Abstract: A motor controller that is operable to control a motor includes drive current generation circuitry having an output coupled to the motor. The motor controller further includes a velocity control path. The velocity control path includes angular velocity estimation circuitry having an input adapted to be coupled to the motor, a velocity comparator having first input coupled to a target velocity input and a second input coupled to an output of the angular velocity estimation circuitry, and an adaptive velocity controller having a first input coupled to an output of the velocity comparator and having an output coupled to a first input of the drive current generation circuitry. The motor controller further includes controller parameter determination circuitry having a first input coupled to the output of the angular velocity estimation circuitry and having an output coupled to a second input of the adaptive velocity controller.

Abstract: According to some embodiments, an apparatus comprises a multi-level power converter configured to convert an input voltage to an output voltage, wherein the multi-level power converter comprises one or more switching groups, wherein a switching group of the one or more switching groups comprises a pair of switches and a flying capacitor, and a controller configured to determine a duty reference for the switching group, determine a duty correction factor for the switching group based upon a flying capacitor voltage error of the flying capacitor, determine a sign correction signal based on a flying capacitor ripple voltage, and determine a duty command for activating the pair of switches based on the duty reference, the duty correction factor, and the sign correction signal.

Abstract: According to some embodiments, a method for controlling a motor comprises generating a stall threshold based on a torque generating current parameter associated with the motor. A motor stall condition is identified based on a torque generating voltage parameter associated with the motor violating the stall threshold. Operation of the motor is adjusted responsive to identifying the motor stall condition.

Abstract: Provided is a transformer arrangement wherein active and/or reactive power can be injected in an alternating current link using a current regulator and a voltage regulator portion, wherein at least one winding with which the current regulator is connected in parallel is at least one tertiary winding, and wherein the current regulator includes a number of current regulator sections, each connected to a corresponding voltage regular section of a voltage regulator portion via a corresponding dc link.

Abstract: The present disclosure relates to a voltage regulation circuit (100).

Abstract: Embodiments of the present disclosure can include a hybrid transformer system comprising an electrical voltage transformer comprising: a high-voltage winding, the high-voltage winding comprising a first end and a second end, the first end having a lower voltage than the second end; a plurality of taps disposed proximate the first end of the high-voltage winding; a multi-level converter coupleable to the plurality of taps of the electrical voltage transformer, the multi-level converter configured to simultaneously control voltage injection and VAR injection to the high-voltage winding of the electrical voltage transformer; and a controller electrically coupleable to the multi-level converter, such that when the multi-level converter is coupled to the plurality of taps of the electrical voltage transformer, the controller is configured to selectively inject at least one of VARs or voltage to the high-voltage winding of the electrical voltage transformer.

Abstract: Embodiments described herein are directed to power switching circuits having a saturable inductor. In one embodiment, a power switching circuit includes a power switch assembly operable to be connected to a power source. The power switch assembly includes a plurality of parallel power switches connected to and receiving current from the power source and a saturable inductor electrically coupled in series with the plurality of parallel power switches.

Abstract: A network node for a substation or a local network station has a control transformer with a primary side and a secondary side, an input line connected to the primary side, and an output line connected to the secondary side. A protective switch is provided in the input line or in the output line, and a sensor detects an electrical parameter in the input line or in the output line and generate a measurement signal. A controller coupled to the control transformer, to the protective switch, and to the sensor, serves to operate the control transformer in dependence on the measurement signal such that the control transformer has a predetermined transmission ratio and open the protective switch in dependence on the measurement signal as soon as the control transformer has the predetermined transmission ratio.

Abstract: An illumination system includes a master power supply providing power to several illumination modules. The master power supply is constructed and arranged to generate high-frequency and low-voltage electrical power provided to a primary wire forming a current loop. Each illumination module includes an electromagnetic coupling element and several light sources.

Abstract: A method of using an umbilical between a surface location and an underwater location of an underwater fluid extraction well system is provided. The umbilical includes an electrical power conductor configured to transmit electrical power at a first frequency from a source at the surface location to the underwater location. The method comprises detecting that the umbilical has been compromised by the ingress of water. In response thereto, the method comprises converting electrical power from the source to electrical power at a second frequency, wherein the second frequency is lower than the first frequency or DC electrical power; transmitting the electrical power at the second frequency or DC electrical power to the underwater location via the conductor; and converting, at the underwater location, the electrical power at the second frequency or DC electrical power to electrical power at a frequency used by the underwater equipment of the well system.

