Abstract: An auxiliary circuit for reducing low order current harmonics in a three-phase drive system driving a single-phase load, the three-phase drive system including a three-phase source voltage connected to a rectifier system connected to a DC link choke inductor connected to a three-phase current source inverter system.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: The control device of an electric power converter comprises a control device controlling turn-on of semi-conductor legs. The converter comprises DC voltage supply lines, an inverter connected between said lines and outputs. The control device comprises a processing unit to supply modulation signals of control signals of said inverter legs. The control device comprises a module for determining a general control component. The module for determining detects a detection signal representative of a highest current signal in absolute value. The detection signal is used to select a modulation signal on which an over-modulation is applied via the general control component. In the method, the detection signal is used to determine a general control component.

Abstract: A high power supply to control an abnormal load includes a high voltage power processor to amplify a supplied DC power and to output the amplified DC power, a trans/rectifier to transform the DC power to a high voltage power and to rectify the high voltage power, a load detector to compare a load voltage output from a load with a predetermined reference voltage and to output a comparison voltage to detect the abnormal load of the load, and a high voltage controller to supply a chip enable signal to the high voltage power processor to interrupt the high voltage power processor when the comparison voltage output from the load detector is smaller than a predetermined reference value that is set to correspond to a minimum load of the load. Therefore, a user and peripheral components an image forming apparatus are protected from electric shock and being damaged by interrupting an output of the high voltage according to the abnormal load.

Abstract: The control device of an electric power converter comprises a control device controlling turn-on of semi-conductor legs. The converter comprises DC voltage power supply lines on three levels with two filtering capacitors. The control device supplies modulation signals of control signals of said legs. The control device comprises a regulating circuit to regulate the voltage variation of intermediate voltage via a general control component. The general control component is determined according to modulation signals, to signals representative of DC voltage and to signals representative of currents to take part in regulation of the intermediate voltage. The method processes voltage variation regulation via the general control component.

Abstract: A current limit signal having a multi-slope waveform is provided for a power converter that has a power switch switched to convert an input voltage to an output voltage, for output power control more preciously. The current flowing through the power switch has a maximum value being a function of a duty cycle of the power switch when the power converter operates at a constant output power condition. The current limit signal is generated according to the function, and is compared with a sensing signal produced from the current flowing through the power switch, so as to turn off the power switch if the sensing signal is not lower than the current limit signal.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: An electric power converter with a control device that comprises a processing unit receives control signals and sends modulated signals to inverter stages of the electric power converter. The control device also controls a common stage of the electronic power converter, which is connected between power lines and a common neutral connection. The signals to the common stage are outputted based on inputs from a modulation signal and a reference voltage signal.

Abstract: A coordination control device of a power output apparatus includes a coordination control unit. The coordination control unit calculates an intermediate value between the maximum value and minimum value among voltage controls for a first motor generator, and voltage control from an AC voltage control generation unit to generate an AC voltage across neutral points of first and second motor generators, and outputs a value that is each phase voltage control for the first and second motor generators minus the calculated intermediate value to a signal generation unit as the final voltage control for the first and second motor generators.

Abstract: System and method for providing control for switch-mode power supply. According to an embodiment, the present invention provides a system for regulating a power converter. The system comprises a signal processing component that is configured to receive a first voltage and a second voltage, to process information associated with the first voltage and the second voltage, to determine a signal based on at least information associated with the first voltage and the second voltage, and to send the signal to a switch for a power converter. The switch is regulated based on at least information associated with the signal. The signal processing component is further configured to determine the signal to be associated a first mode, if the first voltage is higher than a first threshold.

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: A pulse width modulation method has the steps of operating a second instruction signal so that each of the differences between two or three arbitrary instruction signals in three first instruction signals may become more than the predetermined value, and modulating in pulse width based on the second instruction signal.

Abstract: An inverter providing power to a load, the inverter receiving 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 may be filtered to provide power to the load.

Abstract: A universal input voltage device is presented which may receive a wide range of regulated and unregulated input voltages, both DC and a wide range of variable frequency AC, and output a desired regulated current at a desired voltage independent of the fluctuation of input voltage and frequency. The circuit includes a preconditioning input circuit, a Buck converter circuit with over voltage protection, flyback and boost circuits, and a shutdown circuit configured to drive a predetermined electrical or electronic device.

Abstract: The present invention previously sets a threshold voltage, compares the set threshold voltage with a reference voltage, and judges whether a minimal pulse width of a PWM signal is obtained. When a pulse width of one PWM signal is equal to or greater than the minimal pulse width, but each pulse width of two PWM signals is less than the minimal pulse width, a sine wave voltage corresponding to one of the two PWM signals less than the minimal pulse width is varied to a threshold voltage to detect two phase currents, and a remaining one phase current is calculated based on the two detected phase currents. After the phase current was detected by varying the threshold voltage, a level difference between an original sine wave voltage and the threshold voltage is set as a compensation voltage, and the sine wave voltage is compensated by the compensation voltage.

