| 摘要 |
A dual voltage power supply is disclosed for vehicles equipped with a DC generator, a single storage battery, a low voltage load circuit including the storage battery, and a high voltage load circuit including load devices designed to be powered by voltages higher than the battery voltage. At times when higher voltage power is required a low voltage regulator that includes a high current semiconductor switch converts power at the generator output voltage to power at a lower voltage for charging the battery and supplying the low voltage load circuit. There is a single voltage mode of operation when higher voltage power is not required in which the alternator is regulated to supply power at the voltage required by the low voltage load circuit and the high current semiconductor switch is held in its closed state to directly connect the generator output with the low voltage load circuit. The low voltage regulator is a switching DC to DC voltage converter with an N channel mosfet power transistor switch controlled by an improved driver circuit. The driver circuit has a floating totem pole output and a capacitively coupled input and is assisted by a pull down circuit and current from a low current supply. An input accepts a signal controlling whether the system operates in dual or single voltage mode. One or more transient absorbing semiconductors and a circuit for rapidly decreasing rotor current limit the duration of alternator overvoltage.
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