Abstract: A protection circuit for a charging generator against a short-circuit of a field winding of an a.c. generator included therein is disclosed, in which an output transistor of a voltage regulator of the charging generator is on-off controlled when a collector current of said output transistor exceeds a predetermined high value.

Abstract: A control apparatus for a vehicular charging generator utilizing various sensors which detect an unstable rotation during the starting of an engine, the acceleration/deceleration condition of the engine, an overload condition of the engine etc. to regulate the output voltage of the generator by a micro-computer, whereby the rotation of the engine is stabilized and the acceleration performance is enhanced due to a reduction of the load of the generator while and over-discharge of the battery is effectively compensated. Also, various abnormal conditions are detected by the sensors and indicated.

Abstract: A control apparatus incorporated in a charging generator for controlling interruption of an exciting current supplied to a field winding of the charging generator comprises a power transistor for intermittently interrupting the exciting current, a voltage detecting circuit for controlling on-off of the power transistor depending on the voltage generated by the charging generator, a current detecting circuit for detecting an initial exciting current supplied to the field winding until the charging generator generates an output voltage high enough for starting its charging operation, and a circuit for turning off the power transistor as soon as the value of the current detected by the current detecting circuit exceeds a predetermined setting.

Abstract: Apparatus for use in an electrical power generating system including a generator for supplying an A.C. output voltage to a load on a set of lines and a circuit responsive to the A.C. output voltage for producing a regulating voltage, the generator having a winding the D.C. energization of which controls the A.C. output voltage. The apparatus controls the energization of the winding and includes a switching circuit adapted to be connected across a resistance and which when rendered conductive bypasses the resistance to couple the voltage regulating circuit to the winding with negligible loss of energy. The switching circuit is combined with a circuit that produces a signal when an increase in the A.C. output voltage exceeding a preselected parameter occurs, and with another circuit that renders the switching circuit nonconductive in response to the signal thereby causing the resistance to consume energy from the winding. Methods of operation of the apparatus are also described.

Abstract: An electric synchronous machine is excited via rotating rectifiers by an exciter machine. To this end, the three-phase winding of the exciter machine is connected to two Y-connected rectifiers having different current conduction directions. One end of the field winding of the synchronous machine is connected to the central point of the three-phase winding. In addition, there is provided between the Y-point of the rectifiers and the other end of the field winding one thyristor each, to the control electrodes of which a parallel-connected voltage sensitive firing device is coupled. Furthermore, stationary electrical elements are connected to the exciter device via switches and auxiliary slip rings and liftable brushes.

Abstract: A surge voltage produced by intermittent operation of a voltage regulating device 5 is suppressed by providing a second power source 10 for exciting an alternating current generator.

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: The present invention is directed to an automatic voltage regulating system for an electric generator comprising a detection coil for detecting the output voltage of an AC generator. The voltage regulating system includes a detection circuit comprising a rectifying circuit for rectifying the output voltage of the detection coil, a smoothing circuit coupled to the detection circuit for smoothing the output voltage and a regulating circuit coupled to the output of the smoothing circuit for shifting the voltage load thereof, wherein the regulating circuit shifts the level of the voltage in the smoothing circuit by comparing the voltage in the rectifying circuit with the predetermined voltage to control the field current during the period of the shifting of the voltage level.

Abstract: A battery charging system for a dual-voltage motor vehicle electrical system that has a pair of series-connected batteries that can energize an electric cranking motor. One of the batteries is charged from a diode-rectified alternating current generator. A voltage regulator regulates the output voltage of the generator and includes a switching means connected in series with the field winding of the generator to control field current. The other battery is charged by field discharge current that is produced by the voltage induced in the generator field winding when the switching means is switched to a nonconductive state.

Abstract: A variable-speed constant-frequency alternator compensating for changes in speed of the prime mover by electromagnetically rotating the rotor's magnetic poles around the rotor. If the prime mover has a rotational speed above or below that required to produce the desired output frequency, the magnetic poles rotate about the rotor in a forward or reverse direction, respectively. To connect the alternator to an external a.c. source, the alternator's controls match its output to the precise amplitude frequency, and phase of the external source. The rotor, for each magnetic pole pair, includes three windings. Three-phase power in these windings, produces the magnetic pole pair and rotates it relative to the rotor. Each winding couples to a flopper circuit having k sets of resistances. The resistances, taken in turn, have an inverse proportionality to the magnitude of the desired sine wave for the three-phase current in the rotor's windings.

Abstract: This invention relates an AC generator comprising a stator coil, a field coil, a pole core for inducing an output voltage to the stator coil, and a voltage regulator for controlling the output voltage. The field coil is wound in either of such directions as to reduce or increase the magnetic flux formed by the pole core. The voltage regulator controls the output voltage to a predetermined value by passing or breaking the current to the field coil. The voltage regulator thus operates to disconnect the field coil when the output voltage is not within a specified range.

