Abstract: A rotary electric machine control apparatus is provided which controls energization of a rotary electric machine having a plurality of winding sets. The apparatus includes an energization control circuit that is provided for each of the winding sets and has a switching element related to switching of energization to the winding set, a driver circuit that outputs a drive signal to the switching element through a signal line connected to the switching element, and a protection element that is connected to the signal line and in parallel with the switching element. When combinations of the winding sets and electronic components including the energization control circuit provided for each of the winding sets are regarded as systems, in at least one of the systems, performance of the protection element is differentiated from that in the other system to make noise resistance different from noise resistance in the other system.

Abstract: A rotating electric machine for vehicles has a rotor, a stator having stator windings, MOS module groups as electric power converters, a rotation angle sensor that detects a rotation angle of the rotor, and a control circuit that has a rotation angle sensor abnormality determining section that determines whether abnormalities of the rotation angle sensor exist or not based on a phase voltage induced by the stator windings during the power generation.

Abstract: A control section is configured to, when it is detected that a voltage of a B-terminal of a power generator has exceeded a first predetermined voltage value, turn on all switching elements of a negative arm of a bridge circuit connected to one set of armature windings and turn off all switching elements of a positive arm, and reduce a field current flowing in a field winding. The control section is configured to thereafter turn off all the turned-on switching elements when a predetermined condition is satisfied.

Abstract: Certain embodiments are directed to devices, methods, and/or systems that use electrical machines.

Abstract: A method of controlling a motor is provided. The method may determine a speed of the motor, and engage a soft chopping routine on a first switch and a second switch of each phase if the motor speed is relatively low. The first switch may be driven by a first pulse width modulated PWM signal and the second switch being driven by a second PWM signal. The first and second PWM signals may be alternatingly configured such that at least one of the first switch and the second switch is closed at any point during the distributed soft chopping routine and both the first switch and the second switch are never simultaneously open.

Abstract: A thermal stress reduction method includes ramping an electric power generator to start an aircraft engine, for a time period associated with the aircraft engine start sequence toggling a three-level inverter switch array to a three-level pulse width modulation mode, determining if a first time interval in the three-level pulse width modulation mode exceeded a predetermined three-level pulse width modulation mode interval, in response to the first time interval exceeding the three-level pulse width modulation mode interval, toggling the three-level inverter switch array to a two-level pulse width modulation mode, determining if a second time interval in the two-level pulse width modulation mode exceeded a predetermined two-level pulse width modulation mode interval and in response to the second time interval exceeding the two-level pulse width modulation mode interval, toggling the three-level inverter switch array to the three-level pulse width modulation mode.

Abstract: A polyphasic multi-coil generator includes a driveshaft, at least first and second rotors rigidly mounted on the driveshaft so as to simultaneously synchronously rotate with rotation of the driveshaft, and at least one stator sandwiched between the first and second rotors. The stator has an aperture through which the driveshaft is rotatably journalled. A stator array on the stator has an equally circumferentially spaced-apart array of electrically conductive coils mounted to the stator in a first angular orientation about the driveshaft. The rotors and the stator lie in substantially parallel planes. The first and second rotors have, respectively, first and second rotor arrays.

Abstract: A dip in the output voltage of a motor-vehicle alternator, owing to a connecting of a load or a change in speed, is compensated with the aid of an alternator regulator which provides a control signal that has a duty factor and increases the excitation current of the motor-vehicle alternator. After the occurrence of the voltage dip, in a first step, the duty factor of the control signal is increased by a differential amount, and in a subsequent second step, the rate of correction is limited. After the occurrence of the voltage dip, parameters describing the instantaneous working point of the motor-vehicle alternator are determined, and in the first step, the differential amount is set as a function of the working point.

Abstract: A method is provided for controlling power generation. A control circuit is employed to control first and second switches of each of multiple switch groups of a drive circuit so that the first switches are kept in OFF state while the second switches are each switched between ON and OFF states at each given time point. With the second switches of the switch groups alternately switched ON/OFF, electrical power is fed to a circuit system, which includes a power storage device or an application device of loading.

Abstract: In a control apparatus for an inverter generator having a first, second and third windings wound around an alternator driven by an engine, and first, second and third inverters adapted to convert alternating current outputted from the first, second and third windings into direct current and invert the converted direct current into single-phase alternating current in a desired frequency so as to supply to the electric load, there is provided with an actuator (stepper motor) to open and close a throttle valve of the engine, and it is configured to detect output powers (effective powers) of the first, second and third inverters, to determine a target engine speed based on the detected output powers, and to control an operation of the actuator so that the engine speed converges at the determined target engine speed.

Abstract: Power generation efficiency is improved with a simple configuration. A braking device is provided with a brake rotor which rotates on a central axis, and friction portions which are in frictional contact with the brake rotor. A coil is wound around the outer peripheral portion of the brake rotor. A friction portion has the north pole of a magnet, and a friction portion has the south pole of a magnet. The braking device generates electricity by using an electromagnetic induction phenomenon and an electrostatic phenomenon that are caused by the interaction between the outer peripheral portion and the friction portion, for example, at the time of braking. As a result, the configuration can be simplified and the amount of power generation is not likely to be limited by a motor capability because there is very little need to use the motor as a generator.

Abstract: A method is provided for controlling power generation. A control circuit is employed to control first and second switches of each of multiple switch groups of a drive circuit so that the first switches are kept in OFF state while the second switches are each switched between ON and OFF states at each given time point. With the second switches of the switch groups alternately switched ON/OFF, electrical power is fed to a circuit system, which includes a power storage device or an application device of loading.

Abstract: A vehicle-use electric rotating machine includes a switching section having upper and lower arms each constituted of a switching element parallel-connected with a diode to rectify an AC voltage induced in each phase winding of the electric rotating machine, an on-timing setting section for setting an on timing of each of the switching elements, an off-timing setting section for setting an off timing of each of the switching elements such that, when a time period from when a phase voltage of the phase winding reaches a first threshold value to when the phase voltage reaches a second threshold value different from the first threshold value is referred to as a conduction period, a time period in electrical angle from when the switching element is turned off to when the conduction period ends is equal to a target electrical angle set depending on the rotational speed of the electric rotating machine.

Abstract: A rotary electric machine for a vehicle that is capable of starting synchronous rectification through switching elements after having ensured absence of a short circuit fault. The rotary electric machine includes a multi-phase armature winding, a switching element set that includes a plurality of pairs of upper-arm and lower-arm switching elements to form a bridge rectification circuit together with the armature winding, an on/off-timing setter that sets on/off-timing of each switching element, a switching element driver that drives each switching element at the on/off-timing set by the on/off-timing setter; and a synchronous control start determiner that determines timing when an energization period for the upper-arm switching element and an energization period for the lower-arm switching element occur alternately as start timing of the synchronous rectification.

Abstract: An apparatus in an example comprises a stator and a rotor. The stator comprises one or more coils. At least one coil of the one or more coils comprises one or more windings about a hollow spool. The hollow spool comprises a stator conveyor. The stator conveyer comprises a coolant that is located on an inner surface of the hollow spool. The rotor is electromagnetically coupled with the stator. The rotor comprises a plurality of permanent magnets.

Abstract: A power conditioner for circuit breaker panel and method of use. The apparatus comprises an electric motor electrically connected to distribution power lines into the breaker panel. The electric motor drives an electric generator. Electric power from the electric generator is fed into sector circuit breaker bus bars in the circuit breaker panel, which in turn power sector circuit breakers mounted to the sector circuit breaker bus bars. The circuit breaker panel may incorporate a main breaker between the distribution power lines and the sector circuit breaker bus bars. The apparatus may include a transmission between the motor and the generator. The method steps include using electric power from the distribution power line to run the electric motor, using the electric motor to drive the generator, and feeding power from the generator to the sector circuit breaker bus bars.

Abstract: A hybrid-electric vehicle including a matched reactance machine power generation system (MRMPGS). The MRMPGS comprises a permanent magnet rotor type machine having a selected back electromotive force (BEMF) voltage value and a selected machine inductance value. The BEMF voltage value is selected having a line-to-line peak voltage that is equal to a desired terminal voltage of the machine at a first machine speed. The machine inductance value is selected based upon a machine reactance value and a frequency value, which correspond to a proportional increase in the selected BEMF voltage value between the first machine speed and a second machine speed.

