Voltage supply apparatus powered from a vehicular electrical system

摘要

A series regulating transistor supplying voltage to a supply bus from a vehicular battery in which circuitry samples voltage from the supply bus for generating a correction signal for controlling operation of the regulating transistor. A first switching transistor of a starting circuit biases the regulating transistor into a conductive state in response to the connection of the battery to the apparatus and a second switching transistor switches the first switching transistor OFF responsive to the voltage level developed on the supply bus.