136results about How to "Short stabilization time" patented technology

The selectivity of response of resistive gas sensors to specific gases or vapors is improved by the selection of specified gas-sensitive materials which are not previously known for the applications described, which include detection of hydrocarbons in the presence of CO, H2S, SO2, chlorine, NO2, CO2 (especially in low concentrations), CFC's, ammonia, free oxygen by determination of partial pressures, and numerous organic gases and vapors.

A circuit and a related method to sense the inductor current of CD/DC buck converters have been achieved. The inductor current is sensed by generation of a voltage drop across a fully integrated sense resistor. The voltage drop is proportional to the inductor current in the pass device by supplying a fraction of the inductor current out of a source-follower, which matches to the pass device. The source of said source-follower is connected to a sense-resistor that is connected to the same supply as the pass device. The current, which is needed to generate the voltage drop, is fed back into the inductor current minimizing therefore the efficiency loss. Mirroring, amplification and offset correction of the voltage drop across the sense-resistor is performed by using a single matching pair of source-follower, which is supplied by a current tracking the internal reference voltage and the process variations of the resistors.

A semiconductor integrated circuit device includes a logic circuit, a digital-to-analog converter generating a substrate bias for controlling a threshold voltage of an MIS transistor of the logic circuit, a voltage control circuit outputting a control signal in accordance with a delay signal, and a delay detector, including a circuit which monitors variations in operating speed of the delay detector. The delay detector receives the clock signal and outputs the delay signal. The voltage control circuit receives the delay signal and outputs the control signal according to a delay indicated by the delay signal. The digital-to-analog converter receives the control signal from the voltage control circuit and generates a voltage according to the control signal. The operating speed of each of the logic circuits and the delay detector is controlled by a voltage supplied from the digital-to-analog converter.

This invention provides the two types of Discretely Controlled Micromirror (DCM), which can overcome disadvantages of the conventional electrostatic micromirrors. The first type micromirror is a Variable Supporter Discretely Controlled Micromirror (VSDCM), which has a larger displacement range than the conventional electrostatic micromirror. The displacement accuracy of the VSDCM is better than that of the conventional electrostatic micromirror and the low driving voltage is compatible with IC components. The second type of DCM, the Segmented Electrode Discretely Controlled Micromirror (SEDCM) has same disadvantages with the conventional electrostatic micromirror. But the SEDCM is compatible with known microelectronics technologies.

A digital frequency synthesizer provides absolute phase lock and shorter settling time through the use of a digital filter with a phase and frequency path. Control logic control disables the frequency path during the frequency acquisition and sets a wide bandwidth. After frequency acquisition, a counter with digital phase information is reset using the input clock signal to bring the output phase closer to lock with the input signal and the control logic enables the phase path in the digital loop filter to achieve phase lock with a narrower bandwidth than the initial bandwidth.

A voltage controlled oscillator with anti supply voltage variation and/or process variation includes an oscillation circuit for outputting an oscillatory signal; a current source coupled to the oscillation circuit for providing an input current to the oscillation circuit; and a variation compensation circuit for compensating the variations generated by the supply voltage and process. The variation compensation circuit includes a peak detector for generating a peak voltage proportional to the amplitude of the oscillatory signal; a compensating voltage generator for generating a reference voltage according to the process variation so that the oscillation circuit achieves the same working conditions under the process variation; and a comparator for comparing the peak voltage and the reference voltage to generate a control voltage. When the variation compensation circuit includes an amplifