2151 results about "Voltage compensation" patented technology

A voltage compensation unit reduces the effects of induced voltages upon a device having a single wire line. The single wire line has balanced characteristic impedance. The voltage compensation unit includes a tunable compensation circuit connected to the wire line. The tunable compensation circuit applies supplemental impedance to the wire line. The supplemental impedance causes the characteristic impedance of the wire line to become unbalanced, thereby reducing the effects of induced voltages caused by changing magnetic fields.

A pixel having a structure in which low voltage drive is possible is provided by a simple process. A digital image signal input from a source signal line is input to the pixel through a switching TFT. At this point, a voltage compensation circuit amplifies the voltage amplitude of the digital image signal or transforms the amplitude, and applies the result to a gate electrode of a driver TFT. On-off control of TFTs within the pixel can thus be performed normally even if the voltage of a power source for driving gate signal lines becomes lower.

The present invention may be regarded as a disk drive comprising a disk, a head, an actuator arm for actuating the head radially over the disk, and a voice coil motor (VCM) for rotating the actuator arm about a pivot, the VCM comprising a coil comprising a VCM resistance R. A back EMF voltage detector measures a back EMF voltage across the coil, and a current detector detects a current I flowing through the coil. An IR voltage detector, responsive to the current I detected by the current detector, detects an IR voltage proportional to the current I times the VCM resistance R. A voltage compensator substantially cancels the IR voltage from the measured back EMF voltage to generate a compensated back EMF voltage. A control voltage generator, responsive the compensated back EMF voltage, generates a control voltage applied to the coil to generate the current I flowing through the coil. A stall detector compares the current I detected by the current detector to a threshold, wherein a VCM stall condition is detected if the current I exceeds the threshold for a predetermined interval.

A voltage compensation unit reduces the effects of induced voltages upon a device having a single wire line. The single wire line has balanced characteristic impedance. The voltage compensation unit includes a tunable compensation circuit connected to the wire line. The tunable compensation circuit applies supplemental impedance to the wire line. The supplemental impedance causes the characteristic impedance of the wire line to become unbalanced, thereby reducing the effects of induced voltages caused by changing magnetic fields.

A power harvesting system including multiple parallel-connected photovoltaic strings, each photovoltaic string includes a series-connection of photovoltaic panels. Multiple voltage-compensation circuits may be connected in series respectively with the photovoltaic strings. The voltage-compensation circuits may be configured to provide respective compensation voltages to the photovoltaic strings to maximize power harvested from the photovoltaic strings. The voltage-compensation circuits may be include respective inputs which may be connected to a source of power and respective outputs which may be connected in series with the photovoltaic strings.

A liquid crystal display device (LCD) includes a liquid crystal panel having a plurality of gate lines, a plurality of data lines, and a plurality of common voltage supply lines, the liquid crystal panel being divided into a plurality of blocks, a plurality of gate driver integrated circuits (ICs) connected to the plurality of gate lines, a plurality of data driver ICs connected to the plurality of data lines, and a plurality of common voltage compensators to supply compensated common voltages to the common voltage supply lines the corresponding blocks.

The functionality of electronic convertors for low voltage filament lamp applications, such as halogen lamps, can be increased by including auxiliary circuits. Such auxiliary circuits may include gate drive resistors; a charge pump for sustaining the DC supply; open circuit protection; short circuit protection; thermal protection; extended resetting time; latched shutdown; self-dimming; a digital (DALI) interface; and line voltage compensation.

An apparatus and method is provided for adjusting a reference voltage at an output terminal of a floating gate reference voltage generator circuit in order to improve the accuracy of the reference voltage at an input terminal of a load circuit. The apparatus and method compensates for the voltage drop produced between the output terminal of the reference voltage generator circuit and the input terminal of the load circuit, and includes a capacitor for capacitively coupling the voltage at the input terminal of said load circuit to a floating gate, and a differential amplifier operatively coupled to the floating gate which acts in response to the capacitively coupled load circuit input voltage to adjust the voltage at the output terminal such that the voltage at the input terminal of the load circuit becomes equal to the reference voltage.

