Abstract: A power conversion device includes: a voltage conversion circuit that converts an AC voltage input into a DC voltage by PWM control and outputs the DC voltage; an input voltage detection circuit that detects the AC voltage input to the voltage conversion circuit and outputs a detection signal; an input current detection circuit that detects an AC current input to the voltage conversion circuit and outputs a detection signal; an output voltage detection circuit that detects the DC voltage output from the voltage conversion circuit and outputs a detection signal; and a control circuit that corrects a phase of a PWM signal for the PWM control based on the detection signal from the input voltage detection circuit, the detection signal from the input current detection circuit, and the detection signal from the output voltage detection circuit, and outputs the PWM signal corrected to the voltage conversion circuit.

Abstract: A power stage of a multi-phase power converter includes: a first switch device configured to connect an output node of the power stage to a supply voltage in a first switching state of the power stage; a second switch device configured to connect the output node to ground in a second switching state of the power stage; driver circuitry configured to set the power stage in either switching state or a non-switching state, a duration of each state and a timing transition between the states being indicated by a control signal; current sense circuitry configured to measure current flowing through at least one of the switch devices; and timing circuitry configured to adjust the timing transition between switching states so as to change an effective duration of the first and/or second switching state relative to a reference duration defined by the control signal, based on magnitude of the measured current.

Abstract: Methods and systems to reduce distortions induced in a voltage measurement wire. In an embodiment, a measurement wire is coupled to a head of an arc welding apparatus and to a feedback circuit to provide a head voltage and noise induced on the measurement wire to the feedback circuit. A reference wire is coupled to a reference node and to the feedback circuit to provide noise induced on the reference wire to the feedback circuit. The reference node may be proximate to and electrically isolated from the head, and the measurement wire and the reference wire may be arranged adjacent to one another (e.g., as a twisted pair), so that the similar distortions are induced in the measurement wire and the reference wire. The feedback circuit determines the head voltage as a difference between noise of the reference wire and the head voltage and noise of the first measurement wire.

Abstract: A sensor circuit (10), including a silicon photomultiplier, SiPM, sensor (20), a voltage source (32), a current-to-voltage converter (24), and a limiting bias circuit (34). The SiPM sensor (20) has avalanche photodiode, APD, elements (30) connected in parallel between a cathode (K) and an anode (A). The voltage source (32) is configured to apply a reversed bias voltage (Vb) across the SiPM sensor, so that each APD element operates in reverse-biased Geiger mode, and the APD elements operate in integration mode. The bias circuit (34) is connected between the voltage source (32) and the anode, and is configured to limit currents through the APD elements, and to present an AC load impedance for an alternating current within a predetermined operating frequency range (fo) generated by the APD elements at the anode (A) as well as a DC load impedance, such that said AC load impedance is lower than said DC load impedance.

Abstract: A power factor correction circuit, and methods of operation, is described, that can downconvert AC mains power to a lower power suitable for driving one or more LEDs. The power factor correction circuit can provide a regulated current, in a single-stage embodiment, and a regulated voltage, in a dual-stage embodiment. The power factor correction circuit can include an isolation transformer along with a switch for controlling downconversion. The power factor correction circuit can alternatively include a switch without isolation. Either way, the switch can have a duty cycle proportional to a desired downconversion from the AC mains signal, and can skip half cycles of the AC mains signal in order to reduce the downconverted output of the power factor correction circuit.

Abstract: A bleeder circuit emulator for use in a power converter to compensate and increase the current demand from the Triac dimmer above its holding current. The circuit includes an input voltage modifier and a leading edge dimming detection circuit. The input voltage modifier receives an input voltage signal that is representative of a magnitude of an input voltage of the power converter and selectively provides a modified input voltage signal to an input of a controller in response to receiving a control signal. The modified input voltage signal is representative of a value that is less than the magnitude of the input voltage. The leading edge dimming detection circuit generates the control signal to engage the input voltage modifier to generate the modified input voltage signal in response to detecting leading edge dimming at an input of the power converter.

