57 results about "Current shaping" patented technology

A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes corresponding to different levels of input voltage or output current. The power converter comprises a power stage for delivering the electrical power from the power source to the load, a switch in the power stage that electrically couples or decouples the load to the power source, and a switch controller coupled to the switch for controlling the on-times and off-times of the switch according to the plurality of operation modes. Each of the operation modes correspond to associated ranges of at least one of an input voltage to the power converter and an output current from the power converter, where the associated ranges are different for each of the operation modes.

A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes corresponding to different levels of input voltage or output current. The power converter comprises a power stage for delivering the electrical power from the power source to the load, a switch in the power stage that electrically couples or decouples the load to the power source, and a switch controller coupled to the switch for controlling the on-times and off-times of the switch according to the plurality of operation modes. Each of the operation modes correspond to associated ranges of at least one of an input voltage to the power converter and an output current from the power converter, where the associated ranges are different for each of the operation modes.

A single-stage input-current-shaping (S<2>ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S<2>ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S<2>ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S<2>ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.

Methods and apparatus for reducing overall seeking acoustics in a head-disk apparatus are disclosed. In accordance with one aspect of the present invention, a method for reducing overall seeking acoustics in a disk drive apparatus, which includes an actuator, involves calculating an error that is a measure of a difference between a desired trajectory for the actuator and an actual trajectory for the actuator, and calculating a preliminary gain. The method also includes determining when the preliminary gain exceeds a minimum acceptable gain limit, and updating a current command using the preliminary gain and the velocity error when the preliminary gain exceeds the minimum acceptable gain limit. The preliminary gain is generally arranged to enable the updated current command to reduce the overall seeking acoustics. The updated current command is sent to a power amplifier which then generates a seek current signal using the power amplifier and the updated current command. The updated current command allows the actual trajectory to substantially follow the desired trajectory.

A multi-mode control scheme for an LED lamp system uses the detected firing angle of an AC input voltage waveform to select from multiple regulation modes. In operation, a current controller compares the detected firing angle to one or more specified thresholds and selects the appropriate regulation scheme based on the comparison result. When the detected firing angle is less than a first firing angle threshold, the controller employs a current shaping regulation mode. When the detected firing angle is greater than a second firing angle threshold, the controller employs a switching cycle-I_Peak modulation regulation mode. And when the detected firing angle is greater than the first firing angle threshold and less than the second firing angle threshold, the controller employs a hybrid regulation mode.

An AC / DC power converter has an AC input and a DC output, with an input rectifier circuit coupled to the AC input. The input rectifier circuit includes a passive half-bridge rectifier circuit functional to provide passive rectification of an AC input power sign and at least one current shaper circuit. The current shaper circuit includes an input inductor coupled between the AC input and a switch node in the input active rectifier circuit. The input current shaper circuit is functional to shape an AC input current signal associated with an AC input power signal to a substantially sinusoidal current signal. A bulk capacitor circuit is coupled to the input active rectifier circuit. A DC / AC converter circuit is coupled to the bulk capacitor circuit. A resonant circuit is coupled to the DC / AC converter circuit and an output rectifier circuit may be coupled between the resonant circuit and the DC output.

A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes, where at least one of the operation modes is a peak current switching mode. Under the peak current switching mode, a switch controller controls the switch in the power converter to be kept on until the current through the switch reaches a peak current value corresponding to a given phase of the input voltage signal to the power converter. The peak current values have a reference shape, which may be a trapezoidal. The power converter may have any topology, such as a flyback-type power converter or a boost-type power converter.

Disclosed is a PFC (power factor correction) device for shaping an input current of a power converter. The device includes means for receiving a rectified input voltage derived from an AC input voltage; load determining means for determining a load value L which represents the power drawn by a load supplied by the power converter; current shaping means for shaping the input current of the power converter to follow a reference waveform; and control means for controlling the current shaping means to operate over a conduction interval α during each positive and negative half cycle of the AC input voltage. The duration of the conduction interval is controlled in accordance with the load value L. The current shaping means may shape the input current to follow the reference waveform which crosses zero at phase angles which substantially correspond to the start and end of the conduction interval.

A method is shown to create soft transition in selected topologies by controlling and designing a current pulse injection in front of the output choke to overwhelm the output current at a certain point in the switching cycle.

The invention discloses an LLC primary side constant current control device and a compensation current signal extraction method. The control device receives voltage signals at two ends of a transformer winding of a converter and sampled primary side resonance current signals, extracts first resonance interval current signals from the primary side current shaping signals according to a time interval, shapes the first resonance interval current signals according to the voltage polarity of the transformer winding, adds bias voltage and obtains first resonance interval average current signals after average processing. The method includes the steps of taking the initial and end current values of the shaped and biased primary side current shaping signal in the first resonance interval, summing the initial and end current values to solve the mid-value and obtain a compensation current signal, and subtracting the compensation current signal from the average current signal in the first resonance interval to obtain a signal reflecting the average value of the output current. The invention can omit an optical coupler and a secondary side feedback circuit, and effectively improves the stability of the circuit. In addition, the primary side constant current control device can be further integrated into a single chip, and the circuit cost is further reduced.

