Abstract: A system, method and apparatus for contact-less charging of battery operated devices, including a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC, wherein the method obviates the need for a voltage controller in each of both the host and the portable stages. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. In one embodiment, component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment, charging efficiency is maximized regardless of the output voltage of the battery.

Abstract: This paper studies the recovery of the voltage after a voltage dip due to a fault in a three-phase system. The instant of voltage recovery corresponds to the instant of fault clearing. For single-phase and phase-to-phase faults, a single point-on-wave of voltage recovery can be defined. For two-phase-to-ground and three-phase faults, the recovery takes place in two or three steps. The voltage recovery is described in a systematic way by using a classification of three-phase unbalanced voltage dips. The voltage recovery needs to be modeled correctly for studies of equipment immunity against voltage dips.

Abstract: A switched mode power supply having a regulated reflected voltage. In one embodiment, a switched mode power supply includes a power supply regulator coupled between a positive input supply rail of the power supply and a primary winding of an energy transfer element. The reflected voltage across the primary winding of the transfer element is related to the output voltage across a secondary winding of the energy transfer element according to the turns ratio of the energy transfer element. The power supply regulator is coupled to regulate the reflected voltage across the primary winding, thereby regulating the output voltage across secondary winding. In one embodiment, the reflected voltage across the primary winding is sensed through a current representative of the reflected voltage received by the power supply regulator.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply. According to one embodiment, the RF power supply includes a direct current (DC) voltage source that provides a DC voltage within a predetermined voltage range; an amplifier, coupled to the DC voltage source, that provides an alternating voltage to a tank circuit connected to an output of the RF power supply; a frequency controller, coupled to the amplifier, to set the frequency of the alternating voltage produced by the amplifier; and a sensor, coupled to the load, to provide a signal to the frequency controller, where the frequency controller sets the frequency of the alternating voltage based on the signal received from the sensor.

Abstract: A memory system including an array of memory cells, a programming voltage node for receiving a first programming voltage, a memory controller which controls memory programming operations on the array of memory cells, and voltage detection circuitry, operably coupled to the memory controller and the programming voltage node, with the voltage detection circuitry being configured to enable the memory controller to initiate one of the programming operations if the first programming voltage exceeds a first voltage level and to continue the programming operation once the programming operation has been initiated if the first programming voltage drops to a second voltage level and to terminate the programming operation once the programming operation has been initiated if the first programming voltage drops below the second voltage level, with the first voltage level being greater than the second voltage level. And a method of controlling the operation of a memory system which comprises an array of memory cells, the method comprising the steps of providing a first programming voltage, initiating a memory programming operation if the first programming voltage magnitude exceeds a first voltage level, continuing the initiated programming operation if the first programming voltage remains greater in magnitude than a second voltage level, with the first voltage level magnitude being greater in magnitude than the second voltage level, and terminating the initiated programming operation if the first programming voltage magnitude drops below the second voltage level.

Abstract: When paralleled to the utility bus, synchronous generators can be controlled using either terminal voltage or VAr/power factor control. Selection is dependent upon the size of the generator and the stiffness of the connecting utility bus. For large generators where the kVA is significant, these machines are usually terminal voltage regulated and dictate the system's bus voltage. When smaller terminal voltage regulated generators are synchronized to a stiff utility bus, the system voltage will not change as the smaller generator shares reactive loading. However, if the system voltage changes significantly, the smaller generator, with its continuous acting terminal voltage regulator, will attempt to maintain the voltage set point. As the voltage regulator follows its characteristic curve, it may cause either over or under excitation of the smaller generator. Excessive system voltage may cause a small generator to lose synchronizing torque, while low system voltage may cause excessive heating on the generator or excessive overcurrent operation of the excitation system. Maintaining a constant reactive load on the smaller generating unit can reduce the generator field current variations and, thus, reduce the maintenance of the collector rings and brushes. This paper illustrates the effect of changing system bus voltage on small generators utilizing voltage versus VAr/power factor regulation.

