Abstract: A connection control device for controlling the connection of a small generator unit, which is installed at the consumer's location, to an electric power system. The connection control device detects variations in frequency components which result from interruptions in the distribution of electric power to the consumer from the electric power system. When a significant variation in a frequency component is present, the connection control device disconnects the consumer from the electric power system in order to prevent injury to line workers.

Abstract: A saturable reactor diode snubber assembly is provided for use witha brushless excitation system. The diode snubber provided includes a thin film member composed of a saturable magnetic material. The magnetic material is saturated for a large percentage of the current cycle of each pase of the ac exciter. When the current approaches zero and the diode approaches reverse recovery, the magnetic film member of the present invention comes out of saturation and turns linear increasing overall exciter inductance and decreasing current fall rate, thereby reducing reverse recovery peak current and diode stored energy. This in turn reduces the effects of voltage spikes normally experienced during diode reverse recovery. The magnetic material is used at a predetermined thickness such that a desired result is obtainable. One embodiment of the invention involves placing the magnetic material on the side of the armature slot wedge adjacent to the top coil.

Abstract: A vehicle AC generator control device includes an AC generator including a field coil; a rectifier for rectifying an AC output of the AC generator; a battery connected to an output terminal of the rectifier; a voltage regulator including a switching element series-connected to the field coil, the voltage regulator detecting a terminal voltage of the rectifier or battery to operate the switching element to control a field current of the field coil to adjust an output voltage of the generator to a predetermined value; a dummy load unit including a dummy load balanced with an output capacity of the AC generator; and an overvoltage limiter which detects when the output voltage of the AC generator exceeds a set value, to energize the dummy load unit, so that the dummy load unit is connected to an output terminal of the rectifier, to thereby suppress any abnormal rise of the output voltage.

Abstract: A polyphase full-wave rectifying circuit that is connected to a polyphase AC line having a neutral point includes DC output terminals and plural pairs of rectifying elements. Each pair is composed of two rectifying elements in series and these pairs are connected in parallel with each other between the DC output terminals. One of the pairs of rectifying elements is a pair of Zener type rectifying elements and the interconnection point of this pair is to the neutral point of the polyphase AC line. The other pairs are pairs of ordinary type rectifying elements, each interconnection point of these pairs is to each phase point of the polyphase AC line. Both internal surges and external surges are absorbed through the pair of Zener type elements. Therefore, the clamping voltages of the internal and external surges results in the same level, being twice as high as the Zener voltage. The peak voltage applied to one Zener type element reduces by half the surge peak voltage.

Abstract: A permanent magnet generator system is provided with a permanent magnet generator having a multiple phase armature that includes several circuit branches which are electrically connected to provide a multiple phase output voltage to the output terminals of the generator. At least two of the circuit branches include an armature phase winding and a switching device electrically connected in series with the winding. The switching devices are opened and closed in response to a control signal to disconnect the generator from the remainder of the electrical system and to simultaneously de-energize the individual phase windings of the generator armature to protect against a fault occurring within the generator housing.

Abstract: A control device for a vehicle a.c. generator comprises a rectifier connected to an armature coil of the a.c. generator, and having a main rectification output terminal for outputting the rectified output to a battery, and an auxiliary rectification terminal connected to one end of the field coil of the generator; a voltage regulator which turns on and off the field current by means of a switching element connected to the other end of the field coil to adjust the output voltage from the generator at a predetermined level; an overvoltage limiting unit including a switching element which conducts when the output voltage from the generator exceeds a predetermined overvoltage value; and a switching unit which is energized by the conduction of the switching element in the overvoltage limiting unit to ground the auxiliary rectification terminal of the rectifier.

Abstract: A system for detecting load has a first detector for detecting load on a generator based on the voltage in a circuit of an armature of the generator, and a second detector for detecting the load on the generator based on the voltage in a circuit inductively coupled to the armature circuit. An output of the first detector is compared with a first reference value by a first comparator and a first overload signal is produced when exceeding the first reference value. A second comparator is provided for producing a second overload signal when exceeding a second reference value. In response to the first and second overload signals alarm lamps are turned on for providing an alarm of the overload.