Abstract: A modularized active power filter includes a control module and at least one power module. The control module automatically identifies the number of the parallel connected power modules and generates one set of PWM signals to correspondingly control the parallel connected power modules, so as to provide a final compensation current by single power module or plural power modules. Thereby, the compensation demand of a load is met. Consequently, the modularized active power filter is able to improve the flexibility of compensation capacity, shorten the time for service, be suitable for mass production, and lower the manufacturing cost.

Abstract: A control apparatus for controlling a three- or single-phase semiconductor power converter employing fixed-pulse switching patterns superposes a DC component on an AC output voltage, to suppress asymmetrical magnetization of a transformer connected to the power converter. The three-phase semiconductor power converter 1 provides an AC output. The voltage of the AC output is changed by the transformer 12.

Abstract: Methods and apparatus are provided for reducing voltage distortion effects at low speed operation in electric drives. The method comprises receiving a first signal having a duty cycle with a range between minimum and maximum achievable duty cycles, producing a second duty cycle based on the minimum achievable duty cycle if the duty cycle is within a distortion range and less than a first clipping value, producing a second duty cycle based on the closer of minimum and maximum pulse widths if the duty cycle is within the distortion range and between the first and a second clipping value, producing a second duty cycle based on the maximum achievable duty cycle if the duty cycle is within the distortion range and greater than the second clipping value, and transmitting a second signal to the voltage source inverter having the second duty cycle.

Abstract: Disclosed is an electric circuit, in particular for a medium voltage power converter. The circuit has at least four semiconductor switches which form a series connection and which are connected to poles of a direct current voltage (Ud). A diode is connected in parallel in an inverse direction to each semiconductor switch. A capacitor is connected in parallel to the two semiconductors in the middle of the series connection. The circuit is provided with a pole of an output potential (Ua) which is connected centrally in the series connection. The circuit has a control device for successively controlling the semiconductor switches. The time interval between the transition of two of the semiconductor switches into their respective controlling states is minimal.

Abstract: A solid state reversing AC motor starter that employs a DC power source and a power bridge employing insulated gate bipolar transistors that provide an ungrounded three phase AC output. The AC output is connected to the power input of the motor starter, which requires simultaneous RUN and Directional Commands to initiate valve actuation.

Abstract: A universal alternating current (AC) inverter system with galvanic isolation takes an unregulated direct current (DC) input and provides a high-quality AC output that may be used in conjunction with both linear and non-linear loads. The universal AC inverter system includes a DC-DC converter for converting an unregulated DC input to a regulated DC output, and a DC-AC inverter for converting the regulated DC output to a high-quality AC output. The DC-DC converter includes a DC link isolation high frequency transformer that provides galvanic isolation between the unregulated DC input and the AC output. To avoid saturation of the transformer, the controller for the DC-DC converter employs a DC offset correction loop that prevents accumulation of DC content on the primary side of the transformer. The universal AC inverter system includes a 4-phase inverter topology that converts the regulated DC voltage provided by the DC-DC converter to an AC output.

Abstract: An adaptive pulse positioning system for a voltage converter providing an output voltage, the system including a PWM generation circuit, a sensor, and a pulse positioning circuit. The PWM generation circuit generates a PWM signal with PWM pulses for controlling the output voltage of the voltage controller. The sensor senses an output load condition of the voltage converter and provides a load signal indicative thereof. The pulse positioning circuit adaptively positions the PWM pulses based on the load signal. A method of adaptively positioning PWM pulses that are used to control an output voltage of a voltage regulator including generating a series of PWM pulses based on a clock signal, sensing an output load condition, and adaptively shifting the series of PWM pulses based on the output load condition.

Abstract: A power system for providing an output power to a load is provided. The system comprises a generator configured to generate an alternating current input power and an power converter system coupled to the generator and configured to generate an output power and provide the output power to the load through at least one transformer. The system further comprises a converter control system coupled to the converter system and configured to drive the converter system in an interleaved pattern to reduce harmonic components in the output power and the alternating current input power.

Abstract: Method and system are provided for controlling an alternating current (AC) motor via an inverter. The method includes selecting a pulse sequencing method based on a modulation index of the inverter, and providing a voltage to the AC motor based on the pulse sequencing method. The system includes an inverter having a modulation index (Mi) and a controller coupled to the inverter. The controller selects a pulse sequencing method based on Mi and produces a signal based on the pulse sequencing method. The inverter includes a switch network producing a voltage in response to the signal, and the voltage drives the AC motor.