Abstract: An adaptive off-time modulator of a PWM controller is provided for power saving in the light-load and no-load conditions. The maximum on-time is kept as a constant and a bias current of the oscillator in the PWM controller is moderated to achieve the off-time modulation. Reduction of the bias current increases the off-time of the switching period. The bias current is a function of the supply voltage and the feedback voltage, which is derived from a voltage feedback loop. A threshold voltage defines the level of the light load. A limit voltage defines the low level of the supply voltage. A bias current synthesizer generates the bias current. Once the feedback voltage is decreased lower than the threshold voltage, the bias current is reduced linearly and the off-time of the switching period is increased gradually. When the supply voltage is lower than the limit voltage, the bias current increases and determines a maximum off-time of the switching period. The maximum on-time and off-time of the switching period determines the PWM frequency. As the limit voltage varies in every switching cycle, the frequency spectrum of PWM signal spreads in light-load and no-load conditions; and therefore, the acoustic noise is suppressed. The feedback voltage and the supply voltage determine the switching period of the PWM signal. The maximum on-time is kept constant and the switching period is increased by increasing the off-time, such that the magnetic components, such as inductors and transformers, are prevented from being saturated.

Abstract: In regenerative braking mode, an inverter converts, according to PWMC signal from a control unit, an AC voltage generated by a motor into a DC voltage to supply the converted DC voltage to an up-converter which down-converts the DC voltage to charge a DC power supply. The control unit receives voltage V2 from a voltage sensor to stop the up-converter if voltage V2 is higher than a predetermined value. The control unit further receives voltage Vf from a voltage sensor that is applied to a DC/DC converter and stops the up-converter if voltage Vf is higher than a predetermined value. Moreover, the control unit receives voltage V1 of the DC power supply from a voltage sensor to stop the up-converter if voltage V1 does not match voltage V2.

Abstract: Disclosed are a power supplying apparatus and a LCD having the same that reduces manufacturing cost of a large-scale LCD module and enhances powpower efficiency by integrating an external dc power supply used in a large-scale LCD panel into a LCD panel. A first voltage converter converts an external ac voltage into a first dc voltage, and changes a voltage level of the first de voltage into a second dc voltage having a highr voltage level than that of the first de voltage. A second voltage converter converts the second dc voltage into an ac voltage, raises a voltage level of the converted ac voltage, and provides the raised ac voltage to a load. A current detector detects a current flowing through the load, and provides a current detection signal as a feedback signal to the first voltage converter so that the first voltage provide a constant direct current output voltage.

Abstract: A PWM controller having a saw-limiter for power limit without input voltage sensing. The saw-limiter has an adder, a reference voltage, a scaler and a saw-tooth signal that is generated by the PWM oscillator. The saw-limiter produces a saw-limited voltage. The PWM controller will turn off its output when the current-sense input signal of the PWM controller is higher than the saw-limited voltage. The saw-limited voltage is equal to the reference voltage while a PWM switching period starts. After that, the amplitude of the saw-limited voltage will gradually increase until it reaches its maximum voltage. Subsequently, a saw-tooth like waveform is generated for the saw-limited voltage. The slope of the current-sense input signal is proportional to the line voltage. Therefore, a higher line voltage creates a sharp slope for the current-sense input signal, which will be restricted by a lower saw-limited voltage and produces a shorter PWM signal. The PWM signal will be turned off once the voltage of the current sense input signal is higher than the saw limited voltage. In terms of power limit, using the saw-limiter the power limit will be lower when the line voltage is higher. By properly selecting the value of the scaler an identical output power limit for the low line and high line voltage input can be achieved.

Abstract: A voltage controller ( 150 ), the controller comprising: a voltage comparator ( 700 ) operative to provide a digital error signal ( 152 ); a compensator ( 300 ) operative to determine a digital control signal ( 154 ) based on said provided error signal; and a modulator ( 400 ) operative to provide a power control signal ( 156 ) based on said determined digital control signal, wherein said comparator, said compensator, and said modulator are implemented entirely with digital logic gates.