Abstract: There is disclosed a power regulating system for portable engine generator wherein overcurrent protection is provided by connecting the AC output of an AC generator driven by an engine to a rectifier for conversion to a DC current, supplying the DC current so obtained to an inverter to obtain an AC current of an arbitrary frequency, and providing for stopping of the driving signal to the inverter when an overcurrent state is detected in the inverter.

Abstract: A voltage regulator circuit for an AC generator is disclosed which comprises a holding circuit for holding the power transistor, which is coupled in series with the field winding of the generator, in the non-conductive state after the Zener diode of the voltage detecting circuit is turned off, and a releasing circuit for releasing the holding action of the holding circuit periodically at a predetermined interval. The holding circuit includes a pair of transistors turned on and off in phase and in antiphase with the power transistor, respectively, the transistor in antiphase, when conductive, holding the power transistor in the non-conductive state. The releasing circuit, on the other hand, includes a pulse generator for generating trigger pulses periodically at a predetermined interval, and a transistor which is turned on by these trigger pulses to turn off the transistor in antiphase holding the power transistor in the non-conductive state. The interruption frequency of the excitation current, i.e.

Abstract: An alternator regulator includes a status sensor connected to monitoring the connection of a voltage sensor to the alternator and a separate current limited monitor unit to regulate the output in accordance with the alternator current output. The sensor monitor unit includes a continuity circuit detector coupled to the voltage sensor and operable to continuously monitor the state of the connection to the alternator. A fault in the circuit connection such as a loose terminal, a broken lead or other such faults, opens the continuity circuit and generates a signal which drive the regulator off and terminates operation of the alternator, thereby protecting the alternator from possible destruction. A voltage/current mode selector receives a voltage related signal and a current related signal. A signal comparator is coupled to the voltage related signal and the sensed current related signal and generates a logic control signal applied to the selector to transmit one of the two signals.

Abstract: The present invention relates to a control system for an engine driven generator, and more specifically, to a control system for controlling the field current to the field coil of the generator to prevent a rapid decrease in the engine rotational speed throughout a transient period when an electric load, such as a head light or an air conditioner, is switched on and begins to draw current.In one embodiment of the invention, the control system comprises digital control means for repeatedly alternating throughout the transient period between calculating an on period and switching the field current on for the on period, and then calculating an off period and switching the field current off for the off period. The digital control means also detects a high output torque operating condition of the engine, and when such a condition is present, switches the field current on throughout the entire transient period.

Abstract: A permanent magnet generator and rectifier is connected to the exciter of an alternator and a separate rectifier provides a D.C. voltage supply to a voltage regulator. A thyristor is connected in series with a second fuse across the exciter rectifier to short circuit the supply in series with a main external fuse. If the main fuse fails to open, the second fuse opens. The second fuse is potted in the regulators to prevent tampering. An overexcitation and a low voltage demand signal are sensed. The two signals are coupled to a NAND logic gate to produce an output shut-down signal. If either even is established and the first produces a signal, a shut-down signal is generated to a second comparator amplifier of latch circuit. A delay circuit connects the shut-down signal to a triggered oscillator for firing the thyristor.

Abstract: A protection circuit for use in a vehicle mounted generator 1 equipped with a voltage regulator 3 having an output transistor circuit 306 connected to a field winding 102 of the generator and an overvoltage alarm device 4 having an overvoltage detector, comprises diodes 410, 411 for selectively connecting an output of the overvoltage detector to the output transistor circuit so that the transistor circuit is turned off only when an overvoltage caused by the generator which becomes out of control of the voltage regulator due to disconnection of a generator output to a battery to be charged thereby and/or of the battery to the voltage regulator is detected to terminate a power supply to the field winding until the output voltage of the generator reduces to a preset level.

Abstract: A voltage regulator includes an output power element and protection circuit connected to a control terminal of the power element in such a way as to cause the element to conduct in a direction opposite to that of normal operation, when the transient overvoltages of polarity opposite to that of the generator reach a predetermined value. The energy associated with the transient is thus discharged via the output power device and it is not therefore necessary to use additional power components to carry out this function, leading to reductions in size and production costs.

Abstract: Transfer apparatus for use with an AC generator having a field winding, the DC energization of which controls the output of the generator. Associated with the generator are first and second voltage regulators each including means for sensing the output of the generator and means for varying the DC energization of the generator field winding to regulate the output of the generator to a respective reference level for each voltage regulator. The transfer apparatus includes a circuit for generating a first signal as a function of the generator output as sensed by the first voltage regulator sensing means and a second signal as a function of the generator output as sensed by the second voltage regulator sensing means. Another circuit independently produces an additional signal to which the first and second signals ordinarily have a predetermined relationship. A further circuit selects the first or second voltage regulator to energize the generator field winding.

Abstract: A battery voltage regulator for a vehicle charging system includes a voltage control circuit for controlling a battery terminal voltage and an external terminal connected to the positive terminal of a battery through the series combination of a charge lamp and an ignition switch. The regulator is at least composed of a charge lamp drive circuit responsive to a generation output of an alternator in order to energize the charge lamp, a power supply circuit responsive to the potential at the above mentioned external terminal to supply operational power to the voltage control circuit, and a malfunction-preventing circuit connected between the above mentioned external terminal and ground. The malfunction-preventing circuit prevents the power supply circuit from operating by disturbances such as leakage current flowing into the regulator through the external terminal.

Abstract: Three possible types of "faults" may be detected in the ignition system of a vehicle, using simple combinational logic to provide an essentially error-free activation of an indicator when a true fault is present. "Fault" signals which mean non-rotation of the alternator, broken cables or short circuits and the like are distinguished from transient and less significant conditions. The latter conditions are prevented from activating the indicator. A single indicator lamp serves to alert the user to a serious fault requiring service.

Abstract: An electronic circuit is disclosed for detecting a non-operating or fault condition in an alternator. The disclosed embodiment senses the alternator's unrectified output voltage and generates a control signal when the alternator's output voltage fails to exceed a threshold. That threshold is selected to be outside the range of any static voltage the alternator might generate as a result of leakage currents therein. Further circuitry preferably responds to the control signal by generating an indication of a non-operating condition in the alternator.

Abstract: The present invention provides a device for regulating an ac current circuit using a magnetic relay which is suitable for use in an incandescent lamp circuit or electric motor circuit to eliminate or reduce inrush-current. The present device comprises connecting power switch, diodes, series resistance and relay such that, after closing the power switch, an ac current first flows to a load through the series resistance for a brief time, then to the load through the contacts of the relay after a lapse of the brief time by bypassing the series resistance.

Abstract: A circuit for detecting the occurrence of a shorted diode in the rotating rectifier of a brushless alternator. A comparator has connected to it signals representing the base drive to the voltage regulator output transistor and the voltage at the terminal of the generator field winding connected with the collector-emitter circuit of the output transistor. The occurrence of a field winding terminal voltage of the order of the voltage at the anode of the diode which shunts the voltage regulator output transistor, in the absence of a drive signal to the transistor, indicates that there is a shorted rectifier diode.

Abstract: A power supply system for feeding low cold resistance incandescent lamps from a diode-rectified alternating current generator where the system does not have a battery or other voltage source for energizing the lamps. A control circuit is connected between the generator and lamps that includes a resistor that can be bypassed by the closure of relay contacts. The control circuit energizes the lamps such that generator voltage does not collapse when the relay contacts close. The resistor can have a negative temperature coefficient of resistance.

Abstract: A supervisory unit for detecting abnormalities in shaft voltage of rotary electrical machinery and apparatus such as brushless synchronous machines. The supervisory unit includes a first detector for detecting the voltage across at least two points of the rotor shaft, a second detector for detecting the voltage between the rotor shaft and ground, and a third detector for detecting an electrical condition of an AC exciter which constitutes part of the field system of the apparatus. The third detector may detect electrical signals indicative of the field system voltage or the field system current. The supervisory unit includes a voltage comparator and a frequency comparator which receive detection signals from the three detectors to provide a signal indicating abnormality when an abnormal condition occurs, such as contact failure of a grounding brush or a failure in coil insulation.