Abstract: An electronic device includes a chargeable battery, a system section, and a charging control section. The charging control system allocates electrical current supplied from the external device to the system section for use thereby and the battery for charging. The charging control section stops charging of the battery temporarily when a prescribed condition is met in the system section and the electrical current supplied via the cable is not a maximum current for the cable, and regulates the electrical current supplied via the cable to be at a constant level below the maximum current. The charging control section supplies electrical current from the battery to the system section as needed to meet a power demand by the system section that is not met by the electric current via the cable, while the electrical current supplied via the cable is being regulated to be at the constant level.

Abstract: A method of controlling a voltage regulator having a nominal input and a nominal output structured to operate in a forward power mode wherein power flows from the input to the output and a reverse power mode wherein power flows from the output to the input. The method includes sensing current flowing through the voltage regulator, determining a direction of power flow through the voltage regulator based on the sensed current, determining a verified direction of power flow through the voltage regulator by altering a voltage between the input and the output and analyzing an effect caused thereby on at least one of a voltage at the input and a voltage at the output, and selecting a voltage regulating scheme for controlling the voltage regulator based on the verified direction of power flow.

Abstract: An illumination system includes a master power supply providing power to several illumination modules. The master power supply is constructed and arranged to generate high-frequency and low-voltage electrical power provided to a primary wire forming a current loop. Each illumination module includes an electromagnetic coupling element and several light sources.

Abstract: A bidirectional AC series voltage regulator that regulates an output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power. The AC series voltage regulator detects the power inductor current direction data signal and can generate power inductor current direction data signals for its control to determine the AC input voltage polarity at all time; wherein the determination of the AC input voltage polarity is unambiguous during the AC input voltage zero crossover and near zero points; and wherein the determination of the AC input voltage polarity allows normal switching sequence of the AC bidirectional switches during the AC input voltage zero crossover and near zero points to prevent power “shoot-through.

Abstract: The present disclosure provides a management device for a charging circuit and a wireless terminal, which belong to the technical field of management control of a linear charging circuit. The device includes a power supply management module (5), a buck switching voltage converter (1) and a linear charging circuit (2). The power supply management module (5) includes an adjustable Low Dropout (LDO) linear regulator (6) and an Analog-to-Digital Converter (ADC) (4), wherein the output terminal of the adjustable LDO linear regulator (6) is connected with the feedback terminal of the buck switching voltage converter (1) through a first preset resistor (R62). The input terminal of the ADC (4) is connected with the anode of a battery (3). The control terminal of the power supply management module (5) is connected with the control terminal of the linear charging circuit (2). The output terminal of the buck switching voltage converter (1) is connected with the input terminal of the linear charging circuit (2).

Abstract: A negative capacitance is developed by configuring an inductor as two inversely or opposingly coupled windings having different numbers of turns and connecting a capacitance to a center tap between the two windings. The negative capacitance is developed on the side of the inductor having the winding with the greater number of turns.

Abstract: A power converter (1) comprises a voltage level increasing circuit (3) which receives a DC-input voltage (VIN) between first and second power converter inputs (IN1, IN2), and which has an output (O1; O2, O3) to supply an adapted input voltage having either a higher level than the input voltage (VIN) or a polarity opposite to the input voltage (VIN). A down-converter (2) has first and second down-converter inputs (IN3, IN4), a control switch (S1) with a main current path arranged between a first node (N1) and the first downconverter input (IN3), an inductor (L) arranged between the first node (N1) and a load (LO), and a sync switch (S2) arranged between the first node (N1) and the second down-converter input (IN4). A controller (4) controls the control switch (S1), and switches (S3, S4; S3, S4, S5, S6, S7, S8) of the voltage level increasing circuit (3) for either coupling the input voltage (VIN) or the adapted input voltage to the first node (N1) or to the first or second downconverter inputs (IN3, IN4).

Abstract: In some embodiments, a regulator with a reverse coupled inductor is provided. It can operate in both a multi-phase and a phase shed mode. When in the phase shed mode, it has circuitry to provide a low resistance path for induced current.