Abstract: A dimmable switching mode LED driving circuit without phase angle measurement, including: a dimmer circuit for providing a phase-cut AC voltage; a bridge rectifier providing an input voltage by rectifying the phase-cut AC voltage; an electromagnetic interference filtering and energy storing circuit providing a line voltage according to the input voltage; a switching power converter converting the line voltage to an output current for an LED load under a control of a driving voltage; and a control unit including an on-time controller for operating in a constant on-time mode to determine an on time, where the on-time controller includes a voltage limiting circuit, a saw-tooth signal generator, and a comparison circuit to set a maximum limit on the on time.

Abstract: A dimmable switching mode LED driving circuit without phase angle measurement, including: a dimmer circuit for providing a phase-cut AC voltage; a bridge rectifier providing an input voltage by rectifying the phase-cut AC voltage; an electromagnetic interference filtering and energy storing circuit providing a line voltage according to the input voltage; a switching power converter converting the line voltage to an output current for an LED load under a control of a driving voltage; and a control unit using at least one feedback signal to perform a pulse width modulation operation to determine an on time for the switching voltage; wherein the control unit includes an on-time controller and a timer, the on-time controller determining the on time according to the at least one feedback signal, and the timer setting a maximum limit on the on time.

Abstract: A multiphase switching regulator includes a power stage with at least a first phase and a second phase for supplying power to a load through inductors coupling the phases to the load. The multiphase switching regulator is operated by switching the first phase at a higher switching frequency than the second phase via pulse width modulation (PWM) signals provided to the phases. A phase-specific target current is generated for each phase at the switching frequency for that phase based on the difference between an output voltage of the power stage and a reference voltage. The current in the inductors coupling the phases to the load is sensed, and a duty cycle of the PWM signal provided to each phase is adjusted based on the phase-specific target current and sensed inductor current for that phase.

Abstract: A driving frequency setting portion is provided. The driving frequency setting portion sets a switching frequency of a switching element on the basis of a notification from a driving phase number switching portion. A ripple current detected by a current sensor is in inverse proportion to inductance of reactor. Since a ripple current becomes the largest in the single-phase driving, in this embodiment, considering both the ripple current and switching loss, a switching frequency for the single-phase driving is set higher than a switching frequency for multiphase driving.

Abstract: The present invention includes: a zero crossing detection circuit which outputs a zero crossing signal when an inductor's regeneration period is completed; a light load detection circuit which compares an amplified error signal from an error amplifier and a threshold and outputs a light load signal; a timer circuit which outputs an intermittent operation enabling signal after a predetermined period based on the light load signal and zero crossing signal and outputs an intermittent operation disabling signal when the zero crossing signal is not outputted for a predetermined period; and an ON-OFF control controller which turns off a switching element when the amplified error signal falls below the threshold while the timer circuit is outputting the intermittent operation enabling signal, and turns on the switching element when the amplified error signal at least reaches or exceeds the threshold while the timer circuit is outputting the intermittent operation enabling signal.

Abstract: An electronic system includes a controller that controls switching in a switching power converter in accordance with a dynamically determined, minimum line voltage switching threshold based on one or more operating parameters of the electronic system. In at least one embodiment, the one or more operating parameters of the electronic system include power utilization of a load. The controller utilizes the dynamically determined, minimum line voltage switching threshold to determine when to enable and disable switching in the switching power converter. Since the controller bases determination of the dynamically determined, minimum line voltage switching threshold on power utilization of the load, the controller operates more efficiently by reducing switching losses while still meeting power demand by the load.

Abstract: A boost control section for controlling a converter includes a PI control section and a resonance suppression section. The PI control section calculates a basic command value based on a deviation between a drive voltage generated by the converter and a target voltage to equalize the drive voltage and the target voltage. The resonance suppression section calculates, based on the state of variation of the drive voltage, a correction value for correcting the basic command value to suppress the variation. The basic command value is corrected by adding the correction value. First and second drive pulses corresponding to the corrected command value are outputted to the converter.