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 transient over-voltage suppressor circuit for a motor vehicle power supply system that includes a diode-rectified alternating current generator. The suppressor circuit comprises a dual coil relay, a Zener diode and a small resistor having a positive temperature coefficient of resistance. The Zener diode and relay coils are connected across the output terminals of a bridge rectifier connected to the generator and when a transient over-voltage occurs the contacts of the relay are closed. When the relay contacts close they connect the resistor and one of the relay coils across the output terminals of the bridge rectifier. The relay contacts open when the resistance of the resistor increases to a predetermined value.

Abstract: An electric power generator which includes a component, for example, a Zener diode, connected in series with the usual return diode which is connected in parallel to the excitation winding of the alternator. The Zener diode makes it possible to set the discharging voltage due to the energy stored in the magnetic field associated with the inductance of the excitation winding at a relatively high level during high-voltage transients caused by the accidental disconnection of the wire connecting the alternator to a load or a terminal of the motor vehicle battery while it is in the charging stage. The result is a more rapid dissipation of the energy stored in the excitation circuit, and therefore results in an output transient having a reduced energy content. Thus, it is possible to construct a voltage regulator and such other devices as may be powered by the alternator in the form of low-voltage integrated circuits.

Abstract: High noise immunity instrumentation for monitoring brush arcing in a dynamoelectric machine is disclosed. In a preferred form the instrumentation includes a stabilized variable threshold discriminator operative in conjunction with a feedback network and a non-linear high frequency amplifier to provide a discriminator threshold which increases with increasing levels of background noise so that only the arc indicative portions of the signal are passed. A substantial increase in the signal to noise ratio is obtained. The feedback network includes a relatively long time constant integrator and buffer amplifier. Further, to provide an alarm upon the occurrence of brush arcing, an alarm network is provided which includes a comparator for continuously comparing the arc indicative signal with a reference signal which is automatically adjusted to compensate for changes in the average level of the signal from the non-linear high frequency amplifier.

Abstract: A generator system which is self-excited even during a fault condition includes a main generator having armature windings and a main field winding which is excited by a rotary transformer. The rotary transformer includes a stationary primary winding and a rotating secondary winding, with the primary winding receiving a controlled portion of the main generator armature output. The current through the primary winding of the transformer is controlled by silicon controlled rectifiers which are gated by a voltage regulator circuit. The voltage regulator circuit in turn receives signals from the voltage delivered to the load, the highest phase current delivered to the load and the voltage at the main generator armature output. The voltage regulator controls the current through the primary winding of the transformer in accordance with the voltage delivered to the load if that voltage is greater than a predetermined value.

Abstract: An output transistor is serially connected to a field coil in a battery charging AC generator to break and make a field current through it under the control of a control transistor to adjust a rectified voltage from the generator to a predetermined magnitude. Another transistor is connected to the output transistor to respond to a collector-to-emitter voltage of the latter in excess of a predetermined magnitude as sensed by it to turn the output transistor off.

Abstract: An in situ self-diagnostic automotive alternator battery charging system is disclosed. Included are: a battery; voltage regulator sensing battery voltage and generating an excitation signal; and an alternator driven by a vehicle engine provide a rectified electrical signal to charge the battery in response to the excitation signal. Electronic circuit status detectors, variously coupled to the battery, voltage regulator and alternator, maintain a first logic state when a corresponding signal characteristic is within a predetermined range and a second logic state when the corresponding characteristic is outside the predetermined range. Combinatorial logic means respond to a logic state sequence from the detectors to identify predetermined sequences of the logic states resulting in the identification of faults in the charging system.

Abstract: There is disclosed a system for predicting desynchronization of a synchronous machine by detecting a phenomenon of radical variation of the magnetic flux in the gap of a synchronous machine immediately before falling in an asynchronous state. For example, a functional value of the fundamental harmonic component and that of the higher harmonic component of the flux in the gap are detected for comparing the variation of each functional value with a predetermined reference level to predict desynchronization of the synchronous machine.