Abstract: A system and method is described for using a matched reactance machine power generation system (MRMPGS) to provide a constant-voltage power for an electric distribution system. The system and method include a permanent magnet rotor type machine without a field winding for excitation. This type of machine presents much better reliability, as the excitation of the machine is fixed and achieved by a permanent magnet embedded in the rotor assembly. The voltage regulation is achieved through speed and load coordination that is based on a machine reactance specially selected and calculated to achieve compensation between the external voltage variation and the internal machine voltage drop, resulting in substantial savings in electronics hardware.

Abstract: The switched reluctance machine providing soft chopping in the output current controls the voltage across the phase winding. When the current through the phase winding in the generating mode reaches a first predetermined value, the voltage across the phase winding is reversed and as a result, the current through the phase winding decreases. When the phase winding current reaches a second value, the phase winding is shorted so that the current increases due to the positive back-EMF through the phase winding until the first predetermined value is again reached, at which time the voltage across the phase winding is again reversed.

Abstract: A switched reluctance drive is supplied from a first voltage source (V1) during an idle period, in which it transfers energy to a second voltage source (V2). The machine is subsequently run at high power from the second source (V2), so that the first source (V1) does not have to supply the current required when the machine is operating at high power. The drive is able to regulate the amount of energy transferred to the second source (V2).

Abstract: In a multiple power source system of the present invention that has an inverter connected to a reactance, such as three-phase coils in a motor, a high voltage battery is connected with a low voltage battery via one transistor (Tr2) and one diode (D2) included in the inverter and one phase coil (U-phase coil) of the three-phase motor. The transistor Tr2 is turned on to make the electric current flow from the low voltage battery to the U-phase coil. The transistor Tr2 is subsequently turned off at a preset timing, so that the electric energy accumulated in the reactance, that is, the U-phase coil, flows through the diode D1 into the high voltage battery and thereby charges the high voltage battery. This arrangement enables the charging process from the low voltage battery to the high voltage battery without any complicated circuit structure for the voltage step-up. The three-phase motor may be unipolar driven with transistors connected to one side of the inverter.

Abstract: A method and apparatus for controlling AC power from the stator of an alternator in which groups of windings have various numbers of turns and various numbers of poles per winding can be connected in series to achieve optimum power generation at one RPM and in parallel to achieve optimum power generation at another RPM.

Abstract: A method of linearizing the output performance of a switched reluctance generator, comprises the steps of exciting the switched reluctance generator during a first phase of operation at a turn-on angle which need not be accurately calculated to produce the desired excitation current. Next, during a second phase of commutation, the switched reluctance generator is freewheeled when a phase current of the switched reluctance generator exceeds a first calculated current level. This freewheeling continues until the phase current of the switched reluctance generator exceeds a second calculated current level, at which point the switched reluctance generator enters the generation phase of its commutation cycle. The linearization of the performance occurs because the first and second calculated current levels are calculated as a function of energy converted per electrical cycle.

Abstract: A system for rectifying and regulating the flow of electrical power from a multi-winding alternator to a load such as a vehicle battery automatically changes the effective connection of the alternator windings to obtain maximum output power over a wide speed range of the alternator. When applied to an alternator of the type commonly used on vehicles such as snowmobiles, this system can approximately double the output current at maximum engine speed without reducing the output at minimum engine speed.

Abstract: An apparatus for supplying electric power to heating devices of a vehicle, making it possible to utilize the maximum amount of electric power generated by an alternator when a plurality of electrically heated catalysts mounted on the vehicle are to be supplied with electric power from the alternator only.

Abstract: A switched reluctance generator is controlled such that flux growth in a phase winding occurs at a faster rate during the initial part of the phase inductance cycle and at a second, slower rate during the subsequent part of the phase inductance cycle. The difference between flux growth and decay may be achieved either by applying different voltages during the two parts of the phase inductance cycle or by applying the same voltage over only part of the phase winding during the initial part of the phase inductance cycle and then applying that voltage across the phase winding thereafter. It is advantageous to make the increase in flux more rapid than its decay because minimizing the length of time that the flux is present while the phase inductance is rising will minimize the production of unwanted (motoring) torque.