Abstract: The present invention is directed to a device for regulating an amount of electrical power provided to at least one electrical load, the device comprising a control circuit disposed in the housing and including at least one switch device movable between a first switch state and a second switch state. The control circuit further includes a power control element that has a power control actuator configured to adjust the amount of power provided to the at least one electrical load. A variable control actuator is accessible to the user via the control aperture and coupled to the power control actuator via a linkage structure. The linkage structure further includes a pin and channel arrangement configured to convert a user control action into a power control actuator adjustment by translating rotational motion into linear motion or linear motion into rotational motion.

Abstract: A high voltage power supply is provided. The high voltage power supply includes a soft-start circuit unit which outputs a natural voltage that decreases exponentially as time elapses and converts the natural voltage into a forced voltage having a predetermined scale if an enable signal is applied, a controller which compares the natural voltage output from the soft-start circuit unit with a reference voltage and outputs a control signal, and a converting unit which delays outputting a final voltage during a first predetermined time period and outputs the final voltage, which gradually increases as time elapses according to the control signal.

Abstract: Systems, apparatus and methods for controlling the flow of power are provided. A current source (110) can be coupled to an uninterruptible power supply (120) to provide an uninterruptible current. A first service connection (190) can be coupled to the uninterruptible current using one or more conductors. A monitor (150), measuring one or more parameters, can be disposed in, on, or about the one or more conductors coupled to the first service connection (190). A first interruptible service connection (182) can be coupled to the current source (110) using one or more conductors. A first switch (172) can be disposed in, on, or about the conductors coupled to the one or more interruptible service connections (182). A control logic device (160) can be coupled to the monitor (150) and to the first switch (172) to interrupt the flow of current to the first interruptible service connection (182) when one or more parameters measured by the monitor (150) falls below a pre-determined threshold.

Abstract: A phase current sharing network that adjusts operation of a current mode multiphase switching regulator in which the phase current sharing network includes multiple synthetic ripple networks and a current share network. The regulator develops phase currents including ripple currents through corresponding phase inductors as controlled by corresponding pulse control signals. Each synthetic ripple networks develops a corresponding ripple voltage that simulates a corresponding phase ripple current and uses the ripple voltages to develop the pulse control signals. The current share network adjusts each ripple voltage by a combined adjustment value. The combined adjustment value is a combination of phase adjustment values in which each phase adjustment value is based on a difference between a corresponding one of ripple voltage and a reference voltage. Transconductance amplifiers may be used to convert the voltage differences to current adjust values applied to the ripple capacitors developing the ripple voltages.

Abstract: A sensing circuit senses a load current to generate a sensed signal. A comparator's output is set to a first value if the sensed signal is equal to or greater than a reference signal, and to a second value if the sensed signal is smaller than the reference signal. A one-shot timer generates a logic signal that transitions from a first state to a second state in response to a first occurrence of the first value of the comparator's output, or optionally in response to each subsequent occurrence of the first value of the comparator's output if the one-shot timer is rearmed. A selector sets a first limit for the current delivered to the load in response to the first state of the logic signal, and a second limit for the current delivered to the load in response to the second state of the logic signal.

Abstract: There is provided an output stage comprising: a phase splitter for receiving an input signal and for generating first and second drive signals of opposite phase in dependence thereon; a DC offset signal generator for generating a DC offset signal; an adder for adding the DC offset signal to the first drive signal to provide a first modified drive signal; a subtractor for subtracting the DC offset signal from the second drive signal to provide a second modified drive signal; a first drive transistor associated with a first power supply voltage, for generating a first output signal in dependence on the first modified drive signal; a second drive transistor associated with a second power supply voltage, for generating a second output signal in dependence on the second modified drive signal; and a combiner for combining the first and second output signals to generate a phase combined output signal.

Abstract: A dimmer adaptable to either two (H, DH) or three (H, N, DH) active wires includes a first full-wave rectifier (D1, D2, D3, D4) across an AC power hot (H) terminal and a dimmer hot (DH) terminal and a second full-wave rectifier (D1, D4, D5, D6) across the AC power hot (H) terminal and an AC power neutral (N) terminal. The dimmer operates in a two-wire configuration by drawing power through a load when a control circuit is not conducting or in a three-wire configuration, when the AC power neutral (N) terminal is connected, by drawing power from AC power hot (H) and AC power neutral (N) terminals. The dimmer operates according to a first set of preset dim levels when current is flowing through the first rectifier and according to a second set of preset dim levels when current is flowing through the second rectifier.

