Control apparatus for vehicle AC generator

A control apparatus for a vehicle AC generator comprising:

• an AC generator whose output voltage is regulated by controlling a quantity of a field current flowing through a field coil of the AC generator;
• a switching element for performing on/off-control of the field current flowing through said field coil with a predetermined duty ratio;
• voltage detecting means for detecting an output voltage of said AC generator;
• rotation speed detecting means for detecting a rotation speed of said generator;
• and
• control means for gradually increasing a conducting rate of said switching element by gradually increasing said duty ratio in dependence on the detected output voltage, said control means further comprising:
• a smoothing circuit which outputs a discharge voltage, and is operative to smooth the detected voltage of the voltage detecting means and to decrease a discharging time constant as the rotation speed detected by the rotation speed detecting means increases;
• triangular waveform generating means for generating a triangular waveform voltage;
• and
• comparing means for comparing said discharge voltage of said smoothing circuit with said triangular waveform voltage, to thereby output an on/off control signal for the switching element,
• wherein said control means is operative to gradually increase said duty ratio in conformance with an increase in the rotation speed detected by said rotation speed detecting means.

A control apparatus for a vehicle AC generator comprising:

• an AC generator whose output voltage is regulated by controlling a quantity of a field current flowing through a field coil of the AC generator;
• a switching element for performing on/off-control of the field current flowing through said field coil with a predetermined duty ratio;
• voltage detecting means for detecting an output voltage of said AC generator;
• control means for gradually increasing a conducting rate of said switching element by gradually increasing said duty ratio in dependence on the detected output voltage;
• rotation speed detecting means for detecting a rotation speed of said generator,
• wherein the control means further comprises:
• a smoothing circuit operative to smooth the detected voltage of the voltage detecting means and to decrease a discharging time constant as the rotation speed detected by the rotation speed detecting means increases;
• triangular waveform generating means for generating a triangular waveform voltage;
• and
• comparing means for comparing a discharge voltage of said smoothing circuit with said triangular waveform voltage, to thereby output an on/off control signal for the switching element,
• wherein said control means is operative to gradually increase said duty ratio in conformance with an increase in the rotation speed detected by said rotation speed detecting means;
• and
• wherein the smoothing circuit further comprises:
• a constant-current circuit with a current level that increases with an increase in the rotation speed of said generator;
• and
• a smoothing capacitor, wherein a rate at which voltage is discharged from the smoothing capacitor increases as said current value increases.