Charging generator control for vehicles

Apparatus for controlling charging of a battery comprising:

• a reference voltage source which generates a reference voltage;
• a deviation signal output circuit connected to said reference voltage source and to an output of said battery, and having an output signal indicative of a difference between said reference voltage and an output voltage of said battery;
• a voltage scaling circuit connected to receive said output signal from said deviation signal output circuit;
• an integrator circuit connected to receive said output signal from said deviation signal output circuit;
• a variable reference signal generator;
• means for generating a control signal when an output from said variable reference signal generator reaches a level which is equal to or greater than a lower of instantaneous values of output signals from said voltage scaling circuit and said integrator circuit;
• a battery charging apparatus for charging said battery;
• and
• means responsive to said control signal for controlling a duty cycle of said battery charging apparatus.

Method of controlling charging of a battery, comprising the steps of:

• generating a deviation signal having a magnitude which is indicative of magnitude of a difference between an output voltage of said battery and a reference voltage;
• scaling said deviation signal in a voltage scaling circuit;
• integrating said deviation signal;
• comparing instantaneous values of results of said scaling step and said integrating step;
• and
• controlling a duty cycle of field current in a battery charging apparatus as a function of magnitude of a lower of said instantaneous values.

A charging controller for vehicles comprising:

• a field coil for generation a rotating magnetic field, said field coil being driven in accordance with rotation of an engine;
• an armature having an armature coil for generating a current in response to said rotating magnetic field, and for charging a battery through a rectifier;
• a voltage detection circuit for detecting one of voltage of said battery and voltage of said rectifier;
• a set voltage circuit for generating a reference voltage;
• a differential signal output circuit for outputting a signal indicative of a difference between an output voltage of said voltage detection circuit and said reference voltage;
• a waveform generator for generating a voltage waveform which rises and falls at a preset cycle within a fixed voltage range;
• an integrating circuit coupled to an output voltage of said differential signal output circuit, said integrating circuit having a time constant longer than a time constant of a rotor of said armature;
• a voltage divider circuit for dividing an output voltage of said differential signal output circuit;
• a comparator coupled to receive at one output thereof a voltage equal to a constant plus a lower of an output voltage of said integrating circuit and an output voltage of said voltage divider circuit, and to receive at another input thereof an output of said waveform generator;
• and
• a current control circuit for controlling current supplied to said field coil in response to an output of said comparator.

A charging controller for vehicles comprising:

• a field coil for generation a rotating magnetic field, said field coil being driven in accordance with rotation of an engine;
• an armature having an armature coil for generating a current in response to said rotating magnetic field, and for charging a battery through a rectifier;
• a voltage detection circuit for detecting one of voltage of said battery and voltage of said rectifier;
• a set voltage circuit for generating a reference voltage;
• a differential signal output circuit for outputting a signal indicative of a difference between an output voltage of said voltage detection circuit and said reference voltage;
• a sawtooth signal generator circuit for outputting a sawtooth signal at preset cycles within a fixed voltage range;
• an integrating circuit coupled to receive an output voltage of said differential signal output circuit, said integrating circuit having a time constant longer than a time constant of a rotor of said armature;
• a voltage divider circuit for dividing an output voltage of said differential signal output circuit;
• a first comparator coupled to receive an output voltage of said integrating circuit and said sawtooth signal;
• a second comparator coupled to receive an output voltage of said voltage divider circuit and said sawtooth signal;
• a minimum current flow rate passage circuit for outputting a reduced current flow rate in response to comparing the output of said first comparator with the output of said second comparator;
• and
• a current control circuit for controlling the current to be supplied to said field coil in response to the output of said minimum current flow rate passage circuit.