Abstract: A wireless communication terminal includes first and second case members coupled together by a coupling portion so that the positional relation therebetween can be changed, an external wireless communication antenna provided at the first case member, an external wireless communication control portion mainly controlling external wireless communication carried out through the external wireless communication antenna, a first internal wireless communication antenna, a first internal wireless communication control portion controlling internal wireless communication carried out through the first internal wireless communication antenna, a display part provided at the second case member, a second internal wireless communication antenna, a second internal wireless communication control portion controlling internal wireless communication carried out through the second internal wireless communication antenna, and an output power control portion controlling the output power of waves transmitted by the internal wireless c

Abstract: A control apparatus for a power conversion circuit and a control method thereof are provided. The method of the control apparatus includes producing a first control signal and a second control signal; modulating the first control signal according to an output voltage of the power conversion circuit; detecting the output voltage of the power conversion circuit to attain a detecting result; if the detecting result exhibits the input voltage of the power conversion circuit below a normal operating level, using the second control signal to control the power conversion circuit; or if the detecting result exhibits the input voltage of the power conversion circuit above the normal operating level, using the first control signal to control the power conversion circuit. The duty cycle of the fist control signal is greater than that of the second control signal.

Abstract: A drive system for a motor having a rotor and a phase winding (a, b, c) comprises; a drive circuit including switch means associated with the winding a, b, c for varying the current passing through the winding; rotor position sensing means arranged to sense the position of the rotor; control means arranged to provide drive signals to control the switch means; a power input for connection to a power supply at a nominal voltage; and boost means in electric communication with the power input and power output, and controllable to boost the nominal voltage to a higher voltage for application to the winding.

Abstract: A semiconductor device structure includes a semiconductor substrate, a resistor layer, and a capacitor layer. The resistor layer is configured to overlie the semiconductor substrate. The resistor layer has a resistor disposed therewithin. The capacitor layer is configured to overlie the resistor layer. The capacitor layer has a capacitor disposed over and electrically connected with the resistor. Further, a semiconductor device that generates a constant output voltage from an input voltage includes a semiconductor substrate, a resistor layer, and a capacitor layer. The resistor layer is configured to overlie the semiconductor substrate. The resistor layer has a resistor disposed therewithin. The capacitor layer is configured to overlie the resistor layer. The capacitor layer has a capacitor disposed over and electrically connected with the resistor.

Abstract: A voltage regulating circuit has a first switch, a transformer and a second switch. The first switch has an input node, a first node and a second node. The transformer is connected to the switches has a first coil and a second coil. The first coil and the second coil respectively have an end, and the second coil is connected to the first coil in series at a node. The node between the first and second coils is connected to the second node of the first switch. The second switch is connected to the transformer and has a first node, a second node and an output node. The first node is connected to the end of the first coil. The second node is connected to the first node of the first switch. The transformer will not heat up when the transformer needs not to be used.

Abstract: A power circuit in a battery powered portable communication terminal, having a battery and a transmission power amplifier for TDMA (Time Division Multiple Access) or TDD (Time Division Duplex) signals includes a power accumulator, a battery output current limiter, and a control circuit to control the current limiter and to connect the power accumulator to the battery and to the transmission power amplifier depending on whether the transmission power amplifier is transmitting a signal burst. The control circuit controls the battery to charge the power accumulator during a non-burst period. During burst periods, when the transmission power amplifier requires higher power, the control circuit connects the power accumulator to the transmission power amplifier, to supplement the current-limited current provided by the battery and provide a total current to the power amplifier that is higher than the battery output current.

Abstract: A power circuit is provided which is capable of lengthening use time of a battery in a portable communication terminal of a TDMA (Time Division Multiple Access) or TDD (Time Division Duplex) type portable communication devices, and of making them compact and lightweight. Since, by using a control circuit, an output current having been limited to become a pre-set current value is supplied from the battery to a transmission power amplifier and an electrical double layer capacitor is charged so that power is accumulated therein and since power is applied from the electrical double layer capacitor to both the control circuit and the transmission power amplifier, even if power consumption of the transmission power amplifier increases during a burst period, a drop of the output voltage from the battery is small. Therefore, time required for the output voltage to reach a terminating voltage in the battery is made longer and a life of the battery can be lengthened.

Abstract: A power regulation system is coupled to an AC power source outputting an input voltage. The system has a first transformer to receive the input voltage and generate a control voltage. The system also has a second transformer that has a primary coil and a secondary coil. The primary coil and secondary coil of the second transformer are electromagnetically coupled to each other and so arranged that when the control voltage from the first transformer is applied to the primary coil, an output voltage is generated between a first end and a second end of the secondary coil, wherein the output voltage is substantially 180° out of phase from the input voltage so as to generate an effective voltage applied to the load, and wherein the effective voltage is less than the input voltage and substantially equals to the difference between the input voltage and the output voltage, resulting a reduction in power consumption of the load.