Abstract: An alternating current (AC) generator of the type used in vehicular applications and driven by the vehicle engine has a stator winding and a field winding wherein the electrical resistance of the field winding varies as a function of temperature. An exciting current intermittently is allowed to flow through the field winding which induces a current in the stator winding. The output of the stator is rectified and used to charge the vehicle battery. The invention comprises inclusion of field winding current compensation apparatus which varies as a function of temperature to reduce undesired field winding current variations due to temperature which results in improvements of power output and stabilized generator driving torque.

Abstract: This invention relates to a shorted diode protection system for a brushless alternating current generator of the type having an energizeable exciter field winding. The system includes a circuit arrangement for sensing the voltage difference across the exciter field and pairing the voltage difference with generator load current to thereby provide an output signal that falls within a predictable range of values over a normal generator load current range. The output signal is of such a nature that it falls within a higher range of values upon the occurrence of a shorted diode. Another circuit arrangement is responsive to the output signal such that whenever the output signal exceeds a preset value over the normal load current range, an output is generated that operates to cause the interruption of the exciter field.

Abstract: A simplified static excitation system for a fluid-cooled dynamoelectric machine comprises a potential source excitation winding disposed in the stator slots, the winding being responsive to the fundamental frequency of the generator air-gap magnetic flux. The excitation system further comprises transformer means coupling the excitation winding to rectification means which is coupled to the rotating field windings so as to provide direct electric current thereto. The transformer means is preferably disposed within the cooling fluid of the machine.

Abstract: A voltage regulator for aircraft generators controls generator output voltage by controlling exciter field current. Exciter field current sensors and generator output voltage sensors produce control signals which are proportional to exciter field current and generator voltage. These signals are combined and compared with a reference voltage signal by a comparator. A current controller regulates exciter field current in response to the comparator output.

Abstract: A stability control system for a free piston Stirling engine/alternator power unit whose engine power is an exponential function on the engine piston stroke and whose alternator power demand is also an exponential function of the piston stroke, and wherein the engine exponent is normally equal to or greater than the alternator exponent, includes a connection through a rectifier between the alternator output terminals and the alternator field windings. This increases the alternator exponent above the engine exponent to make the system stable. The large time constant of the field winding inductance, which would tend to slow the response time during transients, can be avoided by adding a suitable resistance in series with the field winding.

Abstract: A device for exciting a master generator of self-contained power units for transportation facilities comprises a master generator with a first excitation winding, an auxiliary exciter generator with a second excitation winding, an exciting current regulator, and an independent d-c source. One of the leads of the first excitation winding of the master generator is electrically coupled to a respective d-c lead of the auxiliary exciter generator through its second excitation winding connected accordantly in series with the first excitation winding of the master generator.

Abstract: The alternator has a stator (12) with a rotor (10) mounted for rotation therein. The armature and field windings (20, 22, 24; 18) are both carried on the stator. The rotor is mechanically driven so as to rotate within the stator. Both the rotor and stator have poles (14; 16) formed at regular spacings on facing surfaces thereof so that as the rotor is rotated, rotor poles rotate past the field poles which are formed on the stator. The rotor poles are regularly spaced about the rotor such that at certain rotor positions all rotor poles are opposed to alternate field poles. Field coils (18a, 18b) are provided, each wound about a corresponding one of the field poles. An excitation circuit (FIG. 4) applies an excitation potential to the field coils such that field coils about adjacent field poles produce oppositely directed magnetic fields. The polarity of the this excitation potential is reversed each time the rotor poles become opposed to alternate field poles.

Abstract: A battery charging system includes an alternator with a rectifier connecting the alternator output to the battery. A voltage rectifier controls the current in the alternator field winding in accordance with the battery voltage. A transistor switch in the voltage regulator controls the bias current to the output stage of the regulator and is in turn controlled by a differential amplifier through a diode pump. The differential amplifier is connected to detect the presence of an a.c. on one phase of the alternator and causes the transistor to be switched off, disabling the output stage of the regulator, whenever no a.c. signal is present.

Abstract: An interface circuit for standard voltage regulator circuits that may be employed as an add-on component in an automotive electrical system for providing voltage regulation of the vehicle alternator in accordance with a given reference voltage that is in addition to the normal battery voltage regulation. The interface circuit includes a current control switching device coupled in the current path of the alternator field winding, and a control network responsive to the alternator output and the given reference voltage for operating said switching device in a duty cycle fashion so as to superimpose the additional regulation of the alternator voltage upon its normal battery regulation.