Abstract: A multi-phase power source device capable of easily changing the number of phases is realized. For example, a plurality of drive units POL[1]-POL[4] corresponding to the number of phases are provided, wherein each POL[n] receives a phase input signal PHI[n] serving as a pulse signal, and generates a phase output signal PHO[n] by delaying PHI[n] by a predetermined cycles of a clock signal CLK. PHI[n] and PHO[n] of each POL[n] are coupled in a ring, wherein each POL[n] performs a switching operation with PHI[n] or PHO[n] as a starting point. In this case, each POL[n] charges and discharges a capacitor Cct commonly coupled to each POL[n] with an equal current, and a frequency of CLK is determined based on this charge and discharge rate. That is, if the number of phases increases n times, the frequency of CLK will be automatically controlled to n times.

Abstract: A system for testing a DC power supply performance includes a load module electrically coupled to the DC power supply, a switch module electrically coupled to the DC power supply, a control module electrically coupled to the load module and the switch module respectively, and an indication module electrically coupled to the control module. The control module includes a judge module and a comparison module. The judge module is configured for receiving DC voltage signals from the DC power supply; wherein the judge module is capable of turning on when the DC power supply is normal. The comparison module is configured for comparing the DC voltage signals with a reference voltage; wherein the comparison module is capable of outputting a control signal when the DC voltage signals are greater than the reference voltage. The indication module is configured for receiving the control signal and indicating status of the DC power supply.

Abstract: A controller for dimming control of a switching power supply includes a phase angle measurement block and a drive logic block. The phase angle measurement block is to be coupled to receive an input sense signal. The phase angle measurement block generates a phase angle signal representative of a phase angle of an input voltage of the power supply in response to the input sense signal. The drive logic block is to be coupled to control switching of a switch included in the power supply. The drive logic block controls the switch in a closed loop dimming control when the phase angle is less than or equal to a phase threshold and in a open loop dimming control when the phase angle is greater than the phase threshold.

Abstract: A constant power control apparatus and a controlling method thereof are provided. The constant power control apparatus outputs output power to a load element. The constant power control apparatus includes a compensation and modification device, a constant power control device, and a power generation circuit. The compensation and modification device receives an expected output power voltage and a voltage feedback signal relating to the output power. The compensation and modification device transforms the expected output power voltage into a current reference value, and modifies the current reference value to generate a modified current reference value according to the voltage feedback signal. The constant power control device receives the modified current reference value and a current feedback signal relating to the output power, and generates a control signal for use in power modulation. The power generation circuit receives the control signal and outputs the output power.

Abstract: An electrical power diagnostic system includes a system housing, a power saw management system, and a user interface. The system housing is electrically connected with the power unit of the power saw, wherein the system housing includes a control panel provided thereon for allowing a user to adjust an operational parameter through the control panel. The power saw management system includes a control processor mounted within the system housing to electrically communicate with the power saw, wherein the control processor is pre-programmed to manage operational parameters of the power saw and supervise actual operation of the power saw machine and the saw blade in such a manner that when abnormal operating condition of the power saw machine is detected, the control processor is adapted to selectively adjust the operational parameters of the power saw machine for stopping the abnormal operating condition from continuously happening.

Abstract: A system and method for regulating the root mean square (RMS) voltage delivered to a load by an alternating current (AC) electrical circuit having a line voltage. To avoid radio frequency interference (RFI), the load is disconnected from the AC electrical circuit when energy stored in the load is at or near zero and is reconnected when the line voltage is at or near zero. Inductive loads are disconnected when the line current is at or near zero while capacitive loads are disconnected when the line voltage is at or near zero. The duration of the disconnection does not exceed one half-cycle of the fundamental frequency. Disconnections alternate between removing positive voltage half-cycles and negative voltage half-cycles to avoid a direct current (DC) bias. A system incorporating digital logic elements is provided for implementing the method and for detecting whether the load is inductive or capacitive.