Abstract: An apparatus for selectively rectifying one of a pair of output voltages associated with one of a a pair of output winding sets of a polyphase alternating current generator has a single controlled bridge rectifier selectively coupled to one of the winding sets. The bridge rectifier is selectively coupled in accordance with a predetermined rotational speed of the rotor. Transitions between the two winding sets is caused to occur at zero current conditions of the windings.

Abstract: A switched reluctance generator system, including a converter for coupling a dc voltage via a dc excitation bus to a switched reluctance generator and thereby providing excitation power thereto, has a separate generator bus for providing the output voltage of the switched reluctance generator. The generator bus is separate and distinct from the dc excitation bus such that the average output current generated by the switched reluctance generator is substantially independent of the generator output voltage. The switched reluctance generator system further includes switches for coupling each respective machine phase winding of the switched reluctance generator to the generator bus such that the generator provides power to the excitation bus when the switches are turned off and provides power to the generator bus when the switches are turned on.

Abstract: A switched reluctance generator system provides an ac output voltage through only one stage of power conversion. The system includes a converter for coupling a dc voltage via a dc excitation bus to a switched reluctance generator and thereby providing excitation power thereto, and further includes a separate ac generator bus for providing the ac output voltage. A bridge-type configuration of thyristor-type switching devices are used to couple power generated across each respective machine phase winding to the ac generator bus. During initiation of generating action and load faults, the thyristor-type switching devices are turned off such that the ac generator bus is effectively disconnected from the switched reluctance generator, allowing the excitation bus to be charged to a desired level. During normal generating operation, the thyristor-type switching devices are appropriately gated, increasing and decreasing current as needed, to provide the ac output voltage on the ac generator bus.

Abstract: A switched reluctance machine comprising a housing, a stator attached to the housing and a rotor mounted within the housing. The stator including teeth wound with electrical coils which are connected to form phase windings. The rotor comprising a series of laminates including teeth pressed onto a shaft. According to the present invention, at least one set of opposing phase wound stator teeth comprise permanent magnets.

Abstract: A switched reluctance generator system, including a converter for coupling a dc voltage via a dc excitation bus (or excitation nodes) to a switched reluctance generator and thereby providing excitation thereto, has a separate generator bus for providing the output voltage of the switched reluctance generator. The generator bus is separate and distinct from the dc excitation bus such that the average current generated by the switched reluctance generator is substantially independent of the generator output voltage. As a result, the switched reluctance generator is capable of resuming generating operation after occurrence of an overload, without requiring a relatively large power source to supply the overload, clear the fault (e.g., via a fuse) and re-excite the generator.

Abstract: A motor vehicle power supply system for supplying current to the direct voltage loads on a motor vehicle. The system has two alternating generators which are driven by the engine of the motor vehicle. The output windings of the respective generators are connected to bridge rectifiers that supply current to a common motor vehicle direct current load. Each generator has a field winding and the current supplied to a respective field winding is controlled by a respective voltage regulator. The voltage regulators cause pulses of current to be supplied to the field windings. The system has a control circuit for controlling the pulse width of the current pulses supplied to the respective field windings such that the pulse width of the current pulses supplied to one field winding are substantially equal to the pulse width of the current pulses supplied to the other field winding.

Abstract: A system for charging a battery from a generator including a rectifier regulator wherein the regulated voltage is stepped up to compensate for voltage drops in the cable connecting the rectifier regulator to the battery.

Abstract: A silicon controlled rectifier is connected between the output of each stator winding of a conventional alternator and a terminal of a lower voltage battery, and a control electrode of each silicon control rectifier is connected to a switching control circuit for switching the silicon control rectifiers to switch stator current alternatively to a lower voltage battery or to a higher voltage battery connected across the alternator stator. A voltage regulator is connected between the alternator field coil and the lower and higher voltage batteries.

Abstract: A voltage regulator for an internal combustion engine having a permanent magnet alternator and utilizing an SCR/diode bridge rectifier includes crowbar SCR overvoltage protection means. To assure that the crowbar SCR has an adequate period in which to cool off after being triggered on by an overvoltage surge, crowbar SCR operation is detected to generate a control signal to activate a timer which shuts off gate drive to the main bridge SCR's and thereby shuts down the bridge for a period of time sufficient to provide crowbar SCR recovery and cool off. In its preferred embodiment, the control signal is provided by the crowbar SCR gate to cathode voltage drop during protective operation, which signal is of relatively long duration, thus allowing the use of filters to eliminate spurious triggering of the timer by transient noise signals. Feedback from the switch means supplying gate drive to the bridge SCR's is used to provide a tapered charging characteristic.

