Abstract: A DC/DC converter includes: a boost converter that boosts an input voltage in accordance with a first control signal; an insulated converter that converts an output of the boost converter in accordance with a second control signal; a current sensor that detects an output current of the insulated converter; a first controller that generates the first control signal based on an error between the output current detected by the current sensor and a first threshold value; and a second controller that generates the second control signal based on an error between the output current detected by the current sensor and a second threshold value that is larger than the first threshold value.

Abstract: A system and method are disclosed for controlling DC to AC power converters (inverters) that are operated as voltage sources and are paralleled on the AC side. This method allows for controlling frequency while sharing real power. The disclosed method requires no communication between inverters for proper load sharing, thus enhancing reliability of a system of parallel inverters. The only signals required for control are the AC voltage and frequency and their reaction to the inverter output current. The present invention allows a multiplicity of inverters or active rectifiers to share power in relation to their share of the available power capacity of the system. This makes it possible to parallel DG sources with various response times while they are connected to either a utility grid or in a stand-alone power network with no communications required between inverters. The addition of communications to the system allows the dispatch of energy for economic reasons and to fine tune load balance.

Abstract: Disclosed is a current mode switched power supply. The current mode switched power supply includes a switching element and a power stage coupled to the switching element and configured to provide, in response to the switching of the switching element, an output voltage and a feedback voltage related to the output voltage. The current mode switched power supply also includes a digital control circuit connected to the switching element to digitally control the switching of the switching element.

Abstract: A green-mode flyback pulse width modulation apparatus adopting a bipolar transistor structure IC process is used in a power supply. An oscillator circuit outputs a periodic clock signal to a control terminal of a power switch through an amplifier circuit for periodically turning on the power switch. A latch circuit is connected to the oscillator circuit, the amplifier circuit, the power switch and a feedback terminal of the power supply for periodically pulling down the potential at a control terminal of the power switch in response to a feedback signal generated by the feedback terminal to turn off the power switch and continue suspending the operation of the oscillator circuit when the power supply is at a light load, and will resume the output of the oscillator circuit till the potential of the feedback signal potential drops, so as to achieve the green-mode function.

Abstract: A power supply apparatus for electric operation is provided for an electric operation apparatus, and includes an instructing signal input portion which generates a DC output voltage to a high-frequency generating circuit that generates a high frequency and which receives an instructing signal for controlling the output voltage. The instructing signal input portion includes at least a noise reducing circuit which reduces a normal-mode noise.

Abstract: A system for controlling a soft start for a switching converter includes a digital feedback control system for receiving an analog voltage signal representing the output of a switching converter, for digitally processing the analog voltage signal by comparing it to a corrected reference voltage to generate a voltage error signal and for generating drive signals to control the operation of the switching converter to provide a regulated output. A microcontroller provides a secondary feedback loop for generating the corrected reference voltage. The secondary feedback loop enabling the output voltage signal to vary linearly over time during a soft start.

Abstract: In the PWM circuit of the present invention, a PWM counter counts clock signals. A reference value setting register sets a comparative reference value for determining a duty ratio of a PWM signal. A comparator generates the PWM signals based on a comparative result of the comparative reference value and a count value of the PWM counter. A delay device delays the PWM signal. A switching device switchably outputs the output of the comparator and the output of the delay device in order of time sequence. Thereby, the pulse phase of the PWM signal can be adjusted.

Abstract: This invention provides a power conversion circuit control apparatus which rapidly detects the voltage amplitude and phase of each phase, corrects the output of a current controller by the mean voltage amplitude and mean phase, and corrects, on the basis of the voltage amplitude and phase of each phase, a voltage amplitude command and voltage phase command to be applied to pulse width modulation. The apparatus can suppress an overcurrent even when the AC voltage is unbalanced, and restart the operation without generating any overcurrent when the circuit is to be reactivated.

Abstract: A pulse modulation power converter comprising a forward path including a forward block (15), a switching stage (11) for amplifying an output from the forward block, and an output filter (12) for low pass filtering an output signal from the switching stage, a global feedback path (13), connected to the low pass filtered output signal, comprising a global feedback block (18, 19) for generating a feedback signal, and means (14) for subtracting said feedback signal from an input signal, and feeding the result to said forward path. The global feedback block and/or forward block includes means for compensating at least a portion of a phase lag of said output filter, and means for obtaining a 180 degrees phase lag at a switching frequency, thereby achieving conditions for a controlled oscillation at said switching frequency. The control system combines the advantages of the self-oscillation technology with a high gain, wide-band control loop for suppressing non-linearities.