Abstract: A circuit and method are proposed for constant on-time control for an interleaved multiphase voltage regulator, which monitor the channel currents of all the channels of the interleaved multiphase voltage regulator to select one from the channels to drive and so achieve interleaved phase operation.

Abstract: A control circuit for a switch unit of a clocked power supply receives an auxiliary signal from a resonant transformer driven by the switch unit and detects reference crossing moments when the auxiliary signal crosses a reference value. A driver is controllable to switch the switch unit, and a synchronization circuit synchronizes a turn-on of the switch unit within a predetermined time interval around a zero crossing of a voltage present across the switch unit, or of a current flowing through the switch unit. The synchronization circuit receives information about the reference crossing moments and provides a turn-on signal to the driver with a fixed phase delay at the reference crossing moments, so as to define turn-on moments at which the driver is to turn on the switch unit.

Abstract: Methods of reducing peak electrical demand at a single customer location of an electrical service provider during at least one time interval during a day can include shifting the activation of a first electrical appliance located at the single customer location from the at least one time interval during a day to a second time interval during which a second electrical appliance is not activated for at least part of the second time interval. Related systems, circuits, and computer program products are disclosed.

Abstract: A power supply system includes multiple power converter phases. A controller (e.g., a processor device) monitors energy delivery for each of multiple power converter phases that supply energy to a load. The controller analyzes the energy delivery associated with each of the multiple power converter phases to identify an imbalance of energy delivered by the multiple power converter phases to the load. Based on the analyzing and detection of an imbalance condition, the controller modifies a future order of activating the multiple power converter phases for powering the load. Accordingly, a single phase of a multiphase switching power converter may be prevented from becoming overloaded while delivering energy to power the load.

Abstract: Controlling input power is disclosed. In some embodiments, an in situ measurement of an operating condition in an operating environment is compared to a benchmark, and the comparison is used at least in part to determine whether to change input power.

Abstract: The invention involves a control circuit for a switch unit of a clocked power supply circuit, the switch unit being designed to effect input-side excitation of a resonant transformer arrangement, and comprises an input for receiving an auxiliary signal from the resonant transformer arrangement. The invention also includes a resonance converter that enables independent control of frequency and turn-on moments, or duty cycle, and thus enables a particularly efficient operation of the resonance converter, and a particularly precise regulation.

Abstract: An apparatus, system, and method is provided for reducing idle power in a power supply. The apparatus includes a connection module to determine whether a load is connected to the output terminal of the power supply. Also included is an idle module that turns off the power supply for an idle interval when the connection module determines that a load is not connected to the output. A monitor module turns on the power supply for a monitor interval when the idle interval ends. During the monitor interval, the connection module determines whether the load has been connected to the output terminal of the power supply. An activation module turns on the power supply if the connection module determines, during the monitor interval, that the load has been connected to the power supply. If the load has not been connected, another idle interval is initiated.

Abstract: Several techniques are provided to increase the efficiency and reduce the EMI of produced by a multiphase switching voltage regulator. According to one technique, a multiphase switching voltage regulator is controlled by varying in time the duration and/or position of each switching pulse for each of a plurality of channels of the switching voltage regulator in response to one or more signals representing a state of each of a plurality of channels of the voltage regulator. According to a second technique, a method is provided for controlling a multiphase switching voltage regulator comprising operating each channel of the voltage regulator at a different frequency. The timing of the switching pulses to each channel is scheduled to avoid time-overlap of switching pulses for two or more channels.

Abstract: To improve conversion efficiency at a DC-DC conversion time by providing driving units respectively for a plurality of switches and controlling the switches corresponding to a load current, an input voltage, an output voltage and an input/output voltage difference. When synchronously rectifying a plurality of first switches and a plurality of second switches by setting the first switches and the second switches alternately in an ON-state, the plurality of first switches are driven repeatedly in the ON- or OFF-state corresponding to a required output, the plurality of second switches are driven in the ON- or OFF-state in synchronization with the first switches, the driving of part of the plurality of first switches and part or all of the plurality of second switches is stopped corresponding to a load current value, an input voltage value, an output voltage value or an input/output voltage difference value.

