Abstract: In a charge/float vehicle electrical system, heavy battery charging is effected during periods of engine deceleration and the float voltage is adjusted so as to maintain the battery state of charge at the level in existence at the initiation of the float mode.

Abstract: A system responsive to the voltage of a motor vehicle battery when the vehicle engine is not running operates to disconnect the battery from the vehicle electrical loads prior to the point at which the battery becomes too discharged to restart the vehicle engine. The apparatus which operates to disconnect the battery from the loads is inhibited if an abrupt battery voltage drop indicative of vehicle entry is sensed, and the inhibit is maintained for a timed period sufficiently long in duration to allow entry of the vehicle and starting of the engine.

Abstract: A voltage regulating system for a generator that supplies the battery and electrical loads on a motor vehicle. The system includes a load response control for detecting whenever a substantial electrical load is applied to the generator tending to cause a drop in generator output voltage and when such a condition is detected field current is controlled to gradually increase field current from some value. The load response control includes means for storing an electrical signal that corresponds to generator field current and for utilizing this stored value to set generator field current at a value corresponding to a field current that occurred just prior to the detected drop in voltage and then increasing field current slowly from this value.

Abstract: A motor vehicle electrical system having a charge mode of operation wherein the motor vehicle battery receives charging current at a temperature compensated voltage from an engine-driven generator, and a float mode operation wherein the battery charging current is reduced to a low value, sufficient only to prevent self-discharge of the battery. The charge and float modes of operation are alternately engaged as a function of the battery state of charge. During the charge mode of operation, a sufficiently high state of charge is detected as a function of the magnitude of the charging current, and during the float mode of operation, a depleted state of charge is detected as a function of the battery voltage. A timer provides a periodic return to the charge mode of operation to sample the battery state of charge.

Abstract: The output signal produced by a two input electrical circuit element of the type which produces opposite polarity output signals upon the application of the same polarity input signal to respective ones of the input terminals is applied to the control electrode of a switching transistor which, when conductive, is effective to complete the energizing circuit of an internal combustion engine cranking motor. An electrical bias signal of a selected polarity is applied to the one of the input terminals of this circuit element which will result in an output signal of the polarity which will trigger the switching transistor conductive through the current carrying electrodes thereof.

Abstract: A circuit for indicating faults in a storage battery charging system of the type including an alternator having a field winding and a rectifier circuit having respective battery charging and alternator field winding energizing output circuit terminals. A differential amplifier circuit, to which is applied normally equal reference sensing potentials which become unbalanced with alternator faults, produces a first fault indicating signal in the event of an alternator malfunction and a transistor having the control electrode connected to the rectifier circuit field winding energizing output circuit terminal produces a second fault indicating signal in the event of a failure of one of the diodes in the rectifier field winding energizing output circuit. These fault indicating signals trigger a transistor conductive to complete an energizing circuit for a fault indicating device.

Abstract: A circuit for indicating faults in a storage battery charging system of the type including a voltage regulator controlled alternator field winding switching transistor and a rectifier circuit having a diode trio which supplies alternator field winding energizing current. A differential amplifier circuit, to which is applied normally equal reference and sensing potentials which become unbalanced with alternator faults, produces a first fault indicating signal in the event of an alternator malfunction and a transistor having the control electrode connected to the output of the field winding diode trio of the rectifier circuit produces a second fault indicating signal in the event of a failure of one of these diodes. These fault indicating signals trigger a transistor conductive to complete an energizing circuit for a fault indicating device. Additionally, an oscillator flashes the fault indicating device "on" and "off" in the event of a voltage regulator failure.