Abstract: Methods and apparatus are disclosed for converting DC power to AC and for driving multiple discharge lamps and, more particularly, Cold Cathode Fluorescent Lamps (CCFLs), External Electrode Fluorescent Lamps (EEFLs), and Flat Fluorescent Lamps (FFLs). Disclosed methods, among other advantages, allow accurate current sharing among the lamps, minimization of the total number of power switches, and, in general, simplification of the complexity of the control system.

Abstract: In a DC to DC converter, a transformer circuit includes a primary winding and a secondary winding member composed of series-connected first to fourth secondary windings having one and the other ends. The one and the other ends of the series-connected first to fourth secondary windings are connected to a first output terminal. The first and second secondary windings are wound around a first magnetic path in opposite directions, and the third and fourth secondary windings are wound around a second magnetic path in opposite directions. A first rectifying element is connected between the second output terminal and a connection point between the first and second secondary windings. A second rectifying element is connected between the second output terminal and a connection point between the third and fourth secondary windings.

Abstract: Methods and apparatus are provided for compensating for a deviation in voltage output of a phase leg inverter when dead-time periods are inserted to prevent shoot-through failures. The method includes determining a pulse width for an input signal to the inverter such that the inverter voltage output is a desired amount. The pulse width is based on the non-inverted or inverted pulse sequences of two carrier signals and the polarity of current through the inverter. An amount of pulse width is added to the input signal when the current is positive, and an amount of pulse width is subtracted from the input signal when the current is negative. An additional amount of pulse width is added to or subtracted from the input signal depending on whether the carrier signal sequence changes from a non-inverted signal to an inverted signal or changes from an inverted signal to a non-inverted signal, respectively.

Abstract: A method of designing a random pulse width modulation (RPWM) inverter with unwanted harmonic elimination, which first uses a Fourier analysis and a numerical analysis to eliminate the unwanted harmonic components, next uses the equal area approach to produce switching angles to be used as start values for solving non-linear equations, next selects low-order harmonics to be eliminated and randomly sampled harmonics to solve the equations and obtain pluralities of switching angles for eliminating different harmonics, next applies pluralities of harmonics to a random probability function to thereby obtain a harmonic distribution, and finally uses a random sampling to evenly disperse the higher side-band harmonic components and effectively suppress the low-order harmonic components.

Abstract: A backlight inverter using electromagnetic induction and full-wave rectification at a second side of a main transformer includes a drive unit for generating a first voltage and a main transformer having first and second coils. The main transformer converts the first voltage from the drive unit into a second voltage, and outputs an AC current of the second voltage to both ends of a lamp. An auxiliary transformer has a first auxiliary coil formed on a current line connecting between the second coil of the main transformer and the lamp and a second auxiliary coil inductively coupled with the first auxiliary coil. The auxiliary transformer detects the current flowing to the lamp. A full-wave rectifier rectifies the current detected by the auxiliary transformer, and a drive controller controls the PWM duty of the first voltage based on a voltage from the full-wave rectifier.

Abstract: To provide a switching power supply apparatus which can achieve the followings simultaneously in high levels: the voltage waveform capable of reducing switching noise to the least is in a sine-waveform; capable of providing an output of stable voltage without a control, and a simple response; and capable of corresponding to instantaneous peak current without having saturation of the core. It relates to an improvement of a resonance-type Royer converter with less switching noise as a base, which is directed to be used for audio equipment. A second inductor is inserted to the primary side inductor between a rectifier circuit and a smoothing means, which is coupled to the primary-side inductor in a same magnetic circuit in a direction of canceling a DC magnetic flux. Moreover, timing of the next cycle is determined by applying a center tap voltage of a transformer to a synchronous signal input terminal of a control IC. Thereby, a self-excited oscillating action is actually stabled.

Abstract: A switching device and a method of operating a switching power element are disclosed for generating a train of drive pulses (D1 to D32) in a basic pattern for a repetition cycle time (T to TF) having leading time intervals (Th1 to Th3, Th1? to Th3?), associated with leading edges (a1 to a32) of the drive pulses, and trailing time intervals (Tl1 to Tl3, Tl1? to Tl3?), associated with trailing edges (b1 to b32) of the drive pulses, which are different from each other, whereby switching frequencies and associated harmonics, resulting from the leading edges and the trailing edges of the drive pulses, are diffused. A diffusion frequency, representing an inverse number of the repetition cycle time for the basic pattern is set to be higher than an audible frequency.