Abstract: A high efficiency charging and regulating system charges a battery and regulates a voltage delivered to the battery. An alternator having a rotor with at least one magnet thereon and a stator in close proximity to the rotor has at least one alternator coil and at least one power coil. A regulating and charging device connects an output of the alternator coil to a system battery for delivering a regulated voltage to the system battery for charging thereof. Preferably, the charging and regulating means comprises a full wave SCR rectifier, gate inputs of which are controlled by voltage derived from the power coil.

Abstract: The electric power supply comprises an electric rotary machine intended to be driven by an engine in order to supply electrical energy to a battery and/or to various user units, and rectifier means combined with the machine for obtaining direct current. The machine is chosen in such a way that when it is driven by the engine at its idling speed, the voltage at the terminals of the machine is insufficient to ensure charging of the battery; the unit comprises means to make it possible to establish periodically a voltage surge at the terminals of the machine and a current for charging the battery.

Abstract: A 24/12 volt battery power supply for a vehicle includes two 12 volt batteries connected in series, and having first and second 24 volt terminals to the opposite ends of the batteries and a 12 volt terminal to the center common connection of the batteries. The 12 volt loads are divided into equal right and left side vehicle loads and the right side is connected across one battery and the left side is connected across the second battery. A three phase wye-connected alternator has the winding connected to a full wave three phase rectifier, the D.C. output of which is connected to the 24 volt terminals. The center common connection of the winding is connected directly to the 12 volt terminal. The system operates with balanced currents and charges on the two 12 volt batteries so long as the 12 volt loads remain balanced.

Abstract: A dual voltage motor vehicle electrical system wherein a pair of batteries are connected in series across the direct voltage output terminals of a bridge rectifier that is connected to a polyphase output winding of an alternating current generator. First and second groups of controlled rectifiers are connected between a junction of the batteries and the generator output winding. In low speed operation of the generator the groups of controlled rectifiers are alternately biased conductive. The time period of conduction of the groups of controlled rectifiers is controlled as a function of the difference in the voltages across the respective batteries. The phase voltages of the output winding are summed by a summing amplifier to provide a control signal. The system includes means responsive to the control signal for preventing simultaneous conduction of the groups of controlled rectifiers.

Abstract: A rectifying system for a magnet-type AC generator comprises a rectifier circuit including a composite bridge of a plurality of diodes and a plurality of thyristors for regulating and rectifying the output voltage of the AC generator, a first phase control circuit for applying a firing signal to the thyristors, a neutral-point diode, a neutral-point thyristor, and a second phase control circuit for controlling the phase of the neutral-point thyristor. The neutral-point thyristor is phase-controlled, and the voltage applied to a battery with an electrode thereof connected to the diodes is thereby regulated.

Abstract: A dual voltage motor vehicle electrical system wherein a pair of batteries are connected in series across the direct voltage output terminals of a bridge rectifier that is connected to the output winding of an alternating current generator. First and second groups of controlled rectifiers are connected between a junction of the batteries and the generator output winding. In low speed operation of the generator the groups of controlled rectifiers are alternately biased conductive. The time period of conduction of the groups of controlled rectifiers is controlled as a function of the difference in the voltages across the respective batteries. At a higher speed of the generator one of the two groups of controlled rectifiers is biased conductive, dependent upon the relative magnitudes of the voltages across the batteries.

Abstract: A voltage regulator is presented which is useful in controlling the recharging of the battery of a walk-behind lawn mower. The battery is used as an energizing source for cranking the piston engine of the mower. Once the engine is running it drives a small alternator whose rectified output is a low power capacity pulsating DC voltage capable of recharging the battery. To prevent overcharging of the battery, a voltage regulator module is introduced between the alternator output and the input to the battery. The voltage regulator includes a ripple smoothing capacitor shunted across the output of the alternator, a 3-terminal positive voltage regulator packaged in integrated circuit form having a voltage input terminal, a voltage output terminal and an output voltage adjustment terminal. A solid state diode placed in series between the voltage output terminal of the regulator and the positive input terminal of the battery prevents battery discharge through the regulator module when the engine is stopped.

