Abstract: A method in connection with a frequency converter for correcting the power factor of the frequency converter, and a power factor correction unit. The method includes connecting the power factor correction unit between a rectifier bridge of the frequency converter and the supplying AC voltage network, generating with the power factor correction unit DC voltage from the AC voltage of the supply network and feeding the generated DC voltage to the frequency converter via the rectifier bridge of the frequency converter.

Abstract: A ripple reduction circuit for use in a current doubler rectifier has first and second inductors coupled via a first coupling coefficient. The first and second inductors generate a first and a second ripple current, respectively. A third inductor is coupled to the first and second inductors; and an impedance is connected in series with the third inductor, wherein the circuit generates a third ripple current opposing the combination of the first and second ripple currents generated by the first and second inductors.

Abstract: A device is disclosed for generating a stable high voltage, namely a high-voltage DC generator for a particle beam apparatus. A method is also disclosed for generating a stable high voltage for a particle beam apparatus. The high-voltage DC generator has a controllable voltage source, which is connected to an amplifier. The high-voltage DC generator ensures that fluctuations of the smoothed high voltage are detected by a capacitive divider and supplied to the amplifier. The amplifier controls the controllable voltage source in counterphase. The voltage of the controllable voltage source is superimposed on the smoothed high voltage. The sum of the voltage of the controllable voltage source and the smoothed high voltage forms the generated and stable high voltage, which is supplied to a particle beam apparatus.

Abstract: A driver circuit included in a power supply having a rectifier coupled to a single phase AC input voltage is disclosed. An example driver circuit includes a drive signal generator to generate a drive signal to be coupled to a variable impedance element. A voltage sensor is coupled to the drive signal generator and is to be coupled to sense a voltage across a high voltage capacitance. The driver circuit is to be coupled to control the variable impedance element in response to the voltage sensor. A low voltage capacitance is allowed to receive current from the input if the sensed voltage is less than a second threshold value. The low voltage capacitance is prevented from receiving current from the input if the sensed voltage is greater than a first threshold value.

Abstract: A method for selecting the optimum number of phases for a converter is provided, which selects a duty range using an input voltage and an output voltage, obtains ripple values for multiple phases in the duty range, and selects the optimum number of phases using the corresponding ripple values. The method for selecting the optimum number of phases for a converter includes a duty range selection step of selecting a duty range using an input voltage and an output voltage, a ripple value calculation step of obtaining ripple values for multiple phases within the selected duty range, a range ripple selection step of selecting one or more phases in the duty range, and a rated ripple selection step of selecting the phases having the minimum ripple value in a rated duty among the phases selected in the range ripple selection step.

Abstract: An inverter apparatus that can lengthen a lift span provides only a noise absorption film capacitor in a DC intermediate circuit between rectifying and inverter circuits, instead of a conventional electrolytic capacitor. 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 the inverter circuit output voltage 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 converter circuit for converting an output voltage from an AC power supply includes a rectifier circuit for rectifying the output voltage of the AC power supply; first and second capacitors connected in series, for smoothing the output of the rectifier circuit; and a switch circuit for switching the connections between the respective capacitors and the AC power supply so that the output voltage of the AC power supply is applied to each of the respective capacitors at a cycle that is shorter than the cycle of the AC power supply.

Abstract: In one aspect, in general, the invention features a control system configured for use with a three-phase PWM converter. The control system receives an input signal from a three-phase power supply and provides an output signal at a DC link. A voltage-separating module generates on the basis of the input signal a positive sequence voltage component and a negative sequence voltage component in a rotating reference frame. A reference current computation module uses at least the positive sequence voltage component and the negative sequence voltage component to compute a first reference current and a second reference current. A current regulating module uses at least the first reference current and the second reference current to generate a command signal. The command signal is provided to a driving circuit of the three-phase PWM converter for generating a regulated DC bus voltage at the DC link.

Abstract: Methods and systems are disclosed for reducing alternating current ripples in direct current electrical power generation systems with one or more regulated permanent magnet machines. Ripple suppression is achieved, in one aspect, by modulating the control current of a regulated permanent magnet machine.

Abstract: A voltage monitoring device 30 includes an AC input portion 31, a rectifier circuit 32, and a detection circuit 33. The AC input portion 31 receives alternating current output from a DC-AC inverter unit 13. The rectifier circuit 32 rectifies the alternating current received at the AC input portion 31. The rectifier circuit 32 is formed by a full-wave rectifier circuit. The detection circuit 33 detects the output voltage of the rectifier circuit 32. The detection circuit 33 includes a differential amplifier circuit 34. First and second capacitors C1 and C2 are respectively connected to two wires 36a and 36b, which connect the AC input portion 31 and the rectifier circuit 32. The capacitors C1 and C2 are set to have the same capacitance.