A converter topology that eliminates reverse recovery losses in its output rectifying semiconductor devices employs an AC injection voltage source in series with a power transformer primary winding. Input semiconductor switches in the converter's primary circuit are controlled to provide in the power transformer secondary a voltage across the winding or windings in a first direction forward biasing one of the output rectifying devices followed by a lower level reverse biasing voltage produced by the injection voltage. This lower level voltage across the secondary turns off the previously conducting rectifier device and drives carriers out of its semiconductor junction or junctions to eliminate reverse recovery losses occurring when the secondary applies a higher level reverse bias across the non-conducting rectifier device. The injection voltage source can be a transformer in addition to the power transformer having a primary winding in series with the primary winding of the power transformer and a secondary winding connected to ground through a capacitor. In addition to preventing reverse recovery losses in the rectifying devices in the secondary, the injection voltage transformer also injects an AC triangular waveform current into the current in the converter primary input circuit to the junction of the semiconductor switches where they are connected in a bridge circuit supplying the power transformer primary. By this, the injection voltage source assures zero voltage switching of the semiconductor switches even at light loads.

A converter topology that eliminates reverse recovery losses in its output rectifying semiconductor devices employs an AC injection voltage source in series with a power transformer primary winding. Input semiconductor switches in the converter's primary circuit are controlled to provide in the power transformer secondary a voltage across the winding or windings in a first direction forward biasing one of the output rectifying devices followed by a lower level reverse biasing voltage produced by the injection voltage. This lower level voltage across the secondary turns off the previously conducting rectifier device and drives carriers out of its semiconductor junction or junctions to eliminate reverse recovery losses occurring when the secondary applies a higher level reverse bias across the non-conducting rectifier device. The injection voltage source can be a transformer in addition to the power transformer having a primary winding in series with the primary winding of the power transformer and a secondary winding connected to ground through a capacitor. In addition to preventing reverse recovery losses in the rectifying devices in the secondary, the injection voltage transformer also injects an AC triangular waveform current into the current in the converter primary input circuit to the junction of the semiconductor switches where they are connected in a bridge circuit supplying the power transformer primary. By this, the injection voltage source assures zero voltage switching of the semiconductor switches even at light loads.

An input current shaping AC to DC converter with PFC front end that reduces input current harmonics is provided. In one embodiment, an AC to DC converter connectable with an alternating current source and operable to output a direct current has a PFC front end followed by a DC / DC converter. The PFC front end reduces harmonic components present in an input current waveform received by the PFC front end from the alternating current source and includes current steering circuitry and, optionally, valley filling circuitry. The DC / DC converter is one that presents pure resistive input impedance to the PFC front end. The DC / DC converter outputs the direct current to a load connected thereto.

Provided herein is are unified control methods and implementations for controlling single and three-phase power converters. In an exemplary embodiment, a unified controller is provided that can be used to control a three-phase three-wire Voltage Source Inverter (VSI), a three-phase four-wire VSI, a three-phase grid-connected power converter for current shaping, and a single-phase full bridge VSI.

Disclosed is a PFC (power factor correction) device for shaping an input current of a power converter. The device includes means for receiving a rectified input voltage derived from an AC input voltage; load determining means for determining a load value L which represents the power drawn by a load supplied by the power converter; current shaping means for shaping the input current of the power converter to follow a reference waveform; and control means for controlling the current shaping means to operate over a conduction interval α during each positive and negative half cycle of the AC input voltage. The duration of the conduction interval is controlled in accordance with the load value L. The current shaping means may shape the input current to follow the reference waveform which crosses zero at phase angles which substantially correspond to the start and end of the conduction interval.

A power converter operable to draw an input current that is in phase with an input voltage of the power converter and proportional to a voltage of the input voltage of the power converter includes a drive switch, a waveform generator, and a current shaping circuit. The drive switch is connected between an input inductor and ground and draws current through the input inductor when turned on. The current shaping circuit provides an on-time of the drive switch for a next cycle of the drive switch as a function of an input current decay time, a switching period of the waveform generator, and an output voltage of the power converter. The waveform generator is responsive to the on-time provided by the current shaping circuit for selectively turning the drive switch on and off to cycle the drive switch as a function of the received on-time.

Techniques and structures for achieving a more uniform current density in solder ball contact areas for a ball-grid-array semiconductor package are presented. Current density may be made more uniform by introducing electrically non-conductive regions into one or more areas that form a dedicated power rail within a package substrate that is configured to be connected with a die. Additionally or alternatively, the number of μvias that connect each solder ball contact area with conductive areas within the package substrate may be individually tailored based on the desired current density at each solder ball contact area.