Abstract: A controller applies a pattern of pulses to switching elements within a multi-level controller to effectuate control of the fundamental voltage magnitude and phase associated with the converter, as well as providing harmonic minimization of the 5th and 7th level harmonics. The controller combines a first pattern of pulses with a second pattern of pulses phase shifted by an amount based on the desired fundamental voltage magnitude to create a third pattern of pulses. The controller applies a phase shift to the third pattern of pulses based on the desired fundamental voltage phase. The controller supplies switching control waveforms to active components within the multi-level controller based on the phase shifted third pattern of pulses such that the desired fundamental voltage magnitude and phase is generated and selected harmonics are minimized.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: An apparatus for controlling a power converter including a voltage-vector control unit that determines, based on voltage instruction value for the power converter, a voltage vector output from a power converter in one control cycle of pulse width modulation control and times for outputting of the voltage vector, a voltage-vector adjusting unit that adjusts the time of outputting of the voltage vector so that time of outputting of a zero-voltage vector is larger than a fixed time or zero, and a firing-pulse generating unit that generates a signal for turning on and off a semiconductor switching element included in the power converter, based on the time of outputting of the voltage vector adjusted by the voltage-vector adjusting unit.

Abstract: A method is disclosed for generating pulse width modulated pulse control signals for controlling switches in a switching power supply. First, a count value is determined of a master clock within a switching cycle of the power supply from beginning to end thereof. A separate state machine providing for each edge in each of pulse control signals and each is operated to generate the associated edge as a function of the sum of a fixed reference count value from the beginning of the switching cycle and a determined count value when the sum is determined to equal the actual count value.

Abstract: An active power filter comprises an energy storage capacitor, an inverter, a filtering circuit and a controller. The inverter is controlled to act as a virtual resister at a fundamental frequency for compensating for the power loss of the active power filter, act as a virtual capacitor at a fundamental frequency for compensating for a fundamental reactive power of the load, and/or generate a harmonic current for suppressing the harmonic currents of specific orders of the load.

Abstract: A method and apparatus for a spread-spectrum oscillator for a switched power converter is provided. The spread-spectrum oscillator includes a current waveform generation circuit, a capacitor, a switch, and a comparator. The capacitor is arranged to receive an oscillator current to provide a ramp voltage. The comparator is arranged to compare the ramp voltage with a reference voltage to provide an oscillator voltage. Further, the switch is arranged to discharge the capacitor when the oscillator voltage is asserted. The current waveform generation is arranged to, if enabled, provide at least a portion of the oscillator current as a triangle wave, or other type of modulating waveform suitable for spread-spectrum. Accordingly, the oscillator voltage is a spread-spectrum signal.

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 control system and a method of using the same for an electric machine having a random number generating module generating a random number ranging from a first value to a second value, a multiplying module multiplying the random number and a sample rate to generate an random delay value; and a delay limiter module limiting the random delay value as a function of speed of the electric machine and generating a limited delay value.

Abstract: A switching controller for a parallel power supply is disclosed. The switching controller includes an input circuit coupled to an input terminal to receive an input signal for generating a phase-shift signal, a first integration circuit coupled to the input circuit to generate a first integration signal in response to a pulse width of the input signal, and a control circuit coupled to the first integration circuit to generate a switching signal for switching the power supply, the switching signal being enabled in response to the phase-shift signal, a pulse width of the switching signal being determined in accordance with the first integration signal.

Abstract: A method and apparatus for reducing common mode noise in a three phase pulse width modulated (PWM) system the method comprising the steps of receiving modulating waveforms, identifying a first of the modulating waveforms that is instantaneously the maximum of the modulating waveforms, identifying a second of the modulating waveforms that is instantaneously the minimum of the modulating waveforms, for a first phase associated with at least one of the first and second identified waveforms, substituting a first substitute waveform for the one of the first and second waveforms, for the first phase, modifying at least one of the first substituted waveform and duty cycle signals generated by comparing the first substituted waveform with the carrier signal as a function of a first rule set to substantially minimize the effects of turn on delays and for at least one of the second and third phases, modifying at least one of the associated modulating waveform and duty cycle signals generated by comparing the modulating

Abstract: Inverter-filter non-linearity blanking time and zero current clamping compensation is accomplished by comparing the average output current with the discontinuous current mode threshold values to determine when the average output current is entering a discontinuous current mode and introducing a compensation voltage to the inverter drive voltage in response to the average output current entering a discontinuous current mode to compensate for discontinuous current mode distortion of the inverter output voltage.

