Abstract: A ZCVTT switching circuit includes a switch, and a passive block coupled to the switch and configured to damp an input signal from the switch. The switching circuit further includes a recycle positive energy (RPE) block coupled to the passive block and configured to recycle positive energy from a positive spike from the passive block, and a recycle negative energy (RNE) block coupled to the passive block and configured to recycle negative energy from a negative spike from the passive block.

Abstract: A buck-boost converter circuit, such as a non-inverting buck-boost converter, can include two separate control loop circuits to separately control operation of the buck circuit and the boost circuit. The control loop circuits may include two different voltage reference signals, two different current reference signals, two different current feedback signals, two different voltage feedback signals, or a combination thereof. The buck-boost converter circuit can operate in three modes: a buck mode, a transition mode, and a boost mode.

Abstract: One or more embodiments relate to a regulation loop control circuit for regulation of a parameter such as an input voltage or output voltage for a buck-boost converter. In these and other embodiments, the regulation loop control circuit is configured to select between an input voltage loop for regulation of the input voltage or an output voltage loop for regulation of the output voltage in response to an input voltage error, an output voltage error, and a threshold detector to protect the converter without sacrificing output voltage regulation and transient response.

Abstract: A first circuit generates and outputs a transmission signal to a first end and a second end of a first coil in response to variation in logical value of an input first signal. A detection circuit detects a voltage signal generated at each of a first end and a second end and outputs a second signal which reflects the first signal based on a result of detection. A control circuit controls a voltage to be applied across opposing ends of each of a first diode and a second diode of a first rectifier circuit and a voltage to be applied to opposing ends of each of a third diode and a fourth diode of a second rectifier circuit.

Abstract: A coil structure includes: a magnetic core that defines a closed loop magnetic path in which a magnetic flux flows, the magnetic core including a core leg; a coil that is wound around the core leg about a coil axis extending in a first direction, the coil generating the magnetic flux; a detour member that is separate from the magnetic core, the detour member defining a detour magnetic path that detours around the closed loop magnetic path between first and second points, the detour member including a first piece that defines the first point and a second piece that defines the second point; and a fixing portion that includes an adjoining member adjoining the core leg and a connecting portion connecting at least one of the first piece and the second piece to the adjoining member and fixes positional relations among the core leg and the first and second points.

Abstract: A DC-DC converter, capable of operation in either a boost or buck mode, includes a voltage source connected to an input switch through an inductive element such that a closed loop is formed. The DC-DC converter includes a switching network that receives one or more clock signals from an external clock source. The switching network has a first terminal connected to the inductive element, a second terminal connected to a first capacitor, and a third terminal connected to a second capacitor, wherein the switching network enables charging of the first capacitor and the second capacitor based on one or more clock signals such that the first capacitor and the second capacitor are charged alternately. The DC-DC converter includes a filter connected to a fourth terminal of the switching network, wherein the first capacitor and the second capacitor discharge alternately based on the one or more clock signals through the filter.

Abstract: A regenerative load electric power management system can include a system bus, an input filter coupled to the system bus, a first bidirectional solid state power controller coupled to the system bus, a motor drive inverter coupled to the input filter, a second bidirectional solid state power controller coupled to the motor drive inverter, a bidirectional direct current DC-DC converter coupled to the second bidirectional solid state power controller and an energy storage bus coupled to the bidirectional DC-DC converter, the energy storage bus providing access to an energy storage device.

Abstract: A controller and an output filter for a power converter, and a power converter employing at least one of the same. In one embodiment, the controller includes an error amplifier with first and second input terminals coupled to one of an operating characteristic and a reference voltage of the power converter, and a switch configured to couple the first and second input terminals to one of the operating characteristic and the reference voltage as a function of a power conversion mode of the power converter. In one embodiment, the output filter includes an output filter capacitor with a first terminal coupled to a first output terminal of a power converter, and an output filter inductor coupled between a second terminal of the output filter capacitor and a second output terminal of the power converter.

Abstract: To provide a DC/DC converter capable of down-sizing magnetic components and varying boosting and bucking ratios, and a bidirectional boosting-bucking operations, a bidirectional boosting-bucking magnetic-field cancellation type of DC/DC converter (10) is provided which includes: a first voltage side port (P1), a second voltage side port (P2); a common reference terminal (CP), a smoothing capacitor (C1), four switching elements (SW1, SW2, SW3, SW4), an inductors (L1, L2), a magnetic-field cancellation type transformer T including a primary winding (L3) and a secondary winging (L4), four switching elements (SW5, SW6, SW7, SW8), and a smoothing capacitor (C2).