Abstract: A motor control circuit for supplying power to a DC motor which drives a mechanism having a driven shaft, the control circuit having a parallel combination of a capacitor and switch in series with the DC motor. When the movement of the driven shaft is obstructed, the motor driver and the switch are synchronized in a manner to first charge the capacitor and then to reverse the voltage generated by the motor driver to momentarily double the voltage applied to the DC motor so that the increased torque of the DC motor is able to overcome the obstruction. The mechanism having a shaft driven by the DC motor may be, for example, an ETC valve or a window regulator.

Abstract: Systems, methods, and apparatuses are disclosed for determining dead-times in switched-mode DC-DC converters with synchronous rectifiers or other complementary switching devices. In one embodiment, for example, a controller for a DC-DC converter determines dead-times for switching devices of a synchronous rectifier or other complementary switching device of the converter in which a dead-time is derived from an output voltage or current that is already sensed and used in the output regulation of the converter. In another embodiment, a controller is provided for controlling a switched-mode DC-DC converter comprising a pair of power switches. The controller comprises an input, a reference generator, a comparator, a compensator, a dead-time sub-controller, and a modulator. In another embodiment, the controller may adjust the dead-times during the operation of the converter to adjust periodically and/or in response to changes in operating conditions.

Abstract: The methods and systems presented herein provide an improved means of correcting the variation of Voltage Output Differential (VOD) in differential drivers. In some embodiments, a high-precision reference voltage is generated not only based on a desired VOD, but also by monitoring the Voltage Common Mode (VCM) in a differential driver. In some embodiments, the VOD is then compared with the high-precision reference voltage to correct the output current. The result is a low-variation output voltage.

Abstract: A power factor controller for a switching power supply, that in one embodiment couples a power factor control circuit between an AC input and an output wherein a digital controller computes circuit currents for regulating the power supply without direct current measurements.

Abstract: An information handling system includes a power source configured to provide a plurality of power levels to a load. At least one of the plurality of power levels corresponds to a level obtained by de-rating a capacity of the power source from a nominal design specification of the power source.

Abstract: Manufacturing and/or operational variations that affect performance of an integrated circuit (IC) are at least partially compensated for, by determining the magnitude of these variations and providing one or more corresponding control signals to a voltage regulator, which, responsive thereto, increases or decreases the magnitude of the output voltage. The output voltage of the voltage regulator is typically provided to a power supply node of the IC. Similarly, the output of the voltage regulator may be provided to a substrate portion of the IC, so as to provide a substrate bias that is variable in response to changes in the performance of the IC.

Abstract: A boost quantity detecting section (103) detects a boost quantity of an inductor (L11). An operational amplifier (113) of a control section (106) compares the boost quantity detected by the boost quantity detecting section (103) with a reference voltage (ES12). When a supply voltage supplied from an AC power source (100) reduces and an output voltage is unchanged, the boost quantity detected by the boost quantity detecting section (103) increases. When a signal level of a boost quantity detection signal is higher than the reference voltage (ES12), a control section (106) reduces a target level of a switching current. The target level of the switching current decreases, so that the output voltage decreases and energy loss due to boosting reduces.

Abstract: A switched mode power supply comprises a first switch coupled to an input power source, a second switch coupled to ground, and an output filter coupled to a phase node defined between the first and second switches. The first and second switches are responsive to a pulse width modulated signal to thereby regulate power provided to the output filter. A controller is provided in a feedback loop that monitors operation of the first and second switches and delays activation of one of the first and second switches to preclude simultaneous conduction. The controller comprises at least one delay control circuit adapted to delay delivery of the pulse width modulated signal to at least one of the first and second switches. The delay control circuit detects a phase difference between state transitions of the first and second switches and provides a delay corresponding to a magnitude of the phase difference.

