METHOD FOR CONTROLLING CONSTANT VOLTAGE AND APPARATUS THEREOF

摘要

A method and an apparatus for controlling a constant voltage for vehicles are provided to extend lifetime of a vehicle head lamp by uniformly maintaining a voltage supplied to a load from a battery. An input voltage detecting part(12) receives an input voltage signal from a power source. An input current detecting part(14) receives an input current signal from the power source. A voltage output part(16) outputs the inputted voltage signal to outside. A current output part(18) outputs the inputted current signal to outside. An over current control part(30) shuts down a whole circuit in case the input current signal is more than a maximum tolerance current. A control part(15) applies the input current signal to the voltage output part and the current output part in case the input current signal is less than the maximum tolerance current. The control part applies the input current signal to a FET(Field Effect Transistor)(20) and the over current control part in case the input current signal is more than the maximum tolerance current.