Abstract: A power regulation system is coupled to an AC power source outputting an input voltage. The system has a first transformer to receive the input voltage and generate a control voltage. The system also has a second transformer that has a primary coil and a secondary coil. The primary coil and secondary coil of the second transformer are electromagnetically coupled to each other and so arranged that when the control voltage from the first transformer is applied to the primary coil, an output voltage is generated between a first end and a second end of the secondary coil, wherein the output voltage is substantially 180° out of phase from the input voltage so as to generate an effective voltage applied to the load, and wherein the effective voltage is less than the input voltage and substantially equals to the difference between the input voltage and the output voltage, resulting a reduction in power consumption of the load.

Abstract: A system and method regulates an alternator and includes a circuit for digitally generating a sawtooth waveform. An error amplifier circuit generates a divided down and error amplified alternator system voltage. A comparator circuit receives and compares to each other the digitally generated sawtooth waveform and the error amplified alternator system voltage and has an output to produce an alternator field input signal used for driving the field of an alternator.

Abstract: An enhancement mode JFET as a switching device in a buck converter circuit combined with a single rectifier diode and an inductor. A control circuit coupled to the gate of the JFET switches the JFET between a current conducting state and a current blocking state. The ratio of converter dc output voltage to converter dc input voltage is determined by the ratio of JFET conducting time to the sum of JFET conducting time and JFET blocking time. This pulse width modulation scheme is thus used to adjust the dc output voltage level. Limits on both frequency of operation and duty cycle result from slow switching speeds. Each time a device switches between states, a certain amount of energy is lost. The slower the device switching time, the greater the power loss in the circuit. The effects become very important in high frequency (fast switching) and/or high power circuits where as much as 50% of the losses are due to excessive switch transition time.

Abstract: A voltage regulator apparatus comprises a transformer having a primary winding and a secondary winding, a plurality of further windings selectively connected to one of the primary winding and secondary winding, and a plurality of solid state selectors respectively coupled to each of the plurality of further windings to one of i) connect the further winding in series with the primary winding or the secondary winding and ii) bypass the further winding.

Abstract: An AC voltage regulator, which not only has a fast response speed with respect to input voltage fluctuations but also is small in size and light in weight and is capable to boost an input voltage, comprises a high-frequency transformer 4, a first bi-directional semiconductor switch circuit 3, a second bi-directional semiconductor switch circuit 5 and a third bi-directional semiconductor switch circuit 6; an input AC voltage is ring-modulated by the first bi-directional semiconductor switch circuit 3 and the obtained ring-modulated voltage is transformed at a high frequency by the high-frequency transformer 4 and then demodulated by the second bi-directional semiconductor switch circuit 5, and the obtained AC demodulated voltage is added to the input AC voltage to produce an AC raised voltage, and the AC raised voltage is pulse width modulated by the third bi-directional semiconductor switch circuit 6, which is controlled to become ON only while the second bi-directional semiconductor switch circuit 5 is OFF,

Abstract: A converter for converting an input voltage (Ui) into an output voltage (U0). The converter has several modes of operation. The converter can, for example, operate in an up-conversion mode, a down-conversion mode, or a window conversion mode. The converter has at least one switch (S1-S4) for controlling the converter so as to obtain a desired value of the output voltage (U0) in the up-conversion mode and in the down-conversion mode. This is achieved by changing the duty cycle of a binary signal (BS) which controls the switch (S1-S4). The converter further includes means (DMNS) for detecting the duty cycle of the binary signal (BS). This duty cycle is compared with a reference duty cycle (RFDCCL). The result of this comparison is used for deciding whether or not to change over from the up-conversion mode (or the down-conversion mode) to the window conversion mode. In the window conversion mode each switch (S1-S4) in the converter is permanently closed or open.

Abstract: Apparatus and method is disclosed for overcoming the voltage attenuation and ground shifts normally associated with providing DC power to distributed loads from a DC power supply without the need for excessively large conductors, the need to distribute the DC power supply or the need to provide converters at or near each load. Reasonably accurate voltage regulation at each load is provided according to the invention while using low but not insignificant resistance power conductors by providing similarly low resistance voltage sense conductors. The loads are connected between the sense conductors in a distributed fashion. Current approximating that drawn by each load is injected from the power conductors to the sense conductors at or near each load. Dynamic current requirements are supplied by capacitors connected across each load, usually mounted on the load circuit boards.