Abstract: A quasi average current mode control scheme is provided. The control scheme allows only detecting one part of the inductor current of the switching converter to control the inductor current and make the average current of the inductor follow the reference current. The control scheme is noise insensitive and makes the whole controlled system cost effective.

Abstract: A closed loop power converter circuit of a UPS or other power supply includes a pulse width modulator circuit in a forward path of the closed loop power circuit. A compensation circuit provides pulse width commands to the pulse width modulator at a first rate. A feedback circuit digitally filters samples of an output of the closed loop power converter at a second rate greater the first rate and that provides the filtered samples to the compensation circuit. In some embodiments, the compensation circuit may be operative to compensate for the phase lag associated with a low pass output filter.

Abstract: A pulse width modulation inverter circuit is provided. The circuit includes a power switch driver, a power switch, a transformer unit, a feedback detector unit, and a voltage control oscillator. The circuit is electrically coupled to the DC power source to drive a load. The circuit adjusts the pulse width of the signal outputted from the power switch driver according to the voltage inputted to the DC power source. Accordingly, the circuit can maintain a fixed input voltage received by the fluorescent tube. Thus, the high input voltage but low output phenomenon can be avoided.

Abstract: A cellular inverter generates an alternating output voltage by a succession of serial combinations of DC voltage electrical sources that are available to it within switchable cells and, within a serial combination currently in use, by a voltage regulation using high-frequency chopping. This voltage regulation exhibits a certain lag and allows through an undesirable voltage step during the repositioning of its operating range caused by a change of the serial combination currently in use. The cellular inverter proposed comprises, in its high-frequency switch-mode voltage regulation circuit illustrated in the figure, a pre-compensation circuit that allows the lag to be compensated for and this undesirable voltage step to be considerably attenuated.

Abstract: An apparatus for controlling a voltage source converter with at least two bridges of semiconducting self commutating elements connected in anti-parallel with a diode, including circuitry for producing a switching control pulse train to form a fundamental frequency, circuitry for effecting a switching order and circuitry for detecting a switching event.

Abstract: In a method and system for an improved inverter providing power to a load, the inverter receives a direct current (DC) input. A plurality of switches included in the inverter are controlled by a plurality of control signals to generate an alternating current (AC) output in response to the DC input. A zero crossing of the AC output current provided by the plurality of switches is detected, and the controlling of the plurality of switches is delayed in response to the zero crossing. The amount of delay is adjusted responsive to a change in the DC input to effectively maintain a constant switching frequency of the inverter. The delayed AC output current of the plurality of switches is filtered to provide power to the load.

Abstract: A PWM motor speed control circuit (10) includes a PWM signal generator (20), a driver integrated circuit (IC) (101) and a photocoupler (30) coupled between the PWM signal generator and the driver IC. The photocoupler receives an original PWM signal generated by the PWM signal generator and outputs a new PWM signal in response to the original PWM signal, wherein a voltage parameter of the original PWM signal is isolated by the photocoupler from a voltage parameter of the new PWM signal. The new PWM signal is fed to the driver IC and used for controlling speed of a motor (100).

Abstract: A combination controller incorporates features of a classic controller and a state space controller to function as a hybrid controller unit. The PID portion of the classic controller regulates the steady state error and is separated from the pulse width modulated constant frequency signal generator that also comprises part of the classic controller. The PID portion is coupled with a state space controller such that the output of the PID controller, i.e., the steady state error correction, is input to the state space controller. The state space controller further receives as input variables a reference sinusoidal signal, the load current, the current across a pre-load filter capacitor, and the output voltage. From these inputs, the state space controller employs principles of differential calculus to generate a transient error correction that is fed to a PWM signal generator for generating a sinusoidal output voltage signal with both steady state and transient error correction.

Abstract: A switching controller having frequency hopping is used for reducing the EMI of a power supply. A pattern generator generates a digital pattern code in response to a clock signal. An oscillator generates an oscillation signal for determining a switching frequency of a switching signal. A programmable capacitor coupled to the oscillator modulates the switching frequency in response to the variation of the digital pattern code. An attenuator connected to a voltage feedback loop attenuates a feedback signal. The feedback signal controls the pulse width of the switching signal. A programmable resistor coupled to the attenuator determines an attenuation rate of the attenuator in response to the digital pattern code. The attenuation rate is increased as the switching frequency increases. The pulse width of the switching signal is thus reduced, which compensates the decrease of the switching period and keeps the output power and the output voltage constant.