Abstract: An inverter apparatus can lengthen a lift span and improve efficiency. Instead of a conventional electrolytic capacitor, only a noise absorption film capacitor is provided in a DC intermediate circuit between rectifying and inverter circuits. In a voltage command generating unit, when a frequency set by a frequency setting unit is within a predetermined range including the frequency of an AC input power supply, PLL control is performed to make the frequency set by an output voltage command signal equal to the frequency of the AC input power supply voltage, and to substantially synchronize the peak value of an output voltage from the inverter circuit with the peak value of a voltage formed between both ends of the film capacitor. Accordingly, output voltage amplitude is generated when the frequency set by the output voltage command signal equals the frequency of the voltage of the AC input power supply.

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: The invention recognizes that filter size can be reduced substantially as power factor is permitted to deviate below unity in systematic ways. Preferred methods of the invention provide specific, computable waveforms that permit use of a minimum filter size given a desired target power factor.

Abstract: A power conversion apparatus for converting direct current from a power source to polyphase alternating current includes a plurality of carrier signal generators, a plurality of gate signal generators, and a plurality of legs. The carrier signal generators are configured and arranged to independently generate and transmit a plurality of carrier signals, respectively. The gate signal generators are operatively coupled to the carrier signal generators, respectively, to receive the carrier signals, each of the gate signal generators being configured and arranged to generate an on/off signal by comparing a command value of each phase of the polyphase alternating current and corresponding one of the carrier signals. The legs are connected to the gate signal generators. Each of the legs is operated based on the on/off signal transmitted from corresponding one of the gate signal generators to convert the direct current to each phase of the polyphase alternating current.

Abstract: A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.

Abstract: An inverter system comprises a PWM generator that generates a control signal that causes a switching device to output an output value, a carrier signal generator that outputs a carrier signal to the PWM generator, a carrier frequency changing unit that changes a frequency of the carrier signal, and a target frequency setting unit that sets a target frequency and calculates a specific frequency from the target frequency. The carrier frequency changing unit changes a carrier frequency so that the specific frequency matches with a harmonic component of each of values of the carrier frequency.

Abstract: This invention disclosed is a comprehensive power quality controller for substation in the electric power system and includes a Thyristor Controlled Reactor (TCR), pure tuned passive filter Zf, additional inductor L active power filter (APF), and a coupling transformer. The Thyristor Controlled Reactor (TCR) provides inductive reactive power and controls the active power filter (APF) as the current source, it is connected with the additional inductor La in parallel via the coupling transformer, then connected to the passive filter Zf in serial to consist a hybrid power filter system, which is connected to the power grid via the circuit breaker or thyristor. The comprehensive filter system provides required capacitive reactive power and filters the harmonic produced by the load and TCR system itself. Because the capacity of the active power filter (APF) is very small which is less than 1% of the harmonic source capacity, so it is a solution with low cost but simple and reliable control mode.

Abstract: An inverter unit includes a DC power source, an inverter circuit having two or more pairs of switching elements which are connected in parallel to the DC power source, so that a DC voltage of the DC power source is converted into a pulse train-like, pseudo-AC voltage output from the inverter circuit, and a PWM generator connected to the inverter circuit for adjusting the pseudo-AC voltage by pulse width modulation. Further, the inverter unit includes a voltmeter for detecting an actual, output voltage which is output from the inverter circuit, and a duty cycle controller for controlling an output duty cycle, so that the detected, actual, output voltage becomes a target output voltage. In this inverter unit, a desirable, output voltage may be obtained stably and accurately even if a voltage of a power source fluctuates.

Abstract: A power converting apparatus and method providing for the addition of a fourth power connection wire to the neutral point of the normal three phase load circuit. This allows delivery of combined current from the center of the DC link voltage to load. The added control enables a third harmonic injection to flow and allows for increased power rating per peak amp handled by the conversion system. Limiting of faults to the positive half versus the negative half of the DC system allows for more robust behavior when encountering these fault conditions.

Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.

Abstract: A method and system for reducing audible motor noise in a system for reconstructing motor phase current from a DC bus current comprising current pulses on a DC bus in a PWM inverter motor drive system having a PWM cycle, and for controlling the motor, which forms a command voltage vector according to a space vector modulation arrangement for controlling the motor; measures the DC bus current on the DC bus supplying power to the inverter to reconstruct said motor phase current; and determines when the command voltage vector results in an inverter switching state that prevents the measuring of the DC bus current from accurately indicating motor phase current.

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: In one embodiment, a PWM power supply controller asserts a PWM control signal synchronously to a clock signal of the PWM controller and also asserts the PWM control signal asynchronously to the clock signal.