Abstract: In general, three-phase PWM AC/DC power converters have been implemented in the synchronous frame model to eliminate steady state errors effectively and to obtain fast transient response characteristics. However, controllers designed in such way would have input current harmonics and DC-link voltage ripples under the unbalanced input voltage conditions due to the assumption of the balanced input voltage conditions. This paper describes a new control scheme to minimize harmonic distortions of the input current and DC-link voltage in the converter under the unbalanced input voltage. conditions. The synchronous frame input voltage, which is considered as the input side back-EMF component, is regulated pertinently according to the input voltage conditions. The current command is selected to eliminate the reactive power and the second order harmonic component of active power. In this case, the analysis of the input voltage is implemented in the synchronous frame without detecting the phase angle and magnitude of each phase voltage. The proposed control scheme is simple and effectively minimizing the harmonic distortions in the input and output system under the unbalanced input voltage conditions.

Abstract: A voltage measuring circuit (2) of a battery pack comprising at least one or more battery blocks each composed of battery modules connected in series. Voltage measuring lines (21 to 26) are led from voltage measuring points (V1 to V6) of the battery pack (1), one voltage measuring line (23) is grounded, and the other non-grounded voltage measuring line are connected to the grounded voltage detection wire (23) via voltage branch lines (31 to 35). A voltage division resistor is interposed in each non-grounded voltage measuring line and each voltage branch wire, and each non-grounded voltage measuring line is connected to an operation circuit (5) via an analog-digital converter (4). The operation circuit (5) calculate the voltage of each battery module based on voltage measurement data input from each non-grounded voltage measuring line. The number of parts can be reduced, the voltage measurement accuracy can be improved, and disconnection can be reliably detected thereby.

Abstract: PROBLEM TO BE SOLVED: To provide an apparatus for converting a voltage for converting a DC voltage into an output voltage so that the output voltage becomes a voltage command value, even when a boosted output voltage is changed. SOLUTION: A control unit 30 receives the output voltage V2 of a boost converter 12 from a voltage sensor 13, calculates errors in the voltage command from the voltage V2, and regulates a PI control gain (proportionality gain and integration gain), in response to the calculated mistake. The unit 30 feedback controls by using the regulated PI control gain, and the converter 12 converts the DC voltage output from a DC current power source B into the voltage V2 so that the voltage V2 becomes the voltage command. COPYRIGHT: (C)2004,JPO

Abstract: Highly automated production processes are particularly susceptible to voltage disturbances in the power system. Series compensation in the form of dynamic voltage restorer (DVR) is used to mitigate these voltage disturbances. The compensation capability of a particular DVR topology depends on its voltage injection ability and maximum energy storage. This paper presents a new DVR circuit topology which has the ability to mitigate long duration voltage sags with comparatively small energy storage capacitors. The proposed DVR is equipped with a line-side current forced reversible rectifier that helps to maintain the DC-link voltage under voltage sag conditions. A closed loop controller that consists of an inner current loop and an outer voltage loop has been incorporated into the DVR inverter to maintain the load voltage at a desired level. Simulation and experimental results are presented to demonstrate the efficacy of proposed DVR multiloop controller for various voltage sags.

Abstract: An active antenna power interface circuit couples a supply voltage from a radio receiver to an antenna feed. The circuit comprises a DC power input and a power switching element connected in series between the DC power input and the antenna feed. The power switching element has a control input for selecting a conducting state or a nonconducting state of the power switching element. A high side voltage sensor senses a first voltage proportional to a voltage at the DC power input. A low side voltage sensor senses a second voltage proportional to a voltage at the antenna feed. A controller is coupled to the control input and to the voltage sensors. The controller places the power switching element into the conducting state, samples the first and second voltages, calculates a voltage difference in response to the first and second voltages, compares the voltage difference to an upper limit and a lower limit. If the voltage difference is greater than the upper limit then the controller signals a short-circuit fault. If the voltage difference is less than the lower limit then the controller signals an open-circuit fault.

Abstract: A voltage regulator is described, the output voltage of which depends on a drive to a transistor contained in the voltage regulator. The voltage regulator described is distinguished by the fact that it contains a stabilization circuit that can change the current flowing through the transistor. Such a voltage regulator is simple to configure and to implement and, with minimum intrinsic power requirement, is stable under all circumstances.