Abstract: A double-ended inverter system for a vehicle having a load, a first energy source, and a first inverter system coupled to the first energy source and adapted to drive the load. The double-ended inverter system further having a secondary energy source, a second capacitor coupled in parallel to the secondary energy source, and a second inverter system coupled to the secondary energy source and adapted to drive the load. A controller includes an output coupled to the first inverter system and the second inverter system for providing at least one pulse width modulated signal to the first inverter system and the second inverter system.

Abstract: A circuit and method of dithering the switching frequency of an off-line power factor corrected (PFC) pre-regulator. The circuitry used to dither the frequency is advantageously accomplished by taking advantage of the PWM's internal timing circuitry. This invention reduces narrow band EMI and eliminates the need to provide specialty PWM controllers to achieve dithering.

Abstract: A switched mode power supply having a regulated reflected voltage. In one circuit, a power switch is coupled between first and second electrical terminals. An energy transfer element is coupled to the first electrical terminal of the power switch. A power supply rail is coupled to the second electrical terminal. A control circuit is coupled to the energy transfer element and to the power switch. The control circuit is to switch the power switch in response to a signal derived from a voltage at the energy transfer element to regulate an output of the circuit.

Abstract: A method for determining output currents of a three-phase frequency converter comprising a voltage intermediate circuit and three power switch pairs constituting an output of the frequency converter, wherein the power switches constituting a pair are coupled in series between a positive and a negative busbar of the voltage intermediate circuit so that a midpoint of each switch pair constitutes a phase output of the frequency converter.

Abstract: This invention relates to a method of operating a bridge circuit comprising an input that receives a DC signal of voltage +VS, an output having an electromagnet connected thereacross, first and second arms having first and second switches respectively and being connected to opposed ends of the electromagnet. The method comprises the steps of receiving a voltage demand signal indicative of a desired voltage to be supplied to the electromagnet in a period and generating first and second switching signals with reference to the voltage demand signal. The first and second switching signals are then applied to the first and second switches respectively during the period thereby causing the switches to switch between on and off states to produce voltages across the electromagnet pulsed at levels of +VS, 0V and ?VS, such that the average voltage across the electromagnet during the period is substantially equal to the desired voltage.

Abstract: A switching frequency jitter having output ripple cancel includes a pattern generator generating a pattern code in response to a clock signal. An oscillator generates an oscillation signal for determining a switching frequency of a switching signal in response to the variation of the pattern code. An attenuator is connected to a voltage feedback loop for attenuating a feedback signal. The feedback signal is utilized to control the pulse width of the switching signal. A programmable resistor is connected to the attenuator for programming an attenuation rate of the attenuator in response to the pattern code. The attenuation rate is increased whenever the switching frequency increases. The pulse width of the switching signal is thus reduced, which compensates the decrease of the switching period and keeps the output power and the output voltage of the power supply constant.

Abstract: Proportional-delayed zero-crossing frequency-drift estimator devices are provided. Given N-number of time samples, the current zero-crossing time estimation technique uses only two zero-crossing time samples for repetition-rate estimation. The term “zero-crossing point” refers to the point where a sinusoidal waveform varies from a positive to a negative value and crosses the zero value in the process. The proportional-delayed zero-crossing frequency-drift estimator devices employ four zero-crossing time samples by utilizing both proportional zero-crossing points for current information and delayed zero-crossing points for past information so that the noises in the time samples will be smoothed out making a less noisy estimation.

Abstract: A switch mode power supply has pulse width modulation (PWM) frequency dithering of a PWM clock frequency. The PWM frequency dithering circuit may change the frequency of the PWM clock based upon each of a plurality of frequencies. A PWM time base circuit may comprise a period register containing a PWM period value, a comparator, and a PWM counter, wherein a PWM count value may be incremented in the PWM counter by the variable frequency PWM clock, the comparator may compare the PWM period value with the PWM count value and when the PWM period value and the PWM count value are substantially equal the PWM count value may be reset.

