994 results about "Dropout voltage" patented technology

An electronic cigarette, cigar or pipe has a capacitor sensor includings a first conductive plate and a second conductive plate configured to form a capacitor circuit. An output of the capacitor sensor is based at least in part on the capacitance of the capacitor circuit. A pressure sensitive component is connected to the first conductive plate and configured to move the first conductive plate based on a pressure differential between two sides of the pressure sensitive component to change a capacitance of the capacitor circuit.

A voltage regulator includes first and second closed-loop amplifiers and a N-type transistor. The first amplifier receives a first reference voltage and a feedback voltage. The second amplifier is responsive to the first amplifier and to the regulated output voltage of the regulator. Both amplifiers are biased by a biasing voltage. The second amplifier has a bandwidth greater than the bandwidth of the first amplifier and a gain smaller that the gain of the first amplifier. The N-type transistor has a first terminal responsive to the output of the second amplifier, a second terminal that receives the input voltage being regulated, and a third terminal that supplies the regulated output voltage. The feedback voltage is generating by dividing the regulated output voltage. An optional fixed or dynamically biased current source biases the first terminal of the N-type transistor. The voltage regulator optionally includes an overshoot correction circuit.

A furnace filter indicator system comprises a pressure differential switch that monitors air pressure near a furnace filter, and a transmitter coupled to the pressure differential switch sends a signal to a receiver within a thermostat. The receiver includes an indicator for indicating the status of the furnace filter. If the pressure differential near the furnace filter triggers the switch, then the indicator will receive a “dirty” signal and will indicate that the furnace filter is dirty and should be replaced. The furnace filter indicator system is able to be installed on a previously installed furnace / thermostat system by utilizing the pre-existing wiring.

The application discloses a pixel circuit and a display device. The pixel circuit comprises a storage capacitor, a third transistor, a second transistor and a light-emitting branch used for connecting in series between a first common electrode and a second common electrode, and the light-emitting branch comprises a fifth transistor, a driving transistor, a sixth transistor and a light-emitting element which are connected in series. In an initialization stage, the third transistor and the fifth transistor conduct and initialize the potentials at the two ends of the storage capacitor, in a programming stage, the second transistor inputs a data signal to one end of the storage capacitor via the third transistor and stores, and in an luminescence stage, the driving transistor drives the light-emitting element to emit light according to the voltage difference at the two ends of the storage capacitor. By the pixel circuit and the display device, the threshold voltage of the driving transistor and the degeneration of the light-emitting element can be compensated, at the same time, the contrast of a display also can be increased.

The invention relates to an LED driver with an adjustable conduction time. The LED driver with the adjustable conduction time comprises one way or multiple ways of LEDs, a conductive threshold value setting module and a controlling module, wherein the LEDs are conducted when power supply voltage rises to LED conduction voltage, the conductive threshold value setting module is used for setting the LED conductive time, and the controlling module is used for disconnecting the one way or the multiple ways of LEDs when the power supply voltage rises to exceed an LED conduction voltage setting threshold value, and connecting the one way or the multiple ways of LEDs when the power supply voltage reduces to exceed the LED conduction voltage setting threshold value according to the conduction time of the LEDs, wherein the setting threshold value is related to the LED conduction threshold value. Due to comparison of an input voltage and an LED voltage drop, conduction time of the LEDs is controlled, the problem that voltage differences of the input voltage and the LED voltage are too large is solved, efficiency of a linear LED driving circuit is improved, circuit heating value is reduced, and application reliability is enhanced. In addition, the LED driver with the adjustable conduction time flexibly achieves the compromising design of high efficiency of the linear controlling scheme and a PF value through controlling the LED conduction time.

The invention relates to an energy transfer type power battery quick balancing system and a control method thereof. The invention relates to the battery voltage balancing system and further relates to the control method of battery pack quick balancing process, which solves the problem that a balanced battery single body and an energy storing element are impacted through pulse current by a currentbalancer in the prior art. The system comprises a power battery pack single body battery voltage and flying capacitor voltage detecting network, a current sensor and a signal modulating circuit, a single chip microcomputer, an electric power transfer channel, a first filter circuit, a two-way buck-boost converter, a second filter circuit and a flying capacitor. After starting to work, the system firstly detects the battery pack single body battery voltage, the flying capacitor voltage and the charging / discharging current; and if the dropout voltage between the highest voltage of the battery single body and the lowest voltage of the single body exceeds a set value, the balancing operation is started.

