Multiple voltage alternator system
First Claim
1. A multiple voltage alternator system for directing power between an alternator, a single battery and loads connected thereto which require power at a higher DC voltage and a lower DC voltage, the system comprising:
- a higher DC voltage output;
a lower DC voltage output;
a transformer having first and second windings which allow power to flow bi-directionally therebetween, the first winding having a higher AC voltage when the second winding has a lower AC voltage;
a switching controller that switches at a desired frequency;
a first bi-directional converter controlled by the switching controller and connected to the higher DC voltage output and the first winding of the transformer, the first converter producing the higher DC voltage by rectifying the higher AC voltage of the first winding when power is flowing from the second winding to the first winding of the transformer and the first converter producing the higher AC voltage by chopping the higher DC voltage at the desired frequency when power is flowing from the first winding to the second winding of the transformer; and
a second bi-directional converter operating synchronously with the first converter and controlled by the switching controller to switch at the same frequency as the first converter, the second converter being connected to the lower DC voltage output and the second winding, the second converter producing the lower DC voltage by rectifying the lower AC voltage of the second winding of the transformer when power is flowing from the first winding to the second winding and the second converter producing the lower AC voltage by chopping the lower DC voltage at the desired frequency when power is flowing from the second winding to the first winding of the transformer.
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Accused Products
Abstract
A multiple voltage alternator system for directing power in a vehicle between an alternator, a single battery and loads connected thereto which require power at a higher DC voltage and a lower DC voltage. In one embodiment, first and second bi-directional converters operate synchronously and are coupled together through a transformer having first and second windings. The alternator supplies power directly at one voltage and indirectly through the bi-directional converters at the other voltage when the vehicle engine is running. The battery operates at the opposite voltage from the alternator, preferably at the lower voltage, and directly supplies power at one voltage and indirectly at the other voltage when the alternator is not providing power. In an alternative embodiment the bi-directional converters are coupled through an autotransformer. The system is particularly suitable for use with vehicles having engines with electromagnetically operated valves that require less power when starting and more power at higher engine speeds. In yet another embodiment, one way DC to DC down voltage conversion is provided through a transformer, preferably an autotransformer, and engine valves requiring higher DC voltages at high engine speeds are provided with the lower voltage at engine startup through a lower DC voltage to a higher DC voltage bypass circuit.
50 Citations
25 Claims
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1. A multiple voltage alternator system for directing power between an alternator, a single battery and loads connected thereto which require power at a higher DC voltage and a lower DC voltage, the system comprising:
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a higher DC voltage output; a lower DC voltage output; a transformer having first and second windings which allow power to flow bi-directionally therebetween, the first winding having a higher AC voltage when the second winding has a lower AC voltage; a switching controller that switches at a desired frequency; a first bi-directional converter controlled by the switching controller and connected to the higher DC voltage output and the first winding of the transformer, the first converter producing the higher DC voltage by rectifying the higher AC voltage of the first winding when power is flowing from the second winding to the first winding of the transformer and the first converter producing the higher AC voltage by chopping the higher DC voltage at the desired frequency when power is flowing from the first winding to the second winding of the transformer; and a second bi-directional converter operating synchronously with the first converter and controlled by the switching controller to switch at the same frequency as the first converter, the second converter being connected to the lower DC voltage output and the second winding, the second converter producing the lower DC voltage by rectifying the lower AC voltage of the second winding of the transformer when power is flowing from the first winding to the second winding and the second converter producing the lower AC voltage by chopping the lower DC voltage at the desired frequency when power is flowing from the second winding to the first winding of the transformer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A multiple voltage alternator system comprising:
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a transformer having first and second windings, the first winding producing a higher AC voltage when a lower AC voltage is applied to the second winding and the second winding producing a lower AC voltage when a higher AC voltage is applied to the first winding; a switching controller operating at a desired frequency; a first bi-directional converter connected to the first winding, the first converter including first and second switches forming a first pair of switches and third and fourth switches forming a second pair of switches, the first and second pairs of switches being connected in a bridge configuration and the pairs of switches being oppositely switched by the switching controller at the desired frequency to produce a higher DC voltage by rectifying the higher AC voltage of the first winding when the lower AC voltage is applied to the second winding; and a second bi-directional converter connected to the second winding, the second converter including fifth and sixth switches, the fifth and sixth switches of the second converter being oppositely switched by the switching controller at the same frequency as, and in synchronism with, the first and second pairs of switches of the first converter, the first and second switches of the second converter acting to rectify the lower AC voltage of the second winding when the higher AC voltage is applied to the first winding to produce a lower DC voltage. - View Dependent Claims (17, 18, 19)
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20. A multiple voltage alternator system for directing power between an alternator, a single battery and loads connected thereto which require power at a higher DC voltage and a lower DC voltage, the system comprising:
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a higher DC voltage output; a lower DC voltage output connected to the battery; a switching controller that switches at a desired frequency; an autotransformer; a first bi-directional converter controlled by the switching controller and connected to the autotransformer and the higher DC voltage output, the first bi-directional converter bi-directionally converting between the higher DC voltage and a higher AC voltage on the autotransformer; and a second bi-directional converter controlled by the switching controller and connected to the autotransformer and the lower DC voltage output, the second bi-directional converter operating synchronously with the first converter and bi-directionally converting between the lower DC voltage and a lower AC voltage on the autotransformer.
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21. A multiple voltage alternator system for directing power between an alternator, a single battery and loads connected thereto which require power at a higher DC voltage and a lower DC voltage, the system comprising:
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a higher DC voltage output; a lower DC voltage output connected to the battery; a switching controller that switches at a desired frequency; a transformer for transforming a higher AC voltage to a lower AC voltage; a converter controlled by the switching controller and connected to the transformer and the higher DC voltage output, the converter converting the higher DC voltage to the higher AC voltage on the transformer; a rectifier circuit connected to the transformer, the rectifier circuit rectifying the lower AC voltage to the lower DC voltage to charge the battery; and a low voltage to high voltage bypass circuit connected between the lower DC voltage output and the higher DC voltage output to provide the lower DC voltage to the higher DC voltage output when the alternator is not providing power. - View Dependent Claims (22, 23, 24, 25)
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Specification