A liquid crystal display device and a driving method thereof for preventing a brightness difference between horizontal line blocks are disclosed. In the liquid crystal display device, a liquid crystal display panel has a liquid crystal cell matrix. A power supply generates a common voltage. Common lines directly on a substrate of the liquid crystal display panel are connected to a common electrode of the liquid crystal cell. A common voltage compensator compensates for the common voltage into a large resistance value with a resistance value greater than a combination of resistances of the common lines and the large resistance directly between the power supply and the common lines.

In organic emitting diode circuit that is equipped with voltage compensation function and a method for compensating voltage in the organic light emitting diode circuit are presented. The circuit includes a first transistor, a pixel control unit, a precharge control component and an OLED. The present invention OLED presents numerous benefits when compared to conventional OLED such as the present invention OLED can be designed as a common cathode component such that it has improved aperture ratio, it enables array testing of the circuit before the fabrication process is completed, and it allows color and brightness compensation in addition to voltage compensation.

In compensating for unbalanced voltages of three-phase AC, instantaneous values of wye-phase voltages 120° out of phase with each other are obtained from line voltages using a centroid vector operation, symmetrical component voltages of three-phase balanced system are obtained from the instantaneous values of wye-phase voltages, a compensation signal to compensate unbalanced voltages of three-phase AC is generated from zero-phase-sequence voltage of symmetrical component voltages is generated, wye-phase voltages 120° out of phase, the unbalanced voltages of which are compensated, are obtained from the compensation signal and the symmetrical component voltages, a control signal of a PWM conversion is generated based on the compensated wye-phase voltage compensated, and the unbalanced voltages of three-phase AC are compensated. The amount of time to compensate the three-phase unbalanced voltages required for detecting an unbalance of voltages and generating a control signal can be shortened.

A battery cover assembly having integrated battery condition monitoring for measuring electrical current passing to and from a battery post, including an electrically conductive collar for connecting to a post of a battery, and an electrically conductive terminal for receiving a connector of a load. An electrically conductive resistor having a known resistance extends between outer surfaces of the collar and the terminal. The battery cover assembly is incorporated into a battery, which may also include a voltage measuring device connected between the outer surfaces of the collar and the terminal for measuring the voltage drop across the resistor, memory for storing the known resistance of the resistor, and a digital processor programmed to receive the measured voltage drop from the voltage measuring device, retrieve the known resistance from the memory, and calculate current flow through the resistor based on the measured voltage drop and the known resistance, whereby current flow to and from the battery can be measured. A temperature measuring device may also be incorporated to measure temperature of the resistor located between the outer surfaces of the collar and the terminal. A resistance-temperature table may be stored in the memory and used to calculate the actual resistance of the resistor and then to compensate the current value from the voltage measured across the resistor.

The invention discloses a public voltage compensation circuit, a public voltage compensation method and a liquid crystal display (LCD) device, belonging to the display field. According to the public voltage compensation circuit, the public voltage compensation method and the liquid crystal display device,, the compensation accuracy is high, more stable public voltages can be acquired, phenomena such as residual images, abnormal gray scale display, crosstalk and the like caused by public voltage offset can be avoided, and the display effect is improved. The public voltage compensation method comprises the following steps: comparing a feedback voltage with a reference public voltage output by a public voltage generation circuit; generating a compensation control signal according to a comparison result; and according to the compensation control signal, compensating a public voltage. The public voltage compensation circuit comprises a comparison unit, a logic unit and a compensation unit.

A common voltage compensating circuit for a liquid crystal display device includes: a voltage distributing unit outputting a reference voltage; a deviation sensing unit detecting a deviation of a common voltage in a liquid crystal panel and outputting a deviation signal corresponding to the deviation of the common voltage; and a first compensating unit compensating the common voltage and outputting a first compensated common voltage by using the reference voltage, the deviation signal and an output thereof.

The invention provides an OLED display device and a luminance compensation method thereof. The OLED display device is provided with a plurality of detection lines, which are connected to a driving chip. Each detection line is connected to a power supply line arranged on a predetermined position through a plurality of switch elements so as to detect the actual positive power supply voltage of pixel units on the predetermined position. The driving chip obtains a data voltage compensation value of at least part of pixel units according to the detected actual positive power supply voltage and one reference positive power supply voltage, and then provides a data voltage to at least part of pixel units according to the data voltage compensation value so as to improve the luminance uniformity of a whole panel.