Abstract: A modification of a control loop of a primary side sensing power control system that uses a different and unique relationship to accomplish the constant current control while attenuating the affects of a ripple voltage.

Abstract: A ripple filter circuit for ensuring the driving of a driving subject while efficiently eliminating ripple even when the operational voltage margin is small. A first transistor, which is connected to a power supply voltage line, is connected to a ground line via a load of the driving subject. A second transistor, which has substantially the same characteristics as the first transistor, and a dummy load are arranged between the power supply voltage line and the ground line. An operational amplifier includes an inverting input terminal, connected between the second transistor and the dummy load, and a non-inverting terminal at which the voltage is decreased by a predetermined voltage from the power supply voltage. The operational amplifier also includes an output connected to the gate terminal of the second transistor and to the gate terminal of the first transistor via a lowpass filter.

Abstract: A capacitive power supply circuit, comprising a power storage element between two output terminals for providing a rectified output voltage; in series between a first input terminal for applying an A.C. voltage and a first of the output terminals, at least one capacitor and a first diode; a switch controllable by application of a signal on a triggering terminal; and means for controlling said switch to the on state when the output voltage is in a predetermined range of values.

Abstract: Certain exemplary embodiments comprise a system comprising a plurality of Active Front End units adapted to be electrically coupled to a direct current (DC) bus. Each of the plurality of Active Front End units can be adapted to be electrically coupled to a separate winding of a transformer of a plurality of transformers. Each of the plurality of Active Front End units can be adapted to convert alternating current (AC) voltage to a DC voltage. Each of the plurality of Active Front End units can be adapted to supply the DC voltage to the DC bus. The DC bus can be adapted to be electrically coupled to a plurality of inverters.

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: 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: An unregulated isolated DC/DC converter is configured to receive an input signal and to provide an output signal. A ripple control circuit is coupled to the unregulated isolated DC/DC converter, wherein the ripple control circuit is configured to reduce an amount of low frequency ripple transferred to the output signal from the input signal.

Abstract: A method and apparatus for altering converter control as a function of the degree of unbalance in supply line voltages to substantially eliminate second harmonics on the supply lines caused by active control of the converter including identifying supply line peak amplitude values and using the peak values to identify potential second harmonics and then altering command values as a function of the potential second harmonic components.

Abstract: A power supply system is disclosed. In one embodiment the power supply system includes a source of DC power that provides a DC bus voltage between a pair of DC bus terminals, and a power supply that receives power from the DC bus terminals and delivers power to a load. An output measurement circuit measures output parameters delivered by the power supply and provides a corresponding set of feedback signals. A feedback regulator connected receives the feedback signals and provides a feedback output signal operative to regulate the output of the power supply to achieve a desired voltage, current, or power level specified by a setpoint signal. An adaptive feedforward circuit connected to the feedback regulator and to the DC bus terminals provides a combined regulation signal to the power supply that minimizes perturbations in the output of the power supply due to DC bus ripple voltage.

Abstract: A voltage converter includes a transformer circuit, a filter, and a controller. The transformer circuit is coupled to the filter, and the controller is coupled to the transformer circuit and the filter. The transformer circuit includes an input port and an autotransformer coupled to the input port. The voltage converter receives an input signal at the input port and generates a transformer output signal from a transformer output port. The filter receives the transformer output signal on a filter input port and the filter generates an output signal at an output port. The controller receives the output signal from the filter and provides one or more control signals to the transformer circuit to control the output signal.

Abstract: A ripple current reduction circuit is provided that reduces the ripple current of a transformer by providing a substantially opposite or inverse ripple of an auxiliary current that can be combined with the ripple current of the transformer for cancellation or reduction of the ripple current.

Abstract: An AC adaptor has a switching regulator for converting alternate current to direct current. Filters are provided to filter conducted noise, and a filter switcher switches to the filter to be used in the AC adaptor. A detector detects power consumption state of an electrical apparatus. A state-filter relations storage stores correlations between the power consumption states of the apparatus and the filters to determine the filter that meets requirements so that the conducted noise to be filtered in the AC adaptor is suppressed to a standard limit value or less and so that power consumption is made lowest among the filters. A filter switching controller controls the filter switcher to switch to the filter to be used in the AC adaptor in correlation to the detected power consumption state of the electrical apparatus.