Abstract: Disclosed is a charge pump system having a charge pump with a switch control input, a voltage output terminal, a high voltage terminal coupled to a high voltage node and a low voltage terminal coupled to a low voltage node. Also included is a first buck/boost switch having a first terminal coupled to the voltage output terminal, a second terminal coupled to a first output node, and a first control terminal for receiving a first control signal. A second buck/boost switch includes a first terminal coupled to the voltage output terminal, a second terminal coupled to a second output node, and a control terminal for receiving a second control signal. Further included is a switch controller that is adapted to generate the first control signal and the second control signal such that voltage pulses output from the first output node and the second output node, respectively, are asymmetrical and coincidental.

Abstract: An actuator control system includes a controller and a buck-boost circuit. The controller is configured to direct power from a power source to an actuator. The actuator is coupled to a control device to apply a force related to operation of a vehicle. The buck-boost circuit is configured to direct excess power generated by the actuator to an energy storage device when an actuator power level satisfies an anticipated power level.

Abstract: A switched-mode power converter power converter, in one preferred embodiment with eight switches connected between three ports and an inductive element, with a donor (charging) port, a receptor port (load) and donor/receptor port (storage) operated so that energy may be switch between any of the ports regardless of the polarity and magnitude of the inductor current at the beginning of a chopping cycle. In one embodiment of the invention power conversion and power factor correction are accomplished in a single stage.

Abstract: When a commercial power supply E operates normally, converter sections PFC1, PFC2 connected in parallel to each other can operate to approximate the input current from the commercial power supply E to the waveform and phase of the input voltage to correct a power factor while supplying stabilized output voltages Vo1, Vo2 to a load. When the voltage of the commercial power supply E drops, the smoothing capacitor Co1 operates as an input power supply to power the converter section PFC2, which allows the smoothing capacitor Co2 to supply the stabilized output voltage Vo2 to the load.

Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to solve the task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.

Abstract: The present invention relates to a single-stage zero-current switching driving circuit for ultrasonic motor, which comprises: a buck-boost converter and a zero-current switching resonant inverter. The driving circuit according to the present invention integrates the buck-boost converter and the resonant inverter into a single-stage structure, so that the buck-boost converter and the resonant inverter share an active switch and a trigger signal, and therefore, the circuit is simplified and the loss caused by stage switching is reduced. Moreover, the buck-boost converter operates in a discontinuous-conduction mode (DCM), which allows the circuit to have high power factor, and enables the active switch to be capable of zero-current switching (ZCS), so that the loss caused by switching is largely reduced. In the driving circuit according to the present invention, there's no interaction of power between the buck-boost converter and the resonant inverter, so that the two circuits can be analyzed individually.

Abstract: A semiconductor device is provides which includes: a first boost circuit that generates a first boost voltage by boosting an external voltage and supplies the first boost voltage to an internal circuit; and a first circuit that supplies the external voltage to an output of the first boost circuit when power is turned on and supplies the first boost voltage to the output of the first boost circuit when the external voltage reaches a given voltage.

Abstract: A method of controlling an uninterruptible power supply apparatus (UPS) is provided. The UPS apparatus includes at least an AC input voltage, a DC input voltage and a single-phase AC/AC converter. The single-phase AC/AC converter includes an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm. The method includes steps of: controlling the bus voltage to have a DC component and full-wave rectifying component, and setting a bus voltage parameter K so that the bus voltage approaches to a full-wave rectifying voltage when K approaches to 1, wherein 0?K?1.

Abstract: A buck converter for use in controlling a motor in accordance with an embodiment of the present invention includes a power input operable for connection to a DC power supply, a switch for selectively connecting the motor to the power supply, a pulse width modulation controller operable to provide a pulse width modulation signal to the switch, wherein the switch connects the motor to the power supply based on the pulse width modulation signal, and a voltage shifting capacitor connected across the switch and in series with a diode. The buck converter may include a shift control device operable to control a voltage across the voltage shifting capacitor.