Abstract: A PTTM (Pulse Transition Time Modulation) power converter includes an input terminal supplied by a PWM (Pulse Width Modulated) signal, a PWM to PTTM converter, a controlled capacitance proportional to the pulse transition time, a pulse amplifier driving a power transformer, a gate drive transformer, and synchronous rectification means. The output voltage can be kept constant by varying the pulse transition time to cancel the effect of fluctuation of the operating voltage or variation of the load.

Abstract: An auto-switching converter with PWM and PFM selection supplies a boosted DC power to a load through a power switch unit. A starter outputs a starting-enabling signal. An auto PWM/PFM controller is connected to the starter for outputting a selection signal. A controller and a PFM controller are connected to the auto PWM/PFM controller, the power switch unit and the load for transmitting a PWM control signal and a PFM control signal to the power switch unit, respectively, for controlling the switching action of the power switch unit.

Abstract: The disclosure concerns a a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area, in order to enable quick acceleration and deceleration. A controller comprises a voltage saturation detecting apparatus for detecting the voltage saturation of the output voltage of an inverter circuit, based on the battery voltage, and a waveform controller that converts the drive waveform of the inverter circuit into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWN carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation detected by a voltage saturation detecting means. This arrangement allows the controller to continuously change the drive waveform of the inverter circuit.

Abstract: There is provided an adjustable integral component in a feedback loop of a closed loop control system. The closed loop control system controls an output signal of an electric generator. The adjustable integral component provides an integral signal. The integral signal is proportional to the output signal in a first operational mode. The integral signal is proportional to a time integral of an output signal in a second operational mode. According to another aspect of the invention there is provided a non-linear component in a feedback loop of a closed loop control system. The closed loop control system controls an output signal of an electric generator. The electric generator having non-linear characteristics. The feedback loop has an error signal, of which the output signal is responsive to. The non-linear component receives a load signal and provides a non-linear signal related to the non-linear characteristics of the electric generator. The error signal is responsive to the non-linear signal.

Abstract: A method of providing a unified power control of a motor including providing a first inverter system, a second inverter system, and a motor coupled therebetween; coupling the first inverter system coupled to a first energy source; coupling the second inverter system coupled to a secondary energy source; generating a first pulse width modulated signal; and generating a second pulse width modulated signal. The first inverter system and the second inverter system are driven with the first pulse width modulated signal and the second pulse width modulated signal respectively in order to control a fundamental component of an output voltage of the first inverter system and the second inverter system to control the motor.

Abstract: A control circuit is described in which a single input terminal receives digital control signals and analog control signals. In accordance with the principles of the invention, the control circuit includes an automatic power down circuit to place the control circuit into a low power draw or “sleep” mode whenever predetermined conditions are present. The automatic power down circuit monitors the single input terminal and when no demand for motor operation occurs for a predetermined period of time, the automatic power down circuit operates to place the control circuit into the low power draw mode.

Abstract: A method and a circuit for controlling a switching frequency signal used in a direct current to direct current (DC to DC) converter are proposed. The DC to DC converter generates an output voltage to drive a system. The switching frequency signal is generated by inputting a modulation frequency to a pulse width modulation (PWM) circuit. The method includes steps of: 1. generating a control signal from the system to stop the pulse width modulation (PWM) circuit to generate the switching frequency signal when a signal is received by the system; and 2. restarting the pulse width modulation (PWM) circuit to generate the switching frequency signal in order to increase the output voltage to drive the system when the output voltage from the DC to DC converter is under a predetermined voltage.

Abstract: A pulsating current inverter control circuit aims to convert AC power provided by an external electric source to a pulsating current through a rectification unit. The inverter has a control unit which outputs an operation frequency to an actuation unit to divide the pulsating current to a plurality of electric pulse waves to drive a transformer to perform voltage transformation and drive a load. The invention further includes an inspection unit which has a preset reference electricity value to compare with the pulsating current and output an activation signal and a deactivation signal to activate or deactivate the actuation unit so that the transformer stops performing voltage transformation while the actuation unit is deactivated. Thus the transformer can output power to drive the load as desired.

Abstract: An improved motor controller for driving polyphase alternating current dynamoelectric machines from a direct current power source that employs two inverter bridges controlled with a state vector modulation symmetrical state sequence that has a desired “chop” frequency so that each of their outputs produce a fundamental component that is exactly in phase but chop frequency components that are exactly 180 degrees out of phase with each other, with their outputs combined through respective interphase transformers to average the potentials of the chop frequency components.