Abstract: A reactive power compensator continues operation even when a higher harmonic wave component of an alternating-current power system increases. For an alternating current electric amount indicating one of an alternating voltage and an alternating electric current in an alternating-current power system, the reactive power compensator outputs a changing amount showing a change of the alternating current electric amount. An electric current command limits an electric current command signal based on the changing amount. For example, the changing amount is changed in accordance with the higher harmonic wave component included in the alternating current electric amount.

Abstract: A controller for, related method of controlling a switch of, a power converter and a power converter employing the same. The controller is employable with a power converter including a switch of a power train configured to conduct for a duty cycle and provide a regulated output characteristic at an output thereof. In one embodiment, the controller includes a sparse analog-to-digital converter configured to determine a difference between the output characteristic and a desired characteristic and provide an error signal representing the difference in discrete steps. A magnitude of the discrete steps is small when the difference is small and the magnitude of the discrete steps is larger when the difference is larger. The controller also includes a duty cycle processor configured to provide a digital duty cycle signal to control the duty cycle of the switch as a function of the error signal.

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 low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.

Abstract: Power supply apparatus includes a power factor corrector (PFC) unit, which is adapted to receive an AC voltage from an AC source, and to smooth the AC voltage while adjusting a waveform of an AC input current from the AC source relative to the AC voltage so as to generate a PFC output voltage made up of a DC component with a residual AC ripple. A regulator is coupled to receive an indication of a ripple amplitude and a ripple phase of the residual AC ripple and to generate, responsive thereto, a correction voltage which is combined with the PFC voltage to generate a DC output voltage in which the AC ripple is substantially reduced relative to the PFC voltage.

Abstract: A device for inhibiting power supply voltage fluctuation that is caused by fluctuation of a load current generated by a load circuit. The device includes a current consumption circuit, a data generation circuit, and a D/A converter. The current consumption circuit is connected to a power supply and the load circuit to generate a consumption current that flows parallel to the load current of the load circuit. The data generation circuit controls the consumption current of the current consumption circuit in order to inhibit fluctuation of an output current of the power supply, which is the sum of the load current and the consumption current, when the load current rises and when the consumption current falls. The D/A converter converts the digital signal to an analog signal and provides the analog signal to the current consumption circuit.

Abstract: The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

Abstract: An active tracking filter reduces low frequency noise (such as a 20 Hz ringing signal) riding on a DC voltage (e.g., on the order of (−40 VDC) applied to a load such as a subscriber line interface circuit (SLIC). A controllable impedance device, such as a FET operating in its linear range, is coupled in circuit between a source of the DC voltage and the load. A low frequency voltage average detector circuit senses the average low frequency variation of the DC voltage. An output voltage sensor senses a DC output voltage at the output of the controllable impedance. A differential error amplifier circuit has a first input coupled to the low frequency voltage average detector circuit, a second input coupled to the output voltage sensor, and an output coupled to a control terminal of the controlled impedance device.

Abstract: A preconditioner comprises a rectifier, a switch mode power supply, and a feedback path for feedback of a preconditioner output voltage to a control block. The rectifier is arranged to receive an AC voltage from a voltage supply and to rectify the AC voltage. The switch mode power supply is arranged to control the current in the rectifier. The control block has a bandwidth equal to or greater than the voltage supply frequency. The feedback path has a bandpass filter connected to the output voltage and generates a feedback signal based on the output voltage and an output signal from the bandpass filter. The feedback signal has reduced ripple around the passband of the filter.

Abstract: An electric power translating device employs a converter for converting an AC source voltage into a DC voltage, a smoothing capacitor connected at the DC side of the converter, an inverter for inverting the DC from the smoothing capacitor into an AC and for supplying the AC to an AC motor and means for controlling the voltage, frequency or phase in the AC output from the inverter. The device further includes means for regulating at least one of voltage, frequency and phase in the AC output of the inverter based on a ripple frequency component contained in the AC output of the inverter and associated with the rectification by the converter. Whereby, beat phenomenon caused by rectification ripple is suppressed.

Abstract: An electric power translating device employs a converter for converting an AC source voltage into a DC voltage, a smoothing capacitor connected at the DC side of the converter, an inverter for inverting the DC from the smoothing capacitor into an AC and for supplying the AC to an AC motor and means for controlling the voltage, frequency or phase in the AC output from the inverter. The device further includes means for regulating at least one of voltage, frequency and phase in the AC output of the inverter based on a ripple frequency component contained in the AC output of the inverter and associated with the rectification by the converter. Whereby, beat phenomenon caused by rectification ripple is suppressed.

