Abstract: In a vehicle generator control which detects an abnormal operating condition of a generator of a vehicle, and includes a transistor which drives a charging lamp to emit a warning indication when such a condition is detected, with the value of a quantity indicative of the flow of current through the charging lamp drive transistor being compared with a reference value, and with the transistor being set in a non-conducting state if the reference value is exceeded, a succession of respectively decreasing reference values is periodically generated. A timing of an initial flow of current through the charging lamp is controlled to be synchronized with the start of such a succession, so that the peak value of an initial surge current which flows through the charging lamp drive transistor is compared with the highest reference value. Complete protection can thereby be established for the charging lamp drive transistor against a flow of short-circuit current which would exceed any of the reference values.

Abstract: A generation control system for a vehicle includes an ac generator, a field current control unit that controls the duty ratio of field current of the ac generator, a field current detector, a load current detector, a generator rotation speed detector, a driving-torque-increase calculator that calculates a predicted increase in driving torque of the ac generator from increase in the current supplied to an electric load. The driving-torque-increase calculator includes first output current calculator that calculates present output current of the ac generator from the generator's rotation speed and the field current and second output current calculator that calculates predicted output current of the ac generator from the first output current and the increase in the current supplied to the electric load. A predicted increase in driving torque of the ac generator is calculated from a difference between the present driving torque and a driving torque that corresponds to the predicted output current.

Abstract: A control apparatus such as an ECU, that controls the generator of a vehicle, measures the engine rotation speed and generator rotation speed while the engine is idling, and calculates and stores the ratio of the speed values. Thereafter when the vehicle is being driven and the current value of generator rotation speed is required, it is calculated based on the stored ratio value and the currently measured speed of the engine. The processing load on the ECU is thereby reduced, since generator rotation speed measurement processing is performed only in the idling condition.

Abstract: In an alternator, failure in a power supply line connected to an output terminal of a rectifier is detected. Upon detection of a failure in this power supply line, power generation is suppressed for a predetermined period that is longer than the time constant of a field winding of the alternator. Preferably, a high voltage pulse is detected to discriminate a first condition where a single high voltage pulse is generated when an electrical load connected to the power supply line is cut off and a second condition where a high voltage pulse is repeatedly and frequently generated when a failure occurs in the power supply line. Only when the second condition is discriminated, power generation suppression control of the alternator is conducted.

Abstract: In an alternator, failure in a power supply line connected to an output terminal of a rectifier is detected. Upon detection of a failure in this power supply line, power generation is suppressed for a predetermined period that is longer than the time constant of a field winding of the alternator. Preferably, a high voltage pulse is detected to discriminate a first condition where a single high voltage pulse is generated when an electrical load connected to the power supply line is cut off and a second condition where a high voltage pulse is repeatedly and frequently generated when a failure occurs in the power supply line. Only when the second condition is discriminated, power generation suppression control of the alternator is conducted.

Abstract: In an alternator, failure in a power supply line connected to an output terminal of a rectifier is detected. Upon detection of a failure in this power supply line, power generation is suppressed for a predetermined period that is longer than the time constant of a field winding of the alternator. Preferably, a high voltage pulse is detected to discriminate a first condition where a single high voltage pulse is generated when an electrical load connected to the power supply line is cut off and a second condition where a high voltage pulse is repeatedly and frequently generated when a failure occurs in the power supply line. Only when the second condition is discriminated, power generation suppression control of the alternator is conducted.

Abstract: A voltage regulator is comprised of a semiconductor element for controlling current supplied to a field coil, a flywheel element, a generation voltage regulation circuit for controlling the semiconductor element, and a switching capacity control circuit for controlling a current-switching capacity during a former stage of a turn-off transition period of the semiconductor element to be larger than that during the latter stage of the turn-off transition period. Accordingly, the current change rate can be reduced, so that surge voltage and electro-magnetic wave can be reduced.

Abstract: A battery charging system is provided for an excellent engine starting. The battery charging system includes a generator control unit for controlling output voltage of the generator and a commanding unit for providing a command pulse signal. The generator control unit includes a command pulse signal's duty-ratio detecting circuit, a generator output power limiting circuit, a voltage regulator and an activation circuit for activating the output power limiting circuit when the duty-ratio falls within a predetermined ratio range.

Abstract: In a vehicle generator control which detects an abnormal operating condition of a generator of a vehicle, and includes a transistor which drives a charging lamp to emit a warning indication when such a condition is detected, with the value of a quantity indicative of the flow of current through the charging lamp drive transistor being compared with a reference value, and with the transistor being set in a non-conducting state if the reference value is exceeded, a succession of respectively decreasing reference values is periodically generated. A timing of an initial flow of current through the charging lamp is controlled to be synchronized with the start of such a succession, so that the peak value of an initial surge current which flows through the charging lamp drive transistor is compared with the highest reference value. Complete protection can thereby be established for the charging lamp drive transistor against a flow of short-circuit current which would exceed any of the reference values.

Abstract: A battery charging system is provided for an excellent engine starting. The battery charging system includes a generator control unit for controlling output voltage of the generator and a commanding unit for providing a command pulse signal. The generator control unit includes a command pulse signal's duty-ratio detecting circuit, a generator output power limiting circuit, a voltage regulator and an activation circuit for activating the output power limiting circuit when the duty-ratio falls within a predetermined ratio range.

