Voltage control apparatus of alternator

Abstract

In a voltage control apparatus of an alternator mounted on a vehicle, the parameter and the equation, which are established based upon the power generation characteristic and the electromagnetic specification of the alternator, are not required, and both an ON-duty rate of an ON/OFF logic of a voltage applied to an energizing coil and a logic frequency can be established under stable condition within a preselected frequency range. The alternator voltage control apparatus is arranged by employing: a first logic output means for comparing a voltage generated by the alternator with a target voltage to obtain a magnitude logic which is outputted as a first ON/OFF logic; and a second logic output means for outputting as a second ON/OFF logic, a PWM internal output logic in which an ON-duty rate is increased/decreased based on the first ON/OFF logic by an increased/decreased amount defined by considering a time constant of the energizing coil. In this alternator voltage control apparatus, a logically processed result between the first ON/OFF logic and the second ON/OFF logic is used as an ON/OFF logic of a voltage application to the energizing coil.

Dependencies are inferred from the claim text.