Abstract: An automotive battery charging circuit with a generator having a field winding and a plurality of stator windings, the output of the stator windings being connected to the battery through a plurality of SCR's each having individual potentiometer control means responsive to a voltage differential of the associated stator winding and the battery voltage.

Abstract: An alternator for use in a brushless DC tachometer which produces are output voltage with a trapezoidal waveshape. The alternator includes a three phase toroidal winding on a plotless core. The windings are concentrated rather than being distributed. The rotor includes high intensity permanent magnets configured to provide uniform flux density over a large segment at least equal to a commutation increment.

Abstract: A full wave rectifier regulator for an alternator battery charging system has gate controlled rectifier connected in two separate branches of the rectifier bridge. The gates of the rectifiers are connected to the anode-cathode circuit of a third gate controlled rectifier (SCR) and are thereby selectively turned "on" and "off" by the current flow in the anode-cathode path of the SCR. A portion of the alternator output voltage triggers the SCR to its conductive mode whenever the battery voltage is between predetermined voltage levels. A protection circuit comprising an electronic switching component is connected to the gate of the SCR to shunt off any gate triggering current to hold the SCR "off". The switching component is connected to sense the battery voltage and to clamp "off" the SCR should its voltage either be lower or higher than the predetermined levels.

Abstract: An energy regulating system (21) includes a battery (25) connected to a single phase generator winding (23) through a connecting circuit (24) providing a full wave bridge rectifier (26) having a pair of controlled rectifiers (69, 71) which are selectively gated into connection in response to the sensed phase angle of the energy in the winding (23). A control (54) operates in response to a charge sensor (31) which senses the charge on the battery (25) and a phase sensor (79) which senses the energy phase at the winding (23) to operate a switch (44) to modify the operation of the bridge circuit (26) to interrupt the energy flow to the battery (25). An excessive energy sensor (80) responds to excessive sensed energy at the connecting circuit (24) to turn on a pair of controlled rectifiers (53, 70) to deactivate the bridge circuit (26) to prevent damage to the connecting circuit (24).

Abstract: A protection system is described for series regulators exposed to power sources such as permanent magnet alternators which may exhibit high open circuit voltages. The subject system includes a circuit which protects the control transistor in the regulator from a forward bias second breakdown by clamping it OFF responsive to the alternator output voltage exceeding a predetermined level. In one embodiment the clamping circuit keeps this transistor off during enough of the duty cycle to reduce the voltage across the control transistor to a level above which second breakdown occurs. In one embodiment, an auxiliary circuit shorts the alternator output terminals to ground to protect electrical apparatus connected to the alternator from burn-out due to high voltages occasioned by sulfated batteries or loose battery terminals which result in a high impedance being presented to the alternator.

Abstract: A tachometer generator comprising a generator section for producing rectangular polyphase alternating voltages having a peak value which is proportional to the speed of the rotor, and a commutator section including contactless change-over switches for successively transferring the alternating voltages from the generator section, and sensors for producing switching signals which actuate the change-over switches in accordance with the rotational position of the rotor of the generator section. In the commutator section the sensors are equivalent in number to the change-over switches and comprise Hall devices arrayed about a rotary shaft which is coupled to the generator section. The alternating voltages which are obtained successively from the coils of the generator section as the rotary shaft rotates, are transferred in order by the change-over switches to produce a speed signal, in analog form; which is proportional to the rotating speed of the rotor.

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 half-wave regulator rectifier utilizes a silicon controlled rectifier (SCR) as the rectifying element between an alternator producing positive and negative voltage phases or waveforms and a battery charged by the alternator. The SCR is permitted to conduct charging currents through the battery during the positive voltage phases by means of a control circuit having a transistor connected to the control gate of the SCR. The control circuit monitors the alternator voltage and causes the transistor to inhibit conduction through the SCR above a regulated battery voltage unless charging current flows through the battery before the regulated battery voltage is reached by the alternator voltage. The regulator rectifier is protected against damage when abnormal conditions exist, such as no battery connection with the regulated system.