Abstract: The present invention provides an apparatus for reducing the allowed output current from an electrical device such as a high output capacity vehicle alternator in response to a sensed over temperature condition. In one embodiment, a thermistor is attached to the housing of an alternator to provide temperature sensing capability. As temperature exceeds a temperature set point established by a resistor bridge, op-amps, in combination with a power FET in series with the alternator field windings, act to reduce the allowed current output from the alternator in proportion to the extent the set point temperature has been exceeded. As the alternator temperature returns to below the set point, the output current restriction is reduced such that the allowed current flow is maximized without exceeding the temperature set point.

Abstract: A reference voltage developing circuit that develops a multiple slope reference voltage that is a function of temperature. The circuit has a plurality of base-emitter multipliers each of which includes a transistor and each of which develops an output voltage that is a function of the base-emitter voltage of the transistor of the multiplier. Since the base-emitter voltage varies with changes in temperature, each multiplier circuit develops a voltage that varies with changes in temperature. The multiplier circuits have different multiplier magnitudes to thereby provide temperature dependent output voltages that have different slopes. A voltage selector circuit is connected to the multiplier circuits and it provides an output voltage that corresponds to the higher of the output voltages developed by the multiplier circuits.

Abstract: A voltage regulator for regulating the output voltage of a diode-rectified alternating current generator that supplies the electrical loads on a motor vehicle including the storage battery. The voltage regulator has an up-down counter which is incremented when the output voltage of the generator is below a desired regulated value and is decremented when the output voltage of the generator is above the desired regulating value. The magnitude of the count in the counter is repeatedly sampled and used to determine the on time of a semiconductor switch that is connected in series with the field winding to thereby control the duty cycle of the field voltage pulses. The counter is incremented at a lower rate when the speed of the engine that drives the generator is below a predetermined speed than it is when the speed of the engine is above the predetermined speed. When the generator is not rotating, the up-count of the counter is limited to a predetermined value that provides a minimum field voltage duty cycle.

Abstract: A voltage regulating system for a diode-rectified alternating current generator that supplies the electrical loads on a motor vehicle including charging the storage battery. The voltage regulator has a reference voltage developing circuit that can operate either in a temperature compensated mode or a flat mode. In the temperature compensated mode the reference voltage developed by the circuit varies with temperature and while the circuit is in the flat mode the reference voltage remains substantially constant with changes in temperature. The voltage regulator has a switching transistor connected in series with the field winding of the generator which can operate in a current limiting mode in the event that sensed field current becomes excessive. The voltage regulator includes circuitry for ensuring that the output voltage of the generator properly builds-up when the field winding is initially excited by the battery.

Abstract: A voltage regulator for the battery charging generator of a motor vehicle battery charging system. The regulator is capable of detecting various fault conditions and under certain conditions will latch a fault indicator to a latched energized state. The regulator utilizes a Zener diode as a voltage reference and is arranged to accommodate Zener diodes of varying break down voltages by trimming a resistor of the regulator voltage sensing circuit. The regulator includes an internal voltage regulating device having a regulated output voltage applied to fault detecting comparators. The output voltage of the internal regulating device is a function of the particular break down voltage of the Zener diode.

Abstract: A voltage regulator for the battery charging generator of a motor vehicle battery charging system. The regulator is capable of detecting various fault conditions and under certain conditions will latch a fault indicator to a latched energized state. The regulator utilizes a Zener diode as a voltage reference and is arranged to accommodate Zener diodes of varying break down voltages by trimming a resistor of the regulator voltage sensing circuit. The regulator includes an internal voltage regulating device having a regulated output voltage applied to fault detecting comparators. The output voltage of the internal regulating device is a function of the particular break down voltage of the Zener diode.

Abstract: A voltage regulator for the battery charging generator of a motor vehicle battery charging system. The regulator is capable of detecting various fault conditions and under certain conditions will latch a fault indicator to a latched energized state. The regulator utilizes a Zener diode as a voltage reference and is arranged to accommodate Zener diodes of varying break down voltages by trimming a resistor of the regulator voltage sensing circuit. The regulator includes an internal voltage regulating device having a regulated output voltage applied to fault detecting comparators. The output voltage of the internal regulating device is a function of the particular break down voltage of the Zener diode.

Abstract: A voltage regulator for the battery charging generator of a motor vehicle battery charging system. The regulator is capable of detecting various fault conditions and under certain conditions will latch a fault indicator to a latched energized state. The regulator utilizes a Zener diode as a voltage reference and is arranged to accommodate Zener diodes of varying break down voltages by trimming a resistor of the regulator voltage sensing circuit. The regulator includes an internal voltage regulating device having a regulated output voltage applied to fault detecting comparators. The output voltage of the internal regulating device is a function of the particular break down voltage of the Zener diode.