Abstract: A power management apparatus includes a first electrical lead and a second electrical lead. The first electrical lead routes electrical current at a first electrical lead electrical potential level and the second electrical lead route electrical current at a second current port electrical potential level. The power management apparatus further includes a first electrical parameter sensor configured to measure a first electrical lead electrical parameter and a second electrical parameter sensor configured to measure a second electrical lead electrical parameter. The power management apparatus further comprises a buck boost converter electrically coupled to both the first electrical lead and the second electrical lead. The buck boost converter is configured to convert electrical current between the first electrical lead electric potential level and the second electrical lead electric potential level at a controlled potential conversion level.

Abstract: A device having a switch with a voltage applied across the switch. A current sensing circuit is connected to one terminal of the switch. The current sensing circuit receives power independently of the voltage applied across the switch. The power supply shares the other terminal of the switch with the current sensing circuit. The switch is adapted for opening and closing. When the switch closes, the current sensing circuit senses current through the switch and upon opening the switch the high voltage of the switch is blocked from the current sensing circuit. The sense current is caused to flow from the current sensing circuit to the other terminal when the switch is closed. The flow of the sense current produces a voltage which is compared differentially to another voltage referenced by the other terminal.

Abstract: A method of generating an output DC voltage of a gas discharge process voltage supply unit, in which in a first voltage transformation stage a first DC voltage is transformed into a second DC voltage of a predetermined voltage range, and the output DC voltage is generated from the second DC voltage in a second voltage transformation stage. A switching element of at least one boost converter is switched with a controlled pulse-duty factor for generating the output DC voltage in the second voltage transformation stage. This method permits striking and maintenance of a plasma process.

Abstract: A circuit for controlling pulsed current to a load, one application of which is in LED dimmer circuitry, comprises first and second reference nodes for receiving a supply voltage, an input node for receiving a timing signal such as a PWM signal, and a controlled switch coupled between the first and second reference voltage nodes for supplying current to the load. Pull-up circuitry may be coupled between a control electrode of the controlled switch and first reference voltage node, and a pull-down switch coupled between the control electrode and second reference voltage node. A control circuit coupled between the input node and control electrode of the controlled switch is configured to control the controlled switch in response to the timing signal. The circuit may further include a reference voltage source configured for producing a voltage of magnitude independent of supply voltage magnitude.

Abstract: A step-up converter includes input and output terminals, step-up conversion circuitry, a first feedback path and a drive circuit. The input terminals are configured to receive an input DC voltage and the output terminals configured to provide an output DC voltage. The step-up conversion circuitry is coupled between the input terminals and the output terminals and includes a switching element. The first feedback path has a regulator arrangement configured to provide a regulating signal which is dependent on the output voltage. The drive circuit is configured to provide a pulse-width-modulated drive signal for the switching element and is supplied with the regulating signal, wherein the drive circuit is configured to generate the drive signal in a manner that corresponds to the input voltage.

Abstract: A boost snubber circuit structure applied in a power supply having a boost circuit and a power conversion unit, wherein the boost circuit includes a boost unit connected to a switch element, a boost control unit for generating a driving signal to drive the switch element to control the charge/discharge of the boost unit, and a boost snubber unit for obtaining a voltage difference between a reference voltage and a detection signal and modulating the magnitude of the reference voltage or the detection signal to change the voltage difference and control the duration of outputting the driving signal. The voltage difference between the reference voltage and the detection signal determines the duration of outputting the driving signal. By controlling the voltage difference between the detection signal and the boost level, the invention prevents an occurrence of an inrush current caused by a too-large duration of generating the driving signal.

Abstract: The present invention discloses a transformer used in a charger circuit, in which the input side of the transformer is connected to an AC input and PWM control circuit of the charger circuit, the output side of the transformer is connected to a constant current and/or constant voltage control circuit of the charger circuit. The AC input, PWM control circuit, the constant current and/or constant voltage control circuit are coupled through an optical coupling element, wherein the transformer includes a main output winding and an auxiliary output winding, and the auxiliary output winding is used to supply power for the optical coupling element and the constant current and/or constant voltage control circuit. The present invention further provides a high performance charger circuit adopting the transformer described above for improving electromagnetic compatibility, conversion efficiency and short circuit characteristic.