The invention relates to an antenna tuner impedance detection method based on phase detection. The method includes the following steps that firstly, the inductance coil coupling mode is adopted in a current sampling circuit, and a voltage sampling signal is acquired from a radio frequency link in a resistance voltage dividing mode; secondly, a circuit sampling signal and the voltage sampling signal are subjected to detection, amplifying and A / D sampling to acquire a current amplitude value and a voltage amplitude value; thirdly, shunt signals of the current sampling signal and voltage sampling signal are subjected to wave shaping through a comparator, a sine wave becomes a square wave, then the square wave is amplified, and a standard square-wave signal is acquired; fourthly, the phase of an impedor and the relation between the capacitive reactance and the inductive reactance of the impedor are judged through the voltage and current shaping square wave signals and a voltage and current square wave xor output signal. The method has the advantages that the input impedance of an antenna can be precisely measured, resource consumption is small, circuits are simple, the measurement speed is high and the tuning speed of an antenna tuner can be guaranteed.

We describe an inductive device for use in current shaping applications. The inductive device includes a core body comprising a first gap and a second gap, and at least one transition region between the first and second gaps. The shape of each gap in the inductive device can control a slope between two inductance values as a function of load current. The inductive device is capable of providing low total harmonic distortion (THD) AC output waveforms to achieve high efficiency.

A power converter (920) operable to draw an input current that is in phase with an input voltage (140) of the power converter and proportional to a voltage of the input voltage of the power converter includes a drive switch (44), a waveform generator (126) and a current shaping circuit (120). The drive switch is connected between an input inductor and ground and draws current through the input inductor when turned on. The current shaping circuit provides an on-time of the drive switch for a next cycle of the drive switch as a function of an input current decay time, a switching period of the waveform generator, and an output voltage of the power converter.

A current shaping phase leg bus bar for power electronics systems includes a first terminal connector, a second terminal connector, insulated from the first terminal connector, and a third terminal connector, insulated from the first and second terminal connectors. At least one of the terminal connectors is a current shaping terminal connector that includes one or more layers having a plurality of pre-defined locations for electrical connections, said plurality of pre-defined locations including one or more first locations and a plurality of second locations, and includes one or more gaps within or among its one or more layers, to provide substantially balanced conductive pathways among its one or more first locations and its plurality of second locations.

A PFC circuit according to the invention is connected to a grid, includes an input filter and a rectifier connected to a converter. A control circuit generates the reference current for the current regulator of the converter that controls its input current. Thereby, the reference current is generated by adding an offset current (I0) to a standard reference current and adapting the magnitude of the standard reference current to compensate for a change of the input power resulting from the addition of the offset current (I0). However, due to the addition of the offset current (I0) the magnitudes of some lower harmonic components of the input current of the power supply unit are increased and the magnitudes of some higher harmonic components of the input current are decreased such that the power supply may draw more current from the grid.

A hybrid diode-less power converter topology of the present invention converts power from an AC power source to a variable load with high efficiency. The power converter includes a non-symmetrical arrangement of rectifying switches for rectifying an input AC voltage and shaping switches for shaping an input AC current. The shaping switches are operated in Continuous Conduction Mode (CCM) based on an input AC current. Operation of each of the rectifying switches and shaping switches are further controlled wherein a commutation time for the shaping switches is associated with a first voltage rise and fall time (e.g., less than 10 ns), and a commutation time for the rectifying switches is associated with a second voltage rise and fall time (e.g., at least 100 ns), wherein the first voltage rise and fall time is less than the second voltage rise and fall time by a factor of nine or more.

A bus bar includes a load terminal connector comprising a conductive plate that extends from a first edge to an opposite second edge and extends from a third edge to an opposite fourth edge. The third and fourth edges extend from the first edge to the second edge. The plate includes a window opening located between the first and second edges and between the third and fourth edges. The plate also includes a slot extending into the plate from the first edge to the window opening. The plate includes first and second sets of openings configured to receive connections with first and second power terminals of switch packages. The first set of openings and the second set of openings are located on opposite sides of the slot.

The invention discloses a non-contact type three-phase current detection system. The system comprises an induced loop current sampling unit, a magnetic induction sampling unit, a current shaping unit,a signal processing unit and a current monitoring unit; the magnetic induction sampling unit is a magnetic induction chip and is matched with the current sampling unit, and the magnetic induction sampling unit is used for inducing the three-phase current acquired by the induced loop current sampling unit; the current shaping unit is used for shaping the three-phase current sensed by the magneticinduction sampling unit; the signal processing unit is used for performing analog-to-digital conversion and filtering processing on the shaped three-phase current; and the current monitoring unit is used for verifying the three-phase current processed by the signal processing unit according to a preset current error. The non-contact three-phase current detection system provided by the invention not only is simpler in structure, but also can realize accurate and stable sampling and verification diagnosis of the three-phase current, and is better in performance.