Abstract: A multipurpose transforming device includes a power supply device that has a power import device and a power output device respectively connected with two side of the power supply device. The power import device and the power output device have connectors used for connected with different types of plugs and outlets. The power output device has at least two output lines so as to supply power to several electric device loads. The power supply device includes an AC supply unit, a voltage-regulating unit, a galvanometry unit, a memory and a microprocessor. The AC supply unit transforms alternating current into direct current. The voltage-regulating unit regulates outputting voltage from zero to rated load according to the microprocessor control. The galvanometry unit samples real-time load current and transmits the sampling value to the microprocessor. A memory stores some common rated loads so that the microprocessor compares with sampling value until two groups of value matches.

Abstract: A multiple-phase DC—DC converter adds at least one additional phase to an N-phase DC—DC converter to improve the converter's response to changes in load. In one embodiment, an additional phase operates at a switching frequency greater than that of the N phases, to generate a current which is added to the N phase currents to improve the converter's response to changes in load. In another embodiment, an additional phase is configured to improve the converter's response to a load release. Here, the additional phase is kept off during load increase and steady-state conditions. However, when a load release occurs, the additional phase is turned on and acts to extract current from the converter's output terminal while the N phase currents slowly fall, to reduce the magnitude of output voltage overshoot that occurs on load release.

Abstract: A converter device is provided which has a power factor improving circuit that removes effects of noise superimposed on an AC power supply and reduces higher harmonics and improves the power factor. A power factor improving circuit (103) generally includes a voltage error amplifier (8), a current error amplifier (10), a comparator (11), a triangular wave oscillator (12), an output buffer (13), and a DC power supply (PS). A power factor improving unit (102) has a photocoupler (14) for detecting an output of an AC power supply (1) and a microcomputer (15), where the output (Vp) of the photocoupler (14) is given to the MCU of the microcomputer (15). A D/A converter (17) in the microcomputer (15) gives a converter output (DAO) to the power factor improving circuit (103) and the power factor improving circuit (103) gives a reference voltage (VREF) to the D/A converter (17).

Abstract: A motor control apparatus includes a fundamental wave current control system that controls a fundamental wave component of a motor current in an orthogonal coordinate system and a higher harmonic current control system that controls a higher harmonic component contained in the motor current in an orthogonal coordinate system. In the motor control apparatus, it is judged whether an output voltage from the power conversion device is in a saturated state, and a current control gain for the higher harmonic current control system is reduced if it is judged that the output voltage is in the saturated state.

Abstract: To balance the current of individual channel as well as regulate the output voltage for a multi-phase DC-to-DC buck converter, the converter output voltage is sensed and compared with a reference signal to produce a first error signal serving as first control signal for PWM signals of the converter and the channel currents are sensed, summed, averaged and subtracted to produce second error signals that are further modified by saw-tooth wave signal to produce second control signals for the PWM signals. Moreover, the reference signal is controlled by the summed channel currents for adjustable load regulation.

Abstract: A method of providing a regulated AC output voltage at a predetermined level that makes use of an AC input voltage having a higher level, includes the steps of rectifying the input voltage to provide a DC input reference voltage, rectifying the output voltage to provide a DC output reference voltage, comparing the DC output reference voltage to the DC input reference voltage to provide a comparator signal, providing a triac circuit connected to the AC input voltage that supplies the AC output voltage and using the comparator signal to control the triac circuit.

Abstract: A static series voltage regulator (SSVR) for an electric power distribution system protects a load on a feeder branch from voltage dips by boosting voltage under certain conditions. The SSVR contains a 3-phase voltage source inverter and a source bridge, fed from a source, supplying the dc side of the inverter. A series transformer is connected between the power source and a load coupling the inverter output to appear between the power source and the load. A surge filter connected in parallel with the series transformer protects the load from fast front voltage pulses produced by the inverter, and isolation and bypass switches isolate the inverter and series transformer from the power source and load. The inverter is controlled so that during normal operation it acts as a short on the series transformer, and, during a fault that causes a dip in the source voltage, it injects voltage in series with the source voltage to provide a boost action to maintain load voltage at a desired magnitude and balance.