Abstract: A generator control system for a vehicle includes an AC generator, a switch connected in series with a field coil, a voltage regulator unit, a field-current restricting unit for controlling the switch to turn on or off, a forbidding unit having a command signal input terminal for forbidding operation of the field-current restricting unit when a voltage higher than a predetermined regulation voltage is applied to the command signal input terminal.

Abstract: A voltage regulator of a vehicle AC generator includes a rotor having a plurality of magnetic poles, a field coil for polarizing magnetic poles, an armature having an armature core with a plurality of phase windings for generating AC voltage under the influence of rotating magnetic field provided by the rotor and a full-wave rectifier for converting the AC voltage into DC voltage. The voltage regulator is comprised of a circuit for detecting phase voltage of one of the phase windings, and a comparator for comparing the phase voltage with a variable threshold level formed from the phase voltage and providing an output signal. Even if the phase voltage is biased by a DC bias voltage due to leak in the armature, the rotation of the rotor can be detected.

Abstract: A vehicle alternator control device has a power transistor, a flywheel diode, a voltage control circuit, a primary power supply circuit, and a secondary power supply circuit. When the alternator starts rotation, the secondary power supply circuit drives the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed higher than an engine idling speed. When the engine stops and the speed of the alternator drops, the secondary power supply circuit stops the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed below the engine idling speed.

Abstract: A voltage regulating system of an AC generator for charging a battery of a nominal voltage includes a rotor having magnetic poles, a field coil, an armature winding, a full-wave rectifier unit connected to the armature winding, a rotation detection unit, a voltage control unit for controlling current supplied to the field coil. The rotation detection unit includes a comparator connected to the armature winding, a first circuit for providing a first threshold voltage that is higher than negative side voltage of the battery and lower than a half of the nominal battery voltage and a second circuit for providing a second threshold voltage that is lower than the nominal voltage and higher than a half of the nominal voltage. The comparator compares the output voltage with one of the first threshold voltage and second threshold voltage. The above structure makes rotation detection accurate and easy even if leak current exist in the armature winding.

Abstract: A generator control system for a vehicle includes an AC generator, a switch connected in series with a field coil, a voltage regulator unit, a field-current restricting unit for controlling the switch to turn on or off, a forbidding unit having a command signal input terminal for forbidding operation of the field-current restricting unit when a voltage higher than a predetermined regulation voltage is applied to the command signal input terminal.

Abstract: A vehicle alternator control device has a power transistor, a flywheel diode, a voltage control circuit, a primary power supply circuit, and a secondary power supply circuit. When the alternator starts rotation, the secondary power supply circuit drives the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed higher than an engine idling speed. When the engine stops and the speed of the alternator drops, the secondary power supply circuit stops the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed below the engine idling speed.

Abstract: A voltage regulating system of an AC generator for charging a battery of a nominal voltage includes a rotor having magnetic poles, a field coil, an armature winding, a full-wave rectifier unit connected to the armature winding, a rotation detection unit, a voltage control unit for controlling current supplied to the field coil. The rotation detection unit includes a comparator connected to the armature winding, a first circuit for providing a first threshold voltage that is higher than negative side voltage of the battery and lower than a half of the nominal battery voltage and a second circuit for providing a second threshold voltage that is lower than the nominal voltage and higher than a half of the nominal voltage. The comparator compares the output voltage with one of the first threshold voltage and second threshold voltage. The above structure makes rotation detection accurate and easy even if leak current exist in the armature winding.

Abstract: A voltage regulator of a vehicle AC generator includes a rotor having a plurality of magnetic poles, a field coil for polarizing magnetic poles, an armature having an armature core with a plurality of phase windings for generating AC voltage under the influence of rotating magnetic field provided by the rotor and a full-wave rectifier for converting the AC voltage into DC voltage. The voltage regulator is comprised of a circuit for detecting phase voltage of one of the phase windings, and a comparator for comparing the phase voltage with a variable threshold level formed from the phase voltage and providing an output signal. Even if the phase voltage is biased by a DC bias voltage due to leak in the armature, the rotation of the rotor can be detected.