The invention relates to an intelligent power lithium ion battery management system. The system comprises a microcontroller module, an acquisition module, a storage module, a safety protection module, a communication module, a charging and discharging control module and an equalization management module, wherein the acquisition module, the storage module, the safety protection module, the communication module, the charging and discharging control module and the equalization management module are connected to the microcontroller module. The charging method comprises the following steps that according to a single battery voltage collected by the acquisition module, a total voltage of a battery pack, a temperature, a current and other information, whether the battery allows to be charged is determined; if the battery allows to be charged, the battery management system automatically adjusts a charging mode to the battery pack; through CAN communication, an output current of an equalization power supply module is automatically adjusted; equalization charging is performed on a single battery with a low voltage till that differential voltages of all the single batteries are less than a threshold. By using the system and the method of the invention, according to data information of the battery pack, a charging mode can be automatically selected, a charging current is automatically matched, a charging protection function is possessed, charging efficiency of the battery pack can be increased and a circulation service life of the battery pack is prolonged.

The invention provides light modulating control circuit, chip and method. The light modulating control circuit is suitable for being connected with a light modulator for controlling a light-emitting device. The light modulating control circuit comprises a boosting control module, a constant current control module and a light modulating control module, wherein the boosting control module is used for boosting the input voltage of the light modulating control circuit and maintaining a voltage difference of the output voltage and the input voltage of the light modulating control circuit in a certain range so as to maintain the synchronization of the voltage at both ends of the light modulator and current passing through the light modulator; the constant current control module is used for maintaining the stability of the output current of the light modulating control circuit when the light modulating signal is not changed; and the light modulating control module is used for changing the output current of the light modulating control circuit according to the change of the light modulating signal of the light modulator. The light modulating control circuit, chip and method provided by the invention can ensure that the light modulator normally works and realizes effective adjustment on an illuminating device.

The invention belongs to the technical field of integrated circuits and specifically relates to a high mains rejection ratio low dropout voltage linear voltage regulator with a feedforward transconductance, which consists of an error amplifier, a buffer, a PMOS pass transistor, a feedforward transconductance, two feedback resistors and a filter capacitor, wherein the error amplifier is a current mirror amplifier consisting of a tail current source, a PMOS input differential pair and three groups of current mirrors. The mains voltage fluctuation influences the output mainly via two paths of the PMOS pass transistor and the parasitic resistor of and PMOS pass transistor. The feedforward transconductance transforms the perturbation of the mains voltage into the perturbation of the current, and then the perturbation of the current is transformed into the in-phase voltage perturbation of the grid of the pass transistor via the parasitic resistor of the error amplifier. The influence of the mains voltage perturbation on the output can be eliminated by the control of the gain of the feedforward transconductance so as to realize high mains rejection ratio. The invention can optimize the mains rejection ratio within a wider range of load current and does not reduce the efficiency of the low dropout voltage linear voltage regulator.

An electronic control system for regulating operational parameters in a pollution removal system. The pollution removal system may contain at least one reaction zone connected to a source of gas and a sorbent feeder containing a supply of sorbent. The system may include a pollutant concentration sensor that measures the concentration of at least one target pollutant in a gas exiting a reaction zone, a differential pressure sensor that measures the differential pressure across a reaction zone, a sorbent feed rate controller that regulates sorbent feed rate to the reaction zone, and a controller in communication with these elements. The controller may use the measured values to adjust sorbent feeder rate to ensure that the target pollutant concentration in a gas exiting the reaction zone is within an acceptable range and that differential pressure across the reaction zone is no greater than a predetermined level.

The invention relates to a ground wire safety voltage control system which comprises a power supply circuit, a detection circuit, a processing circuit and an output circuit, wherein the output circuit is connected with an interruption device with a load in a connecting manner, the power supply circuit is connected between a live wire and a zero wire and used for providing a power supply for a control system; the detection circuit is used for detecting a ground wire voltage and outputting a control signal to the processing circuit when the voltage difference between the ground wire voltage and the zero wire voltage reaches a preset safety voltage range; and the processing circuit is used for processing the ground wire voltage according to the control signal and controlling the output circuit to trigger the external interruption device to interrupt to switch off the connection between the power supply and the load. When detecting that the ground wire voltage reaches a preset range or the zero wire and the live wire are connected inversely, the detection circuit triggers a leakage protection plug to trip and alarm through the processing circuit and the output circuit, the connection between the power supply and the load is switched off, thus the purpose of preventing fire or electric shock is achieved and the use safety of electricity-consuming products is enhanced.