Abstract: A magamp circuit including a saturable reactor for regulating the output energy delivered to a load and having a protective circuit for restricting energy flow to the load in the event of occurrence of a short-circuit at the load. Output energy fluctuations are reduced through the use of a non-linear feed forward response circuit. A circuit which compensates for an unwanted voltage reset applied to the saturable reactor due to reverse current leakage or reverse recovery energy of a protective diode is also provided.

Abstract: A static voltage regulator consists of a booster transformer, a regulator transformer, an electronic switching system and a control system. The booster transformer includes a booster primary winding and a booster secondary winding. The booster secondary is provided in series with the input and output terminals of the regulator so as to produce an output voltage. The regulator transformer includes a regulator primary winding and a regulator secondary winding. The regulator primary is electrically coupled to the output. The electronic switching system is coupled between the regulator secondary and the booster primary for providing a voltage to the booster primary. The control system includes a voltage sensor for sensing a voltage at the input, and a gating system coupled to the switching system for switching the output voltage in response to changes in the sensed input voltage.

Abstract: An tap changer for a voltage regulator including a tap positionable to vary the winding ratio of the transformer in response to changes in an electric load on the transformer is disclosed herein. The transformer includes a potentiometer mechanically coupled to the tap changer motor and immersed in the coolant of the tap changer, wherein the potentiometer generates a voltage representative of the position of the tap. An analog-to-digital conversion circuit converts the voltage to a digital signal representative thereof, and a microprocessor coupled to the analog-to-digital conversion circuit compares the digital signal to digital data representative of the full voltage range of the potentiometer which is correlated to the actual position of the tap.

Abstract: A tap changer including a tap positionable to vary the winding ratio of the transformer in response to changes in an electric load on the transformer is disclosed herein. The transformer includes an electric drive which is responsive to raise or lower signals applied thereto in order to selectively position the tap by the raising or lowering of the tap and thereby raising or lowering the transformer winding ratio. Upon sensing the current of the motor control signals, an up/down counter is incremented or decremented. Accordingly, when a tap change signal is detected, the direction of tap changer movement may be determined, based upon the value of the up/down counter. In this way the tap position is also accurately determined and known.

Abstract: A tap changer including a tap positionable to vary the winding ratio of the transformer in response to changes in an electric load on the transformer is disclosed herein. The transformer includes an electric drive which is electrically powered to selectively position the tap to effect incremental changes of the winding ratio. The transformer includes a monitoring system which monitors the load voltage of the transformer with at least one potential transformer which produces signals which are converted to digital data values stored in a circular data buffer. Each time control signals are applied to the electric drive and a subsequent tap change indication is detected, the first and last data values in the circular buffer are compared, and when the difference between the values exceeds a predetermine limit, the system updates a tap position value which represents the position of the tap.

Abstract: A microcontroller-based tap-changer controller including apparatus for keeping track of an electrically closed tap position and for automatically changing the tap setting of load tap-changing transformers and regulators; the tap-changer controller further utilizes the "keep-track" tap position to calculate the source voltage of the regulator for reverse power operations; and, a method for paralleling tap-changing transformers and regulators utilizing the circulating current of the units.

Abstract: An AC voltage regulator to be used to regulate voltage fluctuations both above and below a desired voltage output, the regulator including a regulator input connected with an AC power source, a regulator output connected with a load, and a single regulator transformer having a power winding and an inducing winding. The power winding is connected in series between the regulator input and the regulator output and the inducing winding, which is generally electrically isolated from the power winding, is structured and disposed to selectively induce a low voltage on the power winding. Further, a plurality of high frequency AC switches are included so as to variably set a plurality of connection topologies, each connection topology being specifically structured either to maintain voltage passing through the regulator constant, to step-up the voltage or to step-down the voltage, the various switches being variably positionable to provide for precise, gradual regulated adjustment of the output voltage.

Abstract: A power switching circuit selectively connects an electrical load having first and second input connections to any one of a plurality of branch power circuits. Each branch circuit includes a first and second conductor defining a relative voltage therebetween. The power switching circuit includes a selector switch for selecting which of the branch circuits is to be connected to the load. A triac is electrically connected to the first conductor of each branch circuit and to the first input connection of the load for selectively electrically connecting one of the first conductors to the first input connection. A triac is electrically connected to the second conductor of each branch circuit and to the second input connection of the load for selectively electrically connecting one of the second conductors to the second input connection.