Abstract: An electric motor drive controller for an electric vehicle driven by a motor with permanent excitation and powered by an energy source comprises: a power control stage coupleable to the motor for generating a drive signal at a voltage to control the motor at a desired speed; a voltage control circuit connectable between the energy source and the power control stage for controlling the voltage of the drive signal at a first voltage potential in one operating mode and at a voltage potential greater than the first voltage potential in another operating mode; and a mode controller for controlling the operating modes of the voltage control circuit based on properties of the drive signal.

Abstract: A system for controlling a brushless direct current (BLDC) motor includes a power supply having a controllably alterable voltage output, and a controller in electrical communication with the power supply and the motor. The controller receives the voltage output of the power supply and can provide a pulse-width-modulated input voltage to the motor. Additionally, the controller can measure an average input current to the motor and a speed of the motor and thereafter alter the voltage output of the power supply based upon the average input current to the motor and the speed of the motor. In a further embodiment, the system can include an acoustic coating disposed about an outer surface of the motor and the controller.

Abstract: A calibration circuitry includes an adjustable capacitor, a voltage generator, a reference voltage generator, and a controller. The reference voltage generator provides a reference voltage. The voltage generator provides a measurement voltage that depends on the capacitance of the adjustable capacitor. The capacitance of the adjustable capacitor varies in response to a control signal. The controller provides the control signal based on the relative values of the reference voltage and the measurement voltage.

Abstract: A low-noise current reference circuitry includes a voltage source, a current source, and a controller. The voltage source generates a reference voltage. The current source provides a low-noise output current in response to a control signal. The controller provides the control signal based at least in part on the relative magnitudes of the reference voltage and a voltage derived from the output current. A low-noise voltage reference circuitry includes a reference voltage source, a voltage source, and a controller. The reference voltage source generates a reference voltage. The voltage source provides a low-noise output voltage in response to a control signal. The controller provides the control signal based at least in part on the relative magnitudes of the output voltage and the reference voltage.

Abstract: A system ( 10 ) regulates current and voltage in a power system by using a correction signal that is modified to compensate for errors associated with manufacturing variations. The correction signal controls a power switch ( 49 ) that selectively sources/shunts current to/from the output load ( 26 ) and power source. The compensation technique applies to systems conducting either an A.C. or a D.C. voltage. A current controller ( 44 ) is placed in a control loop. The current controller contains circuitry having an offset voltage and loop gain errors as a result of manufacturing variations. At least one of the offset voltage and loop gain are dynamically calculated by a loop controller ( 38 ) and the result is used to modify the correction signal to provide an accurate output load voltage and power line current.

Abstract: A method and apparatus for supplying power to a load. The apparatus comprising a voltage regulator circuit and a controller coupled to the voltage regulator circuit. The controller to cause the voltage regulator circuit to maintain a first voltage for the load operating in the first mode. The controller to detect a change in the operating mode of the load and to cause the voltage regulator circuit to output a second voltage. Prior to causing the voltage regulator circuit to output a second voltage the controller may allow voltage and current to stabilize at the load at a value between the first mode and a second mode.

Abstract: PROBLEM TO BE SOLVED: To provide a small drive voltage controller that can be driven with low power consumption. SOLUTION: This drive voltage controller is provided with an operational amplifier OPVcomH for an H side output and an operational amplifier OPVcomL for an L side output for supplying drive voltages VcomH and VcomL to a load such as a liquid crystal display panel, an output switch 101 for switching outputs of the respective operational amplifiers OPVcomH and OPVcomL at prescribed timing, a set voltage generating part 103 for generating a set voltage VrefL to be supplied to a noninverted input terminal of the operational amplifier OPVcomL for an L side output and having an operational amplifier OPVref for L voltage setting, a current mirror circuit 151 and a clamping circuit 153, a bias current control part 105 for controlling bias currents of the respective operational amplifiers OPVcomH and OPVcomL at prescribed timing, and a timing control part 107 for controlling switching timing of the output switch 101. COPYRIGHT: (C)2003,JPO