A voltage regulator circuit includes a digital control block, an amplifier and a transistor. The digital control block receives a first reference voltage and a feedback voltage, converts the received voltages from analog to digital signals, performs an integration operation on the converted signals, and converts the result of the integration operation to an analog signal. The amplifier is responsive to the output of the digital control block and to a regulated output voltage of the regulator circuit. The transistor has a first terminal responsive to the output of the amplifier, a second terminal that receives the input voltage being regulated, and a third terminal that supplies the regulated output voltage. The transistor may be an NMOS or a bipolar NPN transistor. The feedback voltage may be generated by dividing the regulated output voltage. The digital control block optionally generates a biasing signal to bias the amplifier.

A low-dropout (LDO) voltage regulator for generating an output voltage is disclosed. The voltage regulator includes a startup circuit, a curvature corrected bandgap circuit, an error amplifier, a metal oxide semiconductor (MOS) pass device and a voltage slew rate efficient transient response boost circuit. The MOS pass device has a gate node which is coupled to the output of the error amplifier, and a drain node for generating the output voltage. The voltage slew rate efficient transient response boost circuit applies a voltage to the gate node of the MOS pass device to accelerate the response time of the error amplifier in enabling the LDO voltage regulator to reach its final regulated output voltage when an output voltage drop occurs in the LDO voltage regulator.

The invention discloses a circuit for a multi-path LED constant current driving, comprising a DC / AC converting circuit, a main transformer, a current sharing transformer, a multi-path rectification filter circuit and LED loads, the circuit for the multi-path LED constant current driving is characterized in that: the input direct voltage is converted into alternating voltage by the DC / AC converting circuit, the alternating voltage is isolated by the main transformer and then is input to the current sharing transformer, the current sharing transformer has the function of current sharing for each path of the current, and each path of the current is respectively output to each LED load after passing through each rectification filter circuit. The circuit for the multi-path LED constant current driver has the beneficial effects that: firstly, the balance of load current among multi-path LEDs is realized by a first level converting circuit; secondly, the current sharing control is automatically realized by the current sharing transformer without an extra control circuit, the reliability is high; thirdly, the efficiency of realizing current sharing is high by the current sharing transformer, the loss of realizing current sharing is less when the dropout voltage of two paths of the LEDs is high.

The invention discloses an organic light emitting diode display device, which comprises a gate driver, a source driver, a plurality of pixel units and a plurality of infrared units, wherein the gate driver is used for generating a scanning signal; the source driver is used for generating a data signal; each pixel unit comprises a first transistor, a drive circuit and an organic light emitting diode; each infrared unit comprises an infrared light emitting area and an infrared light sensing area; the first transistor is used for conducting the data signal when receiving the scanning signal; the drive circuit is used for generating drive current according to a voltage difference between a power signal and the data signal; the organic light emitting diode is used for generating light rays according to the drive current; the infrared light emitting area is used for emitting infrared rays; and the infrared light sensing area is used for sensing the infrared rays reflected by a reflector.

An embodiment of the invention discloses a thin film transistor liquid crystal display panel, which comprises multiple scanning lines, multiple data lines, and multiple pixel units; multiple scanninglines are extended along the first direction, and multiple data lines are extended along the second direction which is perpendicular to the first direction; every pixel unit comprises a red sub-pixel,a green sub-pixel, a blue sub-pixel and a white sub-pixel; the sub-pixel is electrically connected with the scanning line and the data line, and every sub-pixel comprises a main pixel electrode and asecondary pixel electrode; when the data line inputs the same data signal to the sub-pixel, the pressure difference between the main pixel electrode and the secondary pixel electrode in the red sub-pixel, the blued sub-pixel and the green sub-pixel is more than the pressure difference between the main pixel electrode and the secondary pixel electrode in the white sub-pixel. The embodiment of theinvention further provides a liquid crystal displayer. By adopting the invention, the color cast of the thin film transistor liquid crystal display panel when it has a great visual angle can be improved.