Abstract: Methods and apparatus for canceling dead time effects in the form of common mode voltages produced by a three-phase power conversion device in a rectifier/inverter variable frequency drive (VFD) system includes limiting the voltage difference between phase voltages at certain switching transition times to an amount ?, that is a function of the dead time that is specified for the switches and delaying gating signals to the switches to remove unexpected pulses produced by common mode voltages.

Abstract: The present invention relates to a control circuit for controlling the output power of a primary-controlled switched mode power supply unit, which comprises a primary switch and a transformer with an auxiliary winding. Within the auxiliary winding, voltage pulses are induced by primary-sided switching operations, which can be taken into account when controlling the output power. In order to provide an improved control and an enhanced flexibility with respect to the operational parameters, the sampling instance is determined based on the duration of the voltage pulse at the auxiliary winding during a previous switching cycle. In order to detect a defective contact between the auxiliary winding and the control circuit in a particularly simple and secure manner, the negative voltage pulse at the auxiliary winding occurring when the switch is closed may be used for confirming a proper connection.

Abstract: A technique for reconstructing phase currents based on measurements of a DC bus current. Non-observable regions of DC bus current samples to reconstruct phase currents are reduced in size by using two phase space vector modulation. The non-observable regions can be further reduced by omitting deadtime insertions for switch actuations when output current is higher than a given threshold. Voltage command vectors in non-observable areas can be constructed by two time averaged vectors one of which is constructed to obtain an observable DC bus current reflecting motor phase current. The additive vectors have the same combined time average value as that of the voltage command vector in order to preserve volt-seconds. Current samples may also be averaged to provide a more accurate reconstruction of phase current. Current samples are time delayed to avoid transients for more accurate readings.

Abstract: System and method for protecting a power converter. The system includes a compensation system configured to receive an input signal and generate a control signal, a cycle threshold generator configured to receive the control signal and generate a cycle threshold, and a comparator configured to receive the cycle threshold and a feedback signal and generate a comparison signal. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and control an input current for a power converter. The input current is associated with an output power for the power converter. The cycle threshold corresponds to a threshold power level for the output power. The threshold power level is constant, decreases, or increases with respect to the input signal.

Abstract: An active filtration or harmonic scrubber system for power systems that convert AC power on an AC bus to DC power that cancels or reduces harmonic current injected by nonlinear loads onto the AC bus using high-bandwidth pulse width modulation (PWM) inverters.

Abstract: A method is described of regulating the instantaneous electromagnetic torque of a polyphase rotating electrical machine equipped with stator and/or rotor windings supplied by a voltage and a current generated by an inverter formed of switches whose switching is controllable. The method comprises a step of commanding the switching of the switches of the inverter using the fundamental frequency of the voltage generated by the inverter and a form of synchronous pulse width modulation configured as a function of an input set point, and a step of calculating the input set point from an instantaneous torque set point at each regulation time. The method further comprises a step of determining the time interval between two successive regulation times so that the time interval corresponds to an integer multiple of the period of oscillation of the instantaneous torque of the machine.

Abstract: The present invention pertains to a method of determining a working voltage of an inverter, which utilizes a rectifying method to transform an alternating current into a pulse direct current, and then via a working frequency, divides a direct current cycle, which ranges in a lowest voltage–highest voltage–lowest voltage manner, into multiple continuous voltage pulses. The inverter receives each one of the multiple continuous voltage pulses and acts in response to each one of the multiple continuous voltage pulses and corresponding to the voltage cycle ranging between the lowest voltage and the highest voltage to output a variable voltage signal to a load. Thus, the working voltage of the inverter is analogous to the input voltage of the alternating current, and a power-factor regulating effect can be accomplished directly by the inverter.

Abstract: A PWM system that minimizes output ripple of a multiphase DC-DC converter which converts N input voltages including at least one dissimilar input voltage. The PWM system includes PWM waveform logic that generates N PWM signals including a PWM signal for each of the N input voltages, and PWM control logic that optimizes relative phases of the N PWM signals based on voltage levels of the N input voltages. Various circuits and/or methods are contemplated for optimizing phase, including, for example, centering pulses for each PWM cycle, distributing pulses based on predetermined optimal phase angles, determining input voltage levels and selecting predetermined optimal phase angles, generating phase signals employing predetermined phase angles, measuring input voltages and calculating optimal phase angles, and using PLL logic or the like to measure and equalize off-times between PWM pulses.