Abstract: A boost control module operates semiconductor switches of a boost converter circuit in an avalanche mode to precharge a boost output capacitor. The boost control module comprises a switching module that complementarily transitions a first semiconductor switch and a second semiconductor switch between ON and OFF states when a current does not exceed a maximum current threshold. The switching module transitions the first semiconductor switch and the second semiconductor switch to the OFF state when the current exceeds the maximum current threshold. The switching module maintains the first semiconductor switch and the second semiconductor switch in the OFF state until at least one of the inductor current is less than or equal to a minimum current threshold.

Abstract: An improved Single-Stage Buck-Boost inverter (S2B2 Inverter) is provided, using only three or four power semiconductor switches and two coupled inductors in a flyback arrangement. The inverter can handle a wide range of dc input voltages and produce a fixed ac output voltage. The inverter is well suited to distributed power generation systems such as photovoltaic and wind power and fuel cells, for standalone or grid connected applications. The inverter has a single charge loop, a positive discharge loop and a negative discharge loop.

Abstract: The present invention provides a low-cost current detection device having a magnetic sensor easily placed on a choke coil, wherein assembly and manufacturing costs are reduced and a product is miniaturized. A current detection device including a choke coil for smoothing an input current or an output current and a magnetic sensor 1a built into the choke coil to detect the input current or output current, wherein the choke coil is composed of: a pair of cores 5 provided with an outer magnetic leg 5a constituting a closed magnetic circuit and a center magnetic leg 5b for providing a gap; and an air core coil 6 mounted on the center magnetic leg 5b, and space 6b is provided to a part of winding of the air core coil 6 with the magnetic sensor 1a placed in the gap between the space 6b and the center magnetic leg 5b.

Abstract: A PFC circuit comprises a first converter and a second converter and a multi-port electromagnetic device. The first converter has a first inductive element and the second converter has a second inductive element. The multi-port electromagnetic device comprises a first magnetic core having a first closed flux path and a second magnetic core having a second closed flux path, with the first closed flux path being independent of the second closed flux path. The first inductive element of the first boost circuit comprises a first winding that electromagnetically couples the first magnetic core to the second magnetic core and the second inductive element of the second boost circuit comprises a second winding that electromagnetically couples the first magnetic core to the second magnetic core independent of the electromagnetic coupling of the first winding such that current application in one windings does not induce a substantial voltage in the other.

Abstract: A plurality of constant ON-time buck converters are coupled to a common load. The output of each buck converter is coupled to a common load via a series sense resistor. The regulated output voltage across the common load is compared to a reference voltage to generate a start signal. The start signal is alternately coupled to the controller on each buck converter. The ON-time of a master buck converter is terminated when a ramp signal generated from the regulator input voltage exceeds the reference voltage. All other slave converters have an ON-time pulse started by the start signal and stopped by comparing a sense voltage corresponding to their output current during their ON-time pulse to the peak current in the master converter during its ON-time. A counting circuit with an output corresponding to each of the plurality of buck converters is used to select which buck converter receives the start signal.

Abstract: In accordance with an embodiment of the disclosed matter, a voltage regulator may supply power to a component within a computer system. A timer may be provided. The voltage regulator may operate synchronously, and when the timer expires the voltage regulator may operate non-synchronously. For one embodiment, the voltage regulator may operate non-synchronously when the timer expires and the component is in a sleep state.

Abstract: A multi-lamp drive device comprises a transformer, a drive circuit and at least a balanced inductor. The magnetic core of the transformer has a first side column, a second side column and at least a central column. A primary coil and a secondary coil are wound around the first side column and the second side column, respectively. The drive circuit can output an excitation power source to the transformer for driving lamps to be on based on the energy conversion characteristic of the transformer. With the help of the central column, the transformer can guide the counter magnetic flux generated by the load current without interfering the power conversion action of the transformer. Moreover, heat generated by the transformer due to a too larger load current can be reduced, and the protection function for the transformer during short circuit can also be accomplished.

Abstract: A system for electronically actuating valves in an engine. The system includes first and second voltage sources, and a plurality of valve actuator subsystems coupled therebetween. Each valve actuator subsystem has a valve actuator and a switch configured to selectively control application of voltage to the valve actuator to thereby selectively control energization of the valve actuator. The system also includes a dissipation switch operatively coupled with the valve actuator subsystems, the dissipation switch being selectively operable to control dissipation of energy from any of the valve actuators.