Abstract: A circuit comprises at least one electronic switch which is operatively connected to an inductive load, is intended to be driven by means of an on-off signal and, in an enabled condition, can connect the load to a direct-current voltage supply, at least one freewheeling circuit branch which comprises a diode and can recirculate the transient current which flows through the load each time the switch is disabled, and a filtering circuit connected between the diode and the voltage supply and comprising a parallel capacitor connected to the diode and a series inductor connected between the diode and the voltage supply. The freewheeling circuit branch and the filtering circuit are connected substantially in series with one another in a circuit branch which is operatively connected in parallel with the load.

Abstract: A method and system for compensating for voltage notches in phase locked loop (PLL) control devices. A bridge firing controller receives signals representative of two of the line to line voltages received by the bridge. The controller includes a PLL synchronizing tool which receives the line to line voltage signals and generates a synchronizing phase error signal for aligning the phases of the two input signals. The controller, for a predetermined period following bridge firing, determines whether a voltage notch has occurred. If so, the controller substitutes model control signals for actual control signals so as to reduce the effect of the notch on the generated phase error signal used for synchronization. If not, the controller continues to use the actual control signals to generate the phase error signal. Once the predetermined period has expired, the controller utilizes the actual control signals to generate the phase error signal.

Abstract: The present invention relates to an electric power unit with a condenser input type rectification circuit which converts an alternating current power source to a direct current voltage, and more particularly, to an electric power unit for inverter-controlled refrigerators. An electric power unit according to the present invention feeds electric power to a load (7), which comprises an alternating current power source (1), a bridge-type rectification circuit (2) having an input from the alternating current power source (1) and consisting of bridge-connected diodes (D1, D2, D3, D4), an auxiliary capacitor (3) connected in parallel to an output of the bridge-type rectification circuit (2), a series circuit of a reactor (4) and a diode (5) connected between one output of the bridge-type rectification circuit (2) and the load (7) so as to flow a load current in a forward direction, and a smoothing capacitor (6) connected in parallel to the load (7).

Abstract: A filter for a direct current voltage converter includes chokes L1, L2 and capacitors C1, C21. The filter is connected between the feeding source and the direct voltage converter, and an auxiliary alternating voltage source U.sub.H connected in series with the capacitor C1 has the same alternating voltage amplitude as the interference voltage U.sub.C1 at 180.degree. phase angle rotation.

Abstract: The present invention relates to an electric power unit with a condenser input type rectification circuit which converts an alternating current power source to a direct current voltage, and more particularly, to an electric power unit for inverter-controlled refrigerators.An electric power unit according to the present invention feeds electric power to a load (7), which comprises an alternating current power source (1), a bridge-type rectification circuit (2) having an input from the alternating current power source (1) and consisting of bridge-connected diodes (D1, D2, D3, D4), an auxiliary capacitor (3) connected in parallel to an output of the bridge-type rectification circuit (2), a series circuit of a reactor (4) and a diode (5) connected between one output of the bridge-type rectification circuit (2) and the load (7) so as to flow a load current in a forward direction, and a smoothing capacitor (6) connected in parallel to the load (7).

Abstract: A method of reducing feedback action on a timely flow of current, which is drawn by a load from a network via rectifier, by active filtering of upper harmonics, which are superimposed on a network first harmonic, with a power factor corrector circuit with a pulse-width modulation of a switch signal which influences the current drawn from the network and flowing through a boost-converter, with the method including dividing a current path between the rectifier (2) and the load (10) in a plurality of parallel channels (It, Jt), and providing in each channel (It, Jt) a similarly active filter, with switch signals of both active filters having a substantially same pulse-width modulation and being phase-sifted relative to each other so that a reduced ripple of the total current, which results form cumulative superimposition of currents in separate channels, is produced at a network input (9); and an active filter for effecting the method.

Abstract: A method and apparatus reduces an output ripple signal of a power supply (200) for supplying a DC voltage and current to a load. One of the output ripple signal and an intermediate ripple signal is sensed to produce a control signal at a ripple sensing element (206), and a rectangular pulse carrier signal is generated by a pulse width modulator (302), the signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy. The rectangular pulse carrier signal operates at a frequency substantially higher than the control signal. The PWM signal is coupled into a portion of the power supply through a transformer (202). The transformer is arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal.