Abstract: A power generation control system for a vehicle generator comprises a generator including an armature coil, an exciting coil and a rectifier for rectifying the AC output of the armature coil, a battery, and a voltage control device for controlling the activation of the generator in accordance with the terminal voltage of the battery. This power generation control system further comprises an abnormal voltage detector circuit for detecting the voltage generated across the armature coil and cutting off the current flowing in the exciting coil when said voltage exceeds a predetermined value. The abnormal voltage detector circuit has the function to hold this forcible stoppage of power generation.

Abstract: A detector monitoring the voltage ripple in the rectified electrical output signal of an alternator in a multiphase alternator battery charging system is disclosed. A circuit monitors the undulating alternator output signal and produces a signal level in response. To correct the detector operation for various magnetic phenomena present in the alternator, a first circuit measures the rotational speed of the rotor and produces a proportional signal. A second circuit determines the excitation current supplied to the field coil. The measurement and determination are separately weighted and combined to form a corrected comparison threshold value. A variable threshold circuit combines the signal proportional to the rotational speed of the rotor and the determined field coil excitation current to produce a combined signal level.

Abstract: The excitation winding of an alternator is energized through a silicon controlled rectifier (SCR) from the output of the alternator. The SCR is bypassed by a constant current network to allow the alternator to start up; even with no excitation current, when the alternator output voltage is due to residual magnetism alone, this network can pass a current into the excitation winding, and build the current up gradually to a value above the latching current of the SCR. When this has happened, the SCR can latch on after being fired, and takes over control of the excitation current. Because the network is a constant-current network rather than a purely resistive network, it can be designed to pass sufficient current at low alternator output voltages, without having to dissipate excessive power at higher output voltages. Also, when the output voltage is at its normal operating value, the constant-current network is rendered non-conductive, to avoid the excessive power dissipation which might occur at full voltage.

Abstract: The excitation winding of an alternator is energized through a silicon controlled rectifier (SCR) from the output of the alternator. The SCR is bypassed by a constant current network to allow the alternator to start up; even with no excitation current, when the alternator output voltage is due to residual magnetism alone, this network can pass a current into the excitation winding, and build the current up gradually to a value above the latching current of the SCR. When this has happened, the SCR can latch on after being fired, and takes over control of the excitation current. Because the network is a constant-current network rather than a purely resistive network, it can be designed to pass sufficient current at low alternator output voltages, without having to dissipate excessive power at higher output voltages. Also, when the output voltage is at its normal operating value, the constant-current network is rendered non-conductive, to avoid the excessive power dissipation which might occur at full voltage.

Abstract: In a voltage control apparatus for an electric generator (1) for vehicles including an armature winding (3), an exciting coil (4), a rectifier (2) for rectifying an a.c. output from the armature winding, and a voltage regulator (5), the voltage regulator comprises a differential amplifier circuit (26) producing a detected voltage corresponding to a difference between a battery charging voltage and a reference voltage, a comparator circuit (30) comparing the detected voltage with a triangular waveform voltage generated at constant periods and producing a pulsed output voltage, a first driver circuit (51) effecting duty-factor-control of an exciting current flowing through the exciting coil in response to the pulsed output voltage, and an initial excitation circuit (32) for causing a predetermined small initial exciting current to flow through the exciting coil intermittently during a time interval after the start of the electric generator.

Abstract: An electronic sensing circuit monitoring the voltage on each of two alternating current power lines indicates when a load may be transferred from one of the power lines to the other without generating undesirable transient voltages or currents in the load.

Abstract: A protective circuit is provided for a brushless excitation system using a rotating rectifier assembly to supply field excitation to a synchronous generator. A thyristor is connected across the generator field winding and made conductive when the field winding voltage exceeds a preset level to shunt the field winding and protect the rectifier diodes against high reverse voltages.