Abstract: A system for electronically actuating valves in an engine. The system includes a first voltage source, a second voltage source, and plural valve actuator subsystems coupled between the first voltage source and the second voltage source. Each valve actuator subsystem has a valve actuator and a switch. One of the actuator subsystems is configured so that current flows from the first voltage source through the valve actuator of the subsystem when the switch is in a first position, and when the switch is in a second position, current is permitted to flow from the valve actuator toward the second voltage source. Another of the valve actuator subsystems is configured so that current flows from the second voltage source through the valve actuator of the subsystem when the switch is in a first position, and when the switch is in a second position, current is permitted to flow from the valve actuator toward the first voltage source.

Abstract: The present invention is an AC voltage regulator which includes a feed-forward circuit and a differential amplifier which continuously and instantaneously compares the incoming AC voltage to a locally generated, amplitude-stabilized wave form. The local wave form is generated substantially frequency and phase synchronized to the incoming voltage. The output of the differential amplifier drives a power amplifier. The power amplifier output is arranged to continuously buck or boost the incoming AC voltage, depending on the polarity (phase) of the signal from the differential amplifier. The system corrects even subcycle disturbances in the incoming wave form. The present invention is also a method for regulating AC voltage.

Abstract: A boosting and step-down switching regulator includes one error amplifying circuit, and an output of the error amplifying circuit is compared with a triangular wave for boosting and a triangular wave for step-down different in voltage level from each other but synchronous with each other in comparison circuits, respectively, to switch the boosting operation and the step-down operation over to each other. Thus, the boosting operation and the step-down operation can be readily switched over to each other irrespective of an input voltage and an output voltage.

Abstract: An objective of this invention is to provide a drive control device to control the drive applied to a high-speed rotor unit which would have no circuits in either its pump unit A or its power supply unit B that would limit the use of the device with various types of rotor units, which could easily be used with various types of rotor units, and whose power supply unit B could be used generally. The drive control device for controlling a high-speed rotor unit according to this invention has a power supply unit contains a set of tables of constants needed to control the various types of rotor units with which the drive control device might be used. These constants allow the rotation of the high-speed rotor unit to be adjusted or set according to the type of rotor unit. A signal intended to detect and indicate the type of rotor unit to be driven by the rotor is automatically detected and input before the motor is driven. Based on this signal, the appropriate table is selected.

Abstract: A low power loss boost converter of the discontinuous conduction type includes an inductor coupled between the boost converter input and a junction, a current rectifier coupled between the junction and the converter output, a switch coupled between the junction and common, and a switch capacitor coupled in parallel with the switch, the inductor and an energy storage capacitance associated with the input. The switch is alternately opened and closed in switching cycles which alternately energize the inductor and transfer the energy to the output load. Power losses are reduced by providing switch closure at a near zero voltage and current switch conditions produced by a circuit resonance. The capacitor reduces voltage across the switch during the switch open transient condition.

Abstract: An AC voltage regulator provides a desired AC voltage to a load. The desired AC voltage is within a predetermined range above and below that of an AC voltage source. The AC voltage regulator has a transformer, the secondary winding of which is configured to be placed in series with the AC voltage source and the load. A plurality of switches is configured to direct current from the AC voltage source through the primary winding of the transformer. The switches are further configured to control the direction in which current flows through the primary winding of the transformer. A pulse width modulator controls the switches according to a desired cycle period.

Abstract: An energy efficient uninterruptible regulated power supply includes a full wave rectifier that is responsive to AC main power generating an unregulated DC voltage signal, a power factor correcting boost converter coupled to receive and selectively increase the unregulated voltage signal to generate a boosted voltage signal, a battery and a single ended forward converter having a primary winding coupled to receive pulse width modulated energy from the boosted voltage signal and a secondary winding couple bidirectionally to the battery with pulse width modulated control. A first controller pulse width modulates the boosted voltage and battery signals coupled to the primary and secondary windings, respectively, to regulate the output voltage while a second controller operates independently of the first controller pulse width modulate the boost converter to regulate the voltage of a transformer secondary signal that is coupled to the battery.