Abstract: In an a.c. generating means exciting method, the exciting windings are wound on the stationary core on which the armature winding has been wound, in such a manner that the exciting windings are delta-connected to one another with the two ends open, and the zero phase current obtained from the two open ends of the delta-connected exciting windings and the phase current obtained from the exciting windings are combined and subjected to rectification to provide a direct current which is utilized to excite the field winding, whereby the field control is carried out in response to the increasing load current and the transient characteristic of the a.c. generating means is improved.

Abstract: A voltage regulator for an AC generator which supplies power to multiple loads at different voltage levels. The magnitude of the multiple voltages and other controlled variables such as per unit current are sensed and individual field currents are generated. A single field current is selected from the individual field currents as a function of the magnitude of a selected voltage and the per unit current and applied to the exciter field of the generator for accurate control of the output voltages.

Abstract: An automatic voltage regulator comprises means for monitoring the voltage of an alternator with a voltage crossover detector and a pulse generator so that a train of output control pulses are produced which are controlled in their mark to space ratio by the output of a circuit which senses the amplitude of the alternator output voltage.

Abstract: A field regulating circuit for a brushless alternator or the like in which a field winding is disposed on a rotor and energized from the secondary winding of a rotary transformer which has its primary winding connected to be energized from a circuit controlled by an oscillator and wherein the frequency of the oscillator is varied in response to a voltage sensing circuit providing a potential which varies with the output of the alternator, the output of the oscillator effecting the generation of first and second pulse trains with the trains being 180.degree. out of phase and effecting energization of the primary of the rotary transformer by current pulses of a fixed width with the current pulses caused by the first and second pulse trains flowing in different directions through the primary winding of the brushless transformer, the pulse trains have pulses of fixed duration which is substantially equal to a half period of the oscillation for the frequency of the oscillator for supplying full field current.

Abstract: For detecting electrical overloads in a traction vehicle propulsion system wherein the output of a prime mover-driven electric generator is controlled by varying the on-off duty cycle of an intermittently conductive switch connected in series with a field winding of the generator excitation means, monitoring means is connected across the field switch to produce an output signal in response to the field switch being continuously conductive for an abnormally long period of time which is indicative of an over-excited condition.

Abstract: A resistor, a DC source and a current converter are connected in series between one terminal of the field winding and the ground. When a ground fault occurs on the field winding, it is detected by the output of a voltage detector connected across the resistor or the output of the current converter, and an alarm device is operated. At the same time, another resistor is connected between the other terminal of the field winding and the current converter through a switch, and the magnitude of the ground fault is calculated by the outputs of the voltage detector and of the current converter before and after closure of the switch. When the magnitude of the ground fault is large the generator is disconnected.

Abstract: An automatic voltage regulator for an excited AC generator comprising at least one controlled rectifier for conducting the field current of the generator, a trigger signal supplying means for supplying a trigger signal to the controlled rectifier when the controlled rectifier is forward biased, a voltage detection circuit for detecting the output voltage of the generator, an inhibiting circuit for inhibiting turn-on of the controlled rectifier when the instantaneous value of the voltage detection circuit exceeds a predetermined voltage, characterized in that the voltage detection circuit comprises a phase shifting circuit receiving and shifting the phase of the output voltage of the generator. The amount of phase shift may be selected so that the inhibiting operation terminates and hence the turn-on of the controlled rectifier is effected at any angle within a wide range to adjust to the load being energized.

Abstract: Disclosed is an apparatus for carrying out normal stop of a synchronous generator in an advantageous manner without use of a field breaker. The apparatus comprises a six-phase thyristor converter for controlling field excitation of the synchronous generator in dependence upon terminal voltage thereof, which converter exhibits not only a forward conversion function (power rectifier) but also backward conversion function (power inverter). When a generator operation stop command is produced, the operation of the converter in power rectifier mode is changed over to power inverter mode.

Abstract: A generator has a stator which is provided with a multipole main winding and with an auxiliary winding, which is separate from and has the same number of poles as said main winding and a coil width not in excess of one-half of the pole pitch of said main winding. An exciter has a field-exciting winding. A controller is connected between said auxiliary winding and said field-exciting winding to energize the latter.

Abstract: An apparatus for protecting a synchronous machine from a field overvoltage is disclosed. The apparatus comprises a field excitation control circuit which is impressed with the armature voltage of the synchronous machine so as to provide a DC power supply for producing a DC output to excite the field winding of the synchronous machine, a first discharge circuit which is adapted to discharge the stored energy of the field winding when the synchronous machine is to be tripped under predetermined conditions, and a second discharge circuit for reducing the field voltage by allowing a field current to flow therethrough in response to generation of an overvoltage whose absolute value is higher than a predetermined level, across the field winding.