Abstract: A soft-switching circuit for achieving zero-voltage-transition (ZVT) type commutation in switching power converters includes a magnetic feedback circuit for achieving substantially zero voltage turn on of the active power switches and for achieving zero voltage turn off of the passive power switches of the switching power converter.

Abstract: Disclosed is a supply of the AC-DC converter type where the regulation is achieved by successive operations for charging and discharging a capacitor. The supply includes an input oscillator circuit, the period of which is very small as compared with that of the input AC voltage. A first switch is closed during the time necessary for the charging of the capacitor of the oscillator circuit. When it opens, a second switch gets closed to enable the transfer of energy towards the load. The regulation is done by an oscillator circuit which is controlled by an error voltage on the load and which triggers a monostable trigger circuit to close the first switch and open the second one during the period when this monostable trigger circuit is in its quasi-stable state.

Abstract: A waveform corrector for providing correction to three-phase electrical power to correct for transient and harmonic distortion arising from electrical power cable reactance wherein the cable head end voltage and current are sensed without load end voltage or current sensing. Phase and neutral current values are sensed and corrected with predetermined values of cable resistance and inductance to provide a corrected sine wave voltage at the load end of the cable achieved by inserting a dynamic correction voltage in series with the electrical output of the waveform corrector.

Abstract: A three phase voltage regulator system uses a transformer having primary, secondary and tertiary windings for each phase which are closely magnetically coupled to each other and are connected to provide a four wire (wye) three phase output on three hot lines with a neutral line, and a three phase input which is also wye connected, but where the neutral need not be connected to an input neutral line. The voltage across each primary phase winding is regulated by a series connected regulator circuit. The regulator circuit may derive voltages from the respective tertiary winding which either bucks (subtracts from) or boosts (adds to) the input voltage so as to maintain the primary winding voltage substantially constant. A controller which is responsive to the output voltage from the secondary windings controls the regulators and responds to output voltages of their respective phases.

Abstract: A load is supplied by a transformer supplied via a voltage regulator and thyristor network. The thyristor network and regulator are simultaneously controlled to respond to changes in the load and in practice the thryistors respond rapidly and are re-adjusted as the regulator is inherently more slowly adjusted. The result is that the thyristors produce minimum reflected harmonics overall in the mains and an optimum power factor can be achieved for each power setting.

Abstract: Regulation of an AC or DC voltage is achieved by processing a major portion of the prime power through a square wave inverter and a small portion of the prime power through a pulse width modulated switching regulator. The methods of regulation generally comprises the steps of: processing the unregulated input voltage to provide an output voltage; regulating an unregulated portion of the input voltage in response to a feedback signal indicative of the output voltage to provide a regulating voltage; and combining the regulating voltage with the output voltage to generate a regulated output voltage. The regulator circuit includes a square wave inverter circuit that produces a voltage in an output transformer, while a pulse width modulator regulates the output voltage in response to a feedback signal.

Abstract: To produce a high current carring inductor with a high inductance value in space normally too small, a transformer is chosen which meets space requirements and has a primary winding of sufficient current capacity, but too little inductance. A bidirectional current source drives the secondary winding under control of a feedback circuit in response to sensed primary winding current to effectively multiply the primary winding inductance.

Abstract: A power current regulator, in particular for airport lighting, includes transformers in series with intermediate taps on their secondary windings staged a various different numerical weights. In each case, one of said taps is selected by a latch memory (MV) preceded by an up/down counter (CD). These circuits are actuated by a control circuit as a function of the current detected by a current transformer (TIC) connected in series with the load.

Abstract: A pulse-width ac voltage regulator that provides a precisely ac output voltage without the need for any inefficient protective circuitry for ensuring proper operation when it repeatedly switches between its two alternative operating modes. A transformer is arranged with a first winding connected between an input terminal and an output terminal and a second winding connected between one end of the first winding and a control terminal. A special switch assembly including four separate circuits, each having a series connected transistor and diode, is controllably switched such that the second winding is alternatively shorted or excited, to provide a stepped-up (or stepped-down) voltage out of the first winding. The transistors are controllably switched at a frequency substantially greater than that of the ac input signal and at a duty cycle selected to provide the desired ac output voltage.