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: A controller for a two-switch buck-boost converter accomplishes one-at-a-time switch control by simultaneously employing an analog error signal to control one drive output and an analog inversion of that error signal, with respect to a voltage that is equal to the voltage excursion limit of a timing ramp signal, to control the other drive output. In a second embodiment of the invention, a controller employs a comparator to compare an analog error signal against a given voltage excursion limit of a timing ramp signal to perform the functions of determining which of two drive outputs is to be enabled to be modulated and of modifying the voltage excursion limits of the timing ramp signal such that the voltage excursion limit compared by the comparator is switched between two different voltage excursion limits.

Abstract: A series-parallel active power line conditioner is provide having improved peak voltage regulation capability when compared with the prior art. The DC energy level in the DC link between the series and parallel inverters is temporarily increased when the AC input voltage is not within the linear regulation range of the active power line conditioner. To effect this energy boosting function, control circuitry first determines the amount by which the average value of the AC input voltage is without the linear regulation range of the active power line conditioner. This information is then utilized to control the parallel inverter such that the DC energy level in the link is proportionally increased. A preselected maximum DC energy level is preferably chosen such that excessive AC input voltage variations will not cause further increases in the DC energy level.

Abstract: A circulating load apparatus for loading a power supply. The power supply has a power input terminal, a power output terminal and a power return terminal. The power supply provides an output voltage at the power output terminal with respect to the power return terminal. The output voltage of the power supply is controlled to be substantially identical in amplitude to the network voltage of a network source, provided at a network source terminal with respect to a source return terminal. The power supply, power return terminal is coupled to the network source, source return terminal. The power supply power input terminal is coupled to the network source terminal to be powered by voltage and current from the network source terminal. The circulating load apparatus has a voltage source for supplying a voltage between a first and second terminal. The voltage source is connected in series between the network source terminal and the power supply power output terminal.

Abstract: To increase the output voltage of a conventional rectifier bridge, one winding of an autotransformer is connected across a pair of a-c input terminals of the bridge through a thyristor which is turned on only when an output voltage increase is desired, and an extra diode is used to connect the other autotransformer winding to one of the d-c output terminals so that the boost voltage induced in the latter winding is added to the input voltage.

Abstract: An uninterruptible power supply device uses a transformer with a first primary winding and secondary winding tightly coupled to one another to transmit AC input electrical power to a voltage sensitive load. A series regulator switches taps in the first primary to keep the load output voltage within certain limits during minor variations in the AC input voltage. A standby inverter supplies standby power to the load after a loss or large variation in the AC input voltage by driving PWM pulses into a secondary primary winding of the transformer. The transformer loosely couples the second primary winding to the secondary winding to aid in synthesizing the output sinusoidal wave from the PWM pulses. The regulator opens all of the taps to prevent the inverter from supplying power to the AC input.

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.

Abstract: A voltage controlling transformer circuit comprises a setting unit to the input terminals of which an alternating input voltage is applied and the output terminals of which provide an alternating output voltage the amplitude of which can selectively be changed. For this purpose the setting unit comprises a transformer having a first winding connecting one of the input terminals with one of the output terminals while the other input terminal and the other output terminal are directly connected by a conductor. The transformer also comprises at least one further winding the number of turns of which is greater than the number of turns of the first winding, and to which different control voltages can be applied by means of switches in order to induce in the first winding a voltage the amplitude of which is, in dependence on the winding sense of the further winding, either additionally or subtractively imposed on the amplitude of the input voltage.

Abstract: A switching AC voltage regulator including a transformer, two solid state AC switches, and sensing means controlling the switches to produce the desired output voltage. The two switches conduct alternately and are switched at a rate much higher than the frequency of the regulated AC voltage. When the first switch is activated, the transformer is shorted out, causing the output of the transformer to equal the input. When the second switch is activated, normal transformer action occurs, creating an output voltage either higher or lower than the input, depending on the transformer arrangement. The duty cycle of the switches is varied to provide precise control of the output voltage.

Abstract: An AC voltage regulator maintains a predetermined, desired output voltage despite changes in the input voltage, the load, or other operating conditions. The regulator generates an AC reference voltage signal of the same frequency and in phase with the input voltage, and having an amplitude proportional to the predetermined, desired output voltage. The AC reference voltage signal is compared instantaneously to a portion of the actual output voltage to determine an error between the actual output voltage and the predetermined, desired output voltage. The error is instantaneously corrected by altering the actual output voltage to conform to the predetermined, desired output voltage.