Abstract: An integrated three-phase power converter and method of operation thereof is provided. The integrated three-phase power converter includes: (1) first and second power switches coupled between corresponding rails of said power converter, (2) an input stage, including first, second and third L-C branches coupled between said first, second and third phase inputs and a node between said first and second power switches, adapted to receive phase voltages from a source of electrical power, and (3) an output stage, coupled to said first and second power switches, that provides a DC output voltage at said output, said first and second power switches cooperating to employ said input stage to reduce input current total harmonic distortion (THD) on all three of said phase inputs and said output stage to convert said phase voltages to said DC output voltage.

Abstract: The present invention relates to a device for limiting transient variations of a voltage for supplying a load from a dc/dc converter, including an input terminal, that receives the voltage provided by the converter, and connected to an output terminal of the device connected to the load; a first power transistor connected between a supply voltage of the converter and the output terminal; a second power transistor connected between the output terminal and the ground; and means for linearly and individually controlling each power transistor in case of an abrupt variation of the load.

Abstract: For use with a boost converter having first, second and third input inductors, a switching network, method of reducing input current total harmonic distortion (THD) associated with the boost converter, and boost converter employing the switching network and method. In one embodiment, the switching network includes a first switch coupled between corresponding rails of the boost converter. The switching network also includes first, second and third L-C resonant networks wye-coupled to a common node and coupled to the first, second and third input inductors, respectively. The first switch and the first, second and third L-C resonant networks cooperate to create resonant voltages across, and induce phase currents through, the first, second and third input inductors to reduce input current THD associated with the boost converter.

Abstract: An AC-DC converter for connecting an AC supply and a DC has a rectifier, and a harmonic correction circuit formed of (a) thyristor inverter legs connected at a common output point to form a Y switch, or separately at positive and negative terminals and (b) a voltage selection circuit for selecting a voltage derived from one of the positive and negative DC rails, or the AC lines, to control current shape and turn-off the thyristors. The thyristors are turned on by, and may also be turned off by, a controller. The voltage selection network may be a resonant circuit that uses ramping of the voltage at the outputs from the thyristors to turn the thyristors off or switches controlled by the controller.

Abstract: Two parallel regulator stages, each comprising a transistor (T1, T2, respectively), are provided. The transistor (T2) forms part of the indirect parallel regulator stage and acts directly on the rectifier. It is capable of taking up comparatively large currents and hence is comparatively slow. The transistor (T1) forms part of the direct regulator stage and operates in parallel with the sustaining capacitor. Because of the coarse control provided by the transistor (T2), it need take up small currents only and can hence have a very fast control behavior. Because of the coarse control by the transistor (T2), the alternating voltage on the antenna terminals (LA and LB) quickly breaks down when the RF signal is interrupted; consequently, the transmission rate can be increased in the case of pause interval modulation. Static discharges are also dissipated by the transistor (T2), so that no additional protective circuitry is required for this purpose.

Abstract: A three-phase bridge rectifier includes three bidirectional switching circuits each including a single-phase rectifier circuit having four single-phase bridge-connected diodes and a semiconductor switching element connected between DC output terminals of the single-phase rectifier circuit, three AC side reactors each connected between one of two AC input terminals of each bidirectional switching circuit and each one of output terminals of a three-phase AC power supply, three positive side diodes each having an anode connected to a positive side DC output terminal of each one of the bidirectional switching circuits and a cathode connected to a positive side DC bus, three negative side diodes each having a cathode connected to a negative side DC output terminal of each one of the bidirectional switching circuits and an anode connected to a negative side DC bus, a smoothing capacitor including two capacitors series connected between the positive and negative side DC buses and a neutral terminal connected to the

Abstract: A method for controlling the speed of a motor driven by an unregulated voltage supply is disclosed. The disclosed method comprises obtaining a ripple signal (V.sub.R) representative of the ripple component of the supply voltage, and modulating the motor current (I.sub.M) in response to at least the ripple signal to maintain the speed of the motor at a prescribed target speed.

Abstract: A device for suppressing higher harmonic current of a power source and applicable to a switching power source, air conditioner with an inverter, lamp regulator or the like. The device suppresses higher harmonic current by increasing the conduction angle of input current.

Abstract: A switching power supply for providing a dc voltage with substantially no ripple includes a rectifier for rectifying an ac supply, a filter for filtering the rectifier output and an inductor for current limiting. The filtered output includes a ripple generated by the equivalent series resistance of the filter. This ripple is sensed and used to generate a correcting signal. The correcting signal is arranged and sized so that when it is superimposed on the filtered output, the ripple is substantially eliminated. Preferably the correcting signal is coupled to the inductor.

Abstract: A low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.