Abstract: A voltage regulator of a vehicle AC generator includes a switching element connected between a battery and a field coil, a control circuit for controlling the switching element according to battery voltage, a power circuit for supplying the control circuit with a constant voltage and a reverse-current blocking diode having an anode connected through an outside power line to the battery and a cathode connected to the power circuit. Even if a large negative surge voltage is generated in a power line connected to a battery, and applied to the power circuit, the output voltage, i.e. VDD, does not widely fluctuate, so that devices included in the voltage regulator, such as a comparator or an oscillator, can operate properly.

Abstract: A voltage regulator is comprised of a semiconductor element for controlling current supplied to a field coil, a flywheel element, a generation voltage regulation circuit for controlling the semiconductor element, and a switching capacity control circuit for controlling a current-switching capacity during a former stage of a turn-off transition period of the semiconductor element to be larger than that during the latter stage of the turn-off transition period. Accordingly, the current change rate can be reduced, so that surge voltage and electromagnetic wave can be reduced.

Abstract: In an alternator, failure in a power supply line connected to an output terminal of a rectifier is detected. Upon detection of a failure in this power supply line, power generation is suppressed for a predetermined period that is longer than the time constant of a field winding of the alternator. Preferably, a high voltage pulse is detected to discriminate a first condition where a single high voltage pulse is generated when an electrical load connected to the power supply line is cut off and a second condition where a high voltage pulse is repeatedly and frequently generated when a failure occurs in the power supply line. Only when the second condition is discriminated, power generation suppression control of the alternator is conducted.

Abstract: A voltage regulator of a vehicle AC generator includes a switching element connected between a battery and a field coil, a control circuit for controlling the switching element according to battery voltage, a power circuit for supplying the control circuit with a constant voltage and a reverse-current blocking diode having an anode connected through an outside power line to the battery and a cathode connected to the power circuit. Even if a large negative surge voltage is generated in a power line connected to a battery, and applied to the power circuit, the output voltage, i.e. VDD, does not widely fluctuate, so that devices included in the voltage regulator, such as a comparator or an oscillator, can operate properly.

Abstract: A permanent magnet made of ferrite magnet material used for a generator may be irreversibly demagnetized by a factor such as current supplied to a field coil, temperature of the permanent magnet and/or output current of an armature coil. When the field current exceeds a preset value, and also the output current exceeds a preset value, the field current is limited to prevent the irreversible demagnetization. Thus, the irreversible demagnetization of the permanent magnet can be prevented, while ensuring a sufficient amount of the output power. It is also effective that the field current or armature current is limited when the temperature of the permanent magnet is in a range of possible irreversible demagnetization.

Abstract: A control device for a vehicle alternator having a field coil, and an auxiliary permanent magnet. The control device includes voltage regulator, a generation-condition detecting circuit having a frequency sensor and a comparator for comparing a frequency of the output voltage with a reference value and a power source circuit for supplying electric power to the generation-condition detecting circuit when the output voltage becomes equal to or higher than a voltage that is generated without the field current. The generation-condition detecting circuit allows the voltage regulator to supply the field coil with controlled electric current only when the frequency of the output voltage is higher than the reference value.

Abstract: An inductive load driving apparatus for controlling current supplied from a battery to an inductor such as a generator field coil is composed of a first N-channel MOSFET switching element connected between a high-side terminal of the inductor and a high-side terminal of the battery, a second N-channel MOSFET switching element connected in parallel with the inductive load and a protection circuit having a back-flow current detecting element turning off the second N-channel MOSFET switching element when the inductor does not generate back-flow current. The second N-channel MOSFET switching element is turned on when the first N-channel MOSFET switching element is turned off and turned off when the first switching element is turned on. The first and second N-channel MOSFET switching elements are disposed integrally with each other on a semiconductor chip.

Abstract: Duty ratio of a power switching transistor connected to the field coil is controlled according to whether or not a high-power load is connected. When the high power load is not connected, the duty ratio is made 60%, for example, so that excessive power not generated. On the other hand, when the high power load is connected, the duty ratio is increased to 100% so that full power is generated by the generator. The power switching transistor is also controlled according to the battery voltage in a well known manner.

Abstract: A control voltage setting circuit 31 provides one of a pair of control voltages when one of a pair of command signals are transmitted from an upper control unit 4 which is disposed outside the alternator. The command signals correspond respectively to upper and lower desired output voltages of the alternator. A voltage regulation circuit 32 makes the alternator provide an alternator output voltage according to one of the control signal. When a pair of the command signals are generated alternately at a cycle shorter than a cycle decided by the response time of the alternator, the control voltage setting circuit 31 provides an alternating control signal so that the alternator 2 generates a middle voltage between the upper and lower desired voltages.

Abstract: A generator for vehicle is connected to an end of a transmitting wire through a generator-side signal transmitting and receiving circuit which has a transistor and a comparator. An ECU is connected to the other end of the transmitting wire through a vehicle-side signal transmitting and receiving circuit which has a switching transistor and a comparator. The comparator receives frequency signals from the transistor, and the comparator receives a voltage signal from the transistor. Thus, the generator control signal and the generator condition signal are transmitted by the same transmitting wire.