Abstract: Requirements on the power quality of AC sources are becoming more stringent as more voltage-sensitive equipments are being used. Among the power quality deterioration issues, voltage unbalance and voltage fluctuations are two serious ones. An active voltage regulator, which is used as a part of unified power quality conditioner (UPQC), is proposed to compensate for the voltage unbalance and fluctuations in this paper. It is composed of a voltage source inverter (VSI) coupled in series with the supply through transformers. The adopted topology guarantees that the energy can flow bi-directionally, thus it can regulate the load voltage to the expected value during long-drawn supply voltage fluctuation. Another aspect covered in this paper is the synchronization problem or the technique to get the phase angle of the reference signal, which is essential in voltage regulation. A software synchronization based on a new fundamental positive sequence (FPS) component extraction method is presented and proven in the paper. The active voltage regulator with the proposed topology and the synchronization method features in no hardware synchronization requirement, accurate and fast phase tracking and high dynamic performance. Experimental results performed on the prototype testify the validity of the proposed active voltage regulator in voltage unbalance and fluctuation compensation.

Abstract: A battery charging method and system, the battery charging method comprising: charging at least one battery at a first voltage for a first voltage for a first time duration; charging the batteries (222) at a second voltage for a second voltage for a second time duration; determining state of charge of the batteries at the end of the second time duration; if the batteries are not substantially fully charged at the end of the second time duration, the total charging time is evaluated to determine if the batteries have been charged for a time duration greater than or equal to a third time duration, and id the total charging time has not exceeded or is not equal to the third time duration, charging the batteries at the first voltage for the first time duration and charging the batteries at the second voltage for the second time duration is repeated. The battery charging system (211) comprises: a current source; a cutoff voltage controller and timer; at least one battery; respective ones of voltage and current regulators; and a system voltage and current regulator (217), which shunts current from the batteries.

Abstract: PROBLEM TO BE SOLVED: To provide an image forming apparatus that controls power consumption, while maintaining image quality without the image defects due to negative afterimage, and that can attain energy savings. SOLUTION: A transfer voltage controller of a transfer device begins to apply the transfer voltage to a first transfer roller 11, prior to the arrival of a latent image region front end Is at the entrance of a transfer nip, wherein the latent image region front end Is is the front end of a latent image forming region Ai on the surface of a photoreceptor, where a latent image is formed on the latent image forming section. Furthermore, the transfer voltage controller controls transfer power supply, to stop applying the transfer voltage to the first transfer roller after a latent image region rear end Ie passes through the exit of the transfer nip, wherein the latent image region rear end Ie is the rear end of the latent image forming region Ai, and a discharge device begins a discharge operation, while the transfer power supply applies the transfer voltage to the first transfer roller 11 before a voltage application exit V1 arrives at the discharge nip, where the voltage application exit V1 is the front end of a transfer voltage applying region Av on the surface of a photoreceptor that has passed through the transfer nip. Furthermore, the discharge device stops discharge operation, after a voltage shut-down exit Ve passes through the discharge nip, where the voltage shut-down exit Ve is the rear end of the a transfer voltage applying region Av. COPYRIGHT: (C)2008,JPO&INPIT

Abstract: An excitation controller for a synchronous machine includes: a voltage detector for detecting an output terminal voltage of the synchronous machine connected to a transmission system through a transformer; a current detector for detecting a current outputted by the synchronous machine; a module type HSVC apparatus for operating arithmetically a reactive current value on the basis of output from the voltage detector and the current detector, operating arithmetically a high side voltage value from the reactive current value thus arithmetically operated and a reactance of the transformer and outputting a correction signal based on a deviation between the high side voltage value thus arithmetically operated and a voltage setting value; an automatic voltage regulator, having a voltage setter, for outputting a command which is obtained by adding the correction signal to a voltage setting value provided by the voltage setter; and an exciter for carrying out field control of the synchronous machine on the basis of the command issued from the automatic voltage regulator.