Abstract: An adjustable speed propulsion engine for a boat also drives an electric generator which supplies electric power to an electric load circuit on the boat. A solid state electronic control circuit senses when generator voltage departs from a voltage "window" or range defined by preselected low and high voltages (as a result of a departure in engine speed from a cruise speed range to some lower or high speed) and operates a contactor to disconnect the generator from the load circuit to prevent low or high voltage damage to electrical equipment on board. The electronic control circuit operates the contactor to reconnect the generator to the load circuit only when generator voltage rises to a preselected initial turn-on voltage which is above the preselected low voltage but below the normal rated voltage of the generator. The electronic control circuit includes time delay means to prevent a transient low voltage condition ("flicker") from causing disconnection of the generator from the load circuit.

Abstract: A generator operation indicating apparatus for vehicle generators having a protective circuit against abnormal voltage, includes a drive circuit for turning an indicating device on from the time of closing of a key switch until the time that a vehicle generator attains a predetermined operating condition to indicate the generator operation and a control circuit for forcibly rendering the drive circuit inoperative in response to the occurrence of an abnormal voltage between the indicating device and the drive circuit. When the generator attains the predetermined operating condition, the indicating device is turned off and the supply of current to a load circuit is started. In this case, the drive circuit is also forced to come out of operation upon occurrance of an abnormal supply voltage.

Abstract: In a synchronous generator-motor, having both its main armature windings and exciter winding located on the stator and both the main field winding and the exciter armature windings including a rectifier for providing DC current to the main field located on the rotor and also including a voltage regulator responsive to the main armature voltage for regulating the current applied to the exciter field; the effects of transient currents in the main field windings resulting from load removal during the generator mode of operation and the voltages induced during motor start-up are substantially reduced by utilizing a resistive circuit operatively controlled by a transistor switching network that is in turn responsive to the exciter voltage and the induced voltage in the main field windings.

Abstract: A generator set includes a main generator, a permanent magnet pilot alternator, a rectifier assembly connecting the pilot alternator output to first and second supply rails, a relay having a contact, and a regulator for the main generator having a semi-conductor output element, the output element, the field winding and the contact being connected in series between the first and second supply rails. A power supply circuit is transformer coupled to the pilot alternator and provides a stabilized power supply both for the regulator and the relay, such power supply circuit having an earthed terminal. A resistor is connected between the second supply rail and the earth terminal, so as to limit fault current in the event of an earth fault in the connection between the contact and the field winding.

Abstract: A thermoelectric generator is equipped with a protective device which upon overload conditions disconnects a primary load, such as a rechargeable battery, in order to protect the secondary load, i.e., the burner, fuel pump and other ancillary items necessary to operate the thermoelectric generator. The protective device includes a voltage selectable breakdown diode, a transistor switch, a relay whose coil is connected to the transistor switch and preferably an anti-clatter circuit.

Abstract: In a brushless synchronous generator with an exciter, in which the three phase armature winding of the generator is coupled through a series regulator to the field winding of the exciter, and in which the rotating armature of the exciter feeds the rotating field winding for the synchronous generator through rectifiers, the series regulator being coupled in series between the three phase windings of the generator and the field winding of the exciter and including a control element, and in which there is a bypass diode across the exciter field winding, in order to protect the control element, a protective device is disposed between the control element and the three phase winding and an overvoltage arrester is placed in parallel across the exciter field winding and the bypass diode, the overvoltage arrester operating if an overvoltage occurs, thereby causing increased current to be drawn to actuate the protective device in series with the control element thereby preventing the synchronous generator from reaching

Abstract: Apparatus for generating minimally delayed closing instructions for turbine valves of turbo-generator sets in the event of power system short circuits wherein major faults resulting in a drop in the system voltage are detected and act upon the valve means controlling the fluid flow to the turbine in such manner that a rapid closure of the valve means prevents the turbo-generator from falling out of step in the case of a sustained fault condition. A provisional valve-closing signal is produced upon a predetermined drop in the system voltage but this is cancelled in the event that the ensuing acceleration of the turbo-generator set does not increase to a predetermined level within two revolutions of the set.

Abstract: In a system for limiting torque occurring in a turbine-generator shaft when a three-pole short circuit is switched off, one pole of a switch that switches-off the short circuit is opened first, and both of the other poles are then opened after the passage of a predetermined delay period.