Abstract: A brushless three-phase current generator having a fed-back, controllable device for self-excitation and automatic control of the energizing current, said device comprising controllable means for deriving from the generator output part of the output voltage and the load current of the generator and the vectorial combination and supply thereof to a multi-phase rectifier whose output is connected to a stationary d.c. energizing winding of an excitor, the rotating multi-phase winding of which enables the rotating field winding of the generator through a commonly rotating rectifier, wherein the synchronous reactance of the multi-phase winding of the excitor at the frequency corresponding to the nominal speed is achieved, which is greater than the equivalent impedance of the generator field winding.

Abstract: A constant frequency a.c. generating system includes an alternator driven at a variable speed. A rectifier provides a d.c. supply for a rotary inverter. To maintain the voltage and frequency of the inverter output constant, the frequency is monitored and used to control the alternator field current and the voltage is monitored and used to control the inverter field current in a regulator circuit.

Abstract: A pair of diodes, which has an input terminal connected with a neutral point of a Y-connected output winding of an alternating current generator, is provided in addition to a full-wave bridge rectifier connected across a battery. A field winding of the alternating current generator is supplied with filed current from the battery or the full-wave bridge rectifier and further from the pair of diodes which are energized by the voltage appearing at the neutral point. The field current supply from the pair of diodes is not limited by a voltage regulator for controlling the output voltage of the generator, whereby a large increase of output power of the generator can be obtained.

Abstract: An automatic voltage regulating system in a brushless generator comprising a permanent magnet provided on the stator side of a main generator and constituting a field system of an exciter generator portion, an exciter generating coil provided on the rotor side of the main generator, rectifier for rectifying a voltage induced in the exciter generating coil, a field coil of the main generator excited by the output of the rectifier and provided on the rotor side, and an armature coil of the main generator provided on the stator side, and characterized in that the permanent magnet and a control coil are provided on the exciter field system, and an automatic voltage regulating portion which detects the output voltage of the main generator and supplies the control coil with a controlling current is provided so that fluctuations of the output voltage of the main generator can be absorbed by the control coil.

Abstract: An excitation system for a synchronous generator includes a conventional brushless exciter for providing base excitation for rated power output and a controlled source of direct current interconnected with the conventional brushless excitation system to supplement the base excitation. The supplementary excitation is supplied to the rotating field winding of the synchronous generator to provide forcing excitation to permit operation of the generator at power levels which exceed the generator's base power output level.

Abstract: An excitation control circuit for a brushless synchronous welding generator, in which the stator-mounted excitation winding is fed from a separate voltage source via two parallel-connected power transistors with independently adjustable base circuits, one transistor controlling the excitation current in the idling mode, the other in the welding mode. A change-over switch, responding to an electromagnet in the welding current circuit, alternatingly energizes one transistor, while blocking the other.

Abstract: In a synchronous dynamoelectric machine having a pilot exciter which energizes a brushless exciter, voltage regulation and forcing excitation are provided by a plurality of field coils which are disposed upon selected ones of a plurality of permanent magnets carried by the rotor of the pilot exciter. The field coils are connected together to constitute a field winding and are electrically connected to receive direct current excitation from the output of a rotating rectifier assembly through coupling means, such as a direct current regulator. In operation, the regulator is responsive to changes in the current flowing through the field winding of the synchronous dynamoelectric machine and provides a direct current output signal to the permanent magnet field winding to increase the magnetic field strength of the associated permanent magnets.

Abstract: An apparatus and a method for controlling the exciter current in a welding generator such that the open circuit voltage of the generator is regulated within suitable limits prior to arc start. A voltage controlled relay is connected to the generator's output and controls the inclusion of a voltage regulated biasing circuit in the base circuit of a transistor connected in series in the exciter circuit to assure that when the voltage exceeds a preset level of the voltage controlled relay, the exciter current will remain substantially constant.

Abstract: There is provided an exciter arrangement for generators comprising an internal combustion engine, a generator coupled with the internal combustion engine and driven thereby, an exciter for regulating excitation of the exciter, a detector for detecting a value responsive to a revolution number of the internal combustion engine, and a controller for controlling the exciter in response to an output of the detector.

Abstract: A power source system for vehicles includes a transistor relay and a first triac to vary the amount of DC delivered to a field winding of a generator through a second triac, whereby stable AC and DC currents can independently be obtained.

Abstract: In a power system, control signals derived from a measurement of dynamoelectric machine output voltage and current are selectively applied to an exciter to control the current in a field winding of the machine to control the machine reactive volt-amperes and output voltage.

Abstract: A leakage current detecting coil is provided in the output circuit of the armature of a generator. The output of the leakage current detecting coil is connected to a gate control circuit for a pair of thyristors constituting a full-wave rectifier circuit provided between the output of the generator and the field coil thereof. The full-wave rectifier circuit controls the exciting current of the generator and also interrupts the exciting current through turning-off the thyristors when the leakage current is detected.