The invention provides a low dropout voltage regulator which improving characteristics of line and load regulation, comprising a reference voltage circuit, a differential amplifier, an output power transistor, a feedback circuit and a voltage buffer, wherein the reference voltage circuit is used to provide reference voltage; the output power transistor is used to drive a load resistor; the feedback circuit is arranged between the differential amplifier and the output power transistor to make the differential amplifier compare the reference voltage with voltage provided by the feedback circuit and output error correction voltage; the voltage buffer is arranged between the differential amplifier and the output power transistor for carrying out the function of frequency compensation, and is formed by a complementary buffer. The low dropout voltage regulator can provide excellent line and load regulation.

A low dropout (LDO) voltage regulator having more than one LDO modules, each LDO module having a frequency response adapted to a certain range of output frequency. The LDO voltage regulator can provide a gain over a broad range of operating frequency by combining output current from each LDO module and providing the combined current at an output of the LDO voltage regulator. The LDO voltage regulator further comprises a load monitor coupled to the LDO modules for disabling some of the LDO modules to reduce power consumption of the LDO voltage regulator.

A cylindrical pump baffle fitted to a semiconductor processing chamber is disclosed. The pump baffle contains a screen with bores therethrough to allow process gasses from the process chamber to be exhausted from the chamber at a reduced rate. This decreases process discrepancies to the wafer due to the prejudice of gas concentration as a result of the pressure differential imposed upon the gas and thereby the wafer brought about by the rapid and relatively unimpeded exit flow of process gasses when no restrictive member is in place. The pump baffle is also machined such that it does not block the placement and removal of wafers by the platform robot arm.

The invention provides a high-accuracy low-dropout voltage regulator which comprises an output tube, a voltage division circuit, a current source, an adjustable resistor string, an error amplifier and an imbalance calibration circuit. The current source and the adjustable resistor string are sequentially connected between input voltage and the ground. The adjustable resistor string comprises a plurality of trimming resistors sequentially connected in series and a plurality of trimming switches in parallel connection with the trimming resistors. The first input end of the error amplifier is connected with the current source and the middle node of the adjustable resistor string, the second input end of the error amplifier receives feedback voltage obtained by the voltage division circuit, and the output end of the error amplifier is connected with the control end of the output tube. The first input end of the imbalance calibration circuit receives reference voltage, the second input end of the imbalance calibration circuit receives the feedback voltage, and the output end of the imbalance calibration circuit is connected with the control ends of the trimming switches. The imbalance calibration circuit outputs calibration data to the control ends of the trimming switches so as to enable the feedback voltage to be locked in a reference voltage based locking range. Therefore, the influence brought by environmental temperature, environmental humidity and package situation can be made up.

The invention discloses a self-adapting current multiplication circuit and a low-dropout-voltage linear voltage regulator integrating the circuit. Firstly, constant bias voltage of an NMOS transistor and constant bias voltage of a PMOS transistor are generated through a constant bias voltage generating circuit, and then a lagging current comparator collects small part of load current which is compared with constant current; when a load is in a light load, the lagging current comparator shuts off a self-adapting current multiplication generating circuit, self-adapting current multiplication voltage VBPA rises, the bias current of an operational amplifier of the low-dropout-voltage linear voltage regulator lowers, in this way, stability is guaranteed, and quiescent dissipation is reduced; when the load is in a heavy load from a moderate load, the lagging current comparator turns on the self-adapting current multiplication generating circuit, the self-adapting current multiplication voltage VBPA lowers, the bias current of the operational amplifier increases to the specific times the bias current of the operational amplifier during the light load, the gain bandwidth product of the low-dropout-voltage linear voltage regulator increases, and transient response performance is enhanced.

A voltage regulator with output accelerated recovery circuit is disclosed, which is substantially a low dropout voltage regulator (LDO) having a comparator and a pull-down transistor, both being connected between the positive feedback input node of its operational amplifier (OP) and the ground end thereof. In a preferred aspect, the comparator is used for detecting the voltage variation of a reference node, whereas the reference node is defined to be a node located between a first feedback resistor and a second feedback resistor. Operationally, as the voltage detected at the reference node is larger than a predetermined voltage, the pull-down transistor is forced to turn on so as to sink the output voltage rapidly for returning the same back into regulation.