A display apparatus includes; a data driver integrated in one chip and which outputs data signals; a gate driver which sequentially outputs gate signals, a display panel which includes; a plurality of data lines which receive the data signals, a plurality of gate lines which receive the gate signals, and a plurality of pixels connected to a corresponding gate line and a corresponding data line, a voltage generator which generates a common voltage and a storage voltage and provides them to the display panel, and a voltage compensator which receives the storage voltage fedback from the display panel and generates a compensation signal, wherein the display panel further includes a feedback line which provides the voltage compensator with the storage voltage, and wherein the feedback line is electrically connected to the voltage compensator through the data driver.

The invention discloses a device and method for achieving external dynamic compensation for display screen active area direct-current voltage drop. The device comprises an input signal comparator, a processor and a voltage signal modulating device. The input signal comparator is used for detecting current or voltage consumption of a current display frame on an ELVDD bus in real time, the detected current or voltage consumption is converted into digital signals which are output to the processor. The processor compares the received digital signals with the stored current or voltage consumption reference value of the current display frame in reference data information, a current or voltage compensation value which needs to conduct compensation on the current display frame is obtained, and the current or voltage compensation value is output to the voltage signal modulating device in a digital mode. The voltage signal modulating device generates an analog-form compensation voltage according to the received current or voltage compensation value and then feeds the compensation voltage back to an ELVDD lead, and the voltage is applied to each pixel unit through an ELVDD bus in an active area, so that external dynamic compensation for the display screen active area direct-current voltage drop is achieved.

A liquid crystal display device includes a timing controller generating a voltage compensation control pulse and a gate control signal, a voltage compensation signal generator generating a voltage compensation signal, the voltage level of which is gradually reduced during one frame period, in response to the voltage compensation control pulse, a power unit outputting a gate-on voltage to a plurality of gate lines by gradually increasing the level of the gate-on voltage in response to the voltage compensation signal, and a gate driver sequentially supplying the gate-on voltage to the plurality of gate lines in response to the gate control signal.

A voltage compensation circuit, a multi-level memory device with the same, and a voltage compensation method for reading the multi-level memory device are provided. When a memory cell is read, a reference voltage applied to the memory device is adjusted according to variation of characteristics of a drift resistance of a reference cell. The increased value of the reference voltage (i.e. a voltage difference) corresponds to a resistance variation caused by a drift condition. The drift compensation mechanism is adaptive to a compensation circuit of a read driver of the memory device, which can compensate variation of the voltage level when data is read from the memory cell. When the resistance drift occurs, a drift amount is calculated and is added to the reference voltage, in order to avoid the error in judgement caused by the resistance drift when the stored data is read out.

The invention discloses a space vector modulation based harmonic current compensation system for a high-speed permanent magnet motor. The system comprises a rotor position and speed observation module, a stator phase current harmonic compensation module, a phase current feedback module, a rotation speed PI adjustment module, a current PI adjustment module and an SVPWM (space vector pulse width modulation) conversion output module. The stator phase current harmonic compensation module comprises a harmonic current extraction module, a proportional controller, a harmonic current adjustment module and a harmonic voltage compensation amount calculation module. The harmonic current extraction module extracts phase current harmonics of a permanent magnet synchronous motor in real time by the aid of an adaptive band-pass filter; the proportional controller adjusts the harmonic current and feeds the harmonic current to a current loop; the harmonic current adjustment module and the harmonic voltage compensation amount calculation module are used for calculating harmonic voltage compensation amount on the basis of a mathematical model of the high-speed permanent magnet motor and feeding back to the voltage loop. By the space vector modulation based harmonic current compensation system for the high-speed permanent magnet motor, voltage compensation amount can be calculated accurately, real-time compensation can be realized, phase current waveforms in operation of the permanent magnet synchronous motor can be improved effectively, torques and rotation speed pulses can be reduced, and accordingly operation efficiency, stability and reliability of the motor can be improved.

The invention provides a pixel circuit and a driving method thereof. The pixel circuit comprises five transistors and two capacitors. The drive method comprises the steps of providing three control signals and grid signals to the pixel circuit respectively; adjusting the enabling state of the above control signals and maintaining the grid signals not to be enabled so as to rest the data of the pixel circuit and obtain the voltage compensation effect; enabling the grid signals so as to enable the pixel circuit to be in a data write-in period; and providing the data voltage to the pixel circuit during the data write-in period so as to change the end-point voltage for driving the transistor of a light-emitting element.