging thereof by the alternator, a voltage regulator connected to the alternator and operating to control the output voltage of the alternator, and a d.c. to d.c. converter connecting the main battery to an auxiliary battery which is in series with the main battery, the d.c. to d.c. converter including a pair of semi-conductor switching elements, an auto-transformer having a pair of main windings, each connected at one end to one terminal of the main battery and connected at its other end through a respective one of said semi-conductor switching elements to the other terminal of the main battery, said switching elements forming part of an oscillator so that the switching elements are turned on alternately, a diode, and at least one further winding connected in series with said diode between said other end of one of the main windings and a terminal of the auxiliary battery.
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11. a battery charging system for a road vehicle comprising the combination of an alternator, a rectifier connecting the alternator to a main battery for charging thereof by the alternator, a voltage regulator connected to the alternator and controlling the output voltage of the alternator, and a d.c. to d.c. converter connecting the main battery to an auxiliary battery which is in series with the main battery, said converter including a transformer having input windings and output windings, a first choke connecting a common point on said input windings to one terminal of the main battery, a first pair of capacitors connecting opposite ends of said first choke to the other terminal of the main battery, an oscillator circuit connecting said input windings to the other terminal of the main battery and including a pair of switching elements which are turned on and off alternately, diode means connecting the output windings to an output terminal, a second choke connecting said output terminal to the auxiliary battery, and a second pair of capacitors one of which connects said output terminal to said common point on the input windings and the other of which connects the other end of the second choke to said other terminal of the main battery.
Specification