The invention belongs to the technical field of power supply, in particular to a dual-mode fully-integrated high-frequency reduction voltage power supply with the high light load efficiency, which consists of a control circuit, a power tube, an integrated inductor and a filter capacitor, wherein the control circuit consists of an error amplifier, a sawtooth generator, a soft start circuit, a comparator, a compensation circuit, a driving and dead band control circuit, a high-frequency current detection circuit, a low-dropout voltage linear voltage regulator detection circuit, a mode control module and a low-dropout voltage linear voltage regulator. In the dual-mode fully-integrated high-frequency reduction voltage power supply, load current is judged, and the optimal operating mode is selected to improve the operating efficiency of the power supply and reduce a peripheral circuit and cost; in addition, the high-frequency characteristic of the power supply also can meet the requirement of load change.

A DC / DC converter has a linear voltage regulator for reducing or eliminating the output ripple of the converter with a minimum loss of efficiency. The converter comprises a converter stage with a supply voltage input, a converted voltage output and a control input, a regulator stage having an input connected to the converted voltage output of the converter stage and an output connected to a load, and a tracking circuit with inputs for a voltage at the converted voltage output of the converter stage, a voltage at the output of the regulator stage and a load sense current, and an output connected to the control input of the converter stage. The tracking circuit controls the converter stage so as to increase the converted voltage with an increasing load sense current and vice versa. The output voltage of the converter is always just sufficient to eliminate the ripple without having to operate the regulator's pass transistor in its linear range.

The invention is concerned with circuit control field to afford a kind of switch control equipment for main backup power. The main switch and control unit controls the open and close to power supply circuit of main electrical source, according to the press different of pressure of main electrical source and export pressure of combined way. The backup switch and control unit controls the open and close to backup electrical source gateway, according to the press different of pressure of main electrical source and reference pressure. The said main switch and control unit and backup switch and control unit each owns one low dropout switch components. It takes active switch as switch component of main backup electrical source to advance action of switch and reduce voltage drop and waste. It is fit for low press circuit to realize the same insulation action as a diode. It realizes the uninterruptible switch of two electrical sources, improves the dependability of system and the radiating of all components is easy.

The invention relates to a ground condcutive water cut analyzer for measuring water cut in oilfield export liquor. It is characterized by that the described analyzer includes an electric conductance sensor, excitation source generation circuit, voltage differential signal detection and voltage / frequency signal covnersion circuit. The described electric conductance sensor is formed from insulating tube, ring excitation, electrode mounted on the inner wall of insulating tube and ring measurnig electrode. Under the action of excitationsource generation circuit the excitation electrode can provide alternating current with constant magneitude, and under the action of voltage / frequency converter the pressure-different signal inputted by measuring electrode can be converted into frequency signal and outputted, then passed through power amplifier and transferred into secondary meter. Its measurement accuracy is high, repeatability and good consistency.

The invention discloses an LED (light emitting diode) backlight driving method, a liquid crystal display device and an LED backlight driving circuit. The LED backlight driving method comprises the following steps of: adjusting the size of currents of LED strings so that the voltages of all the LED strings are equal; and adjusting the current duty ratio of the corresponding LED strings so that thecurrent effective value of each LED string reaches the brightness requirement. According to the invention, the voltages of all the LED strings are kept equal through adjusting the size of currents bya current adjustment module, therefore, the problem of loss caused by voltage difference can be solved; the current effective values of all the LED strings are kept equal through adjusting duty ratioof a duty ratio adjustment module, therefore, the brightness consistency is ensured.

The invention discloses a PWM (Pulse-Width Modulation) controller which comprises an error amplifier, a PWN comparator, a slope compensation current generating circuit, a clamping circuit and a slope compensation superposed circuit. In the PWM controller, the clamping circuit is introduced so that a high-end clamping point output by the error amplifier synchronously changes along with a slope compensation signal and an inductance current peak value is maintained to be unchanged, and thus the problem that the duty ratio affects a peak value current limit is solved, a constant current limit is ensured and the whole system works normally; and a relative earth potential concept is introduced by adding a relative earth potential generating circuit into the PWM comparator, so as to reduce voltage difference between power supply voltages, thus a high-performance high-speed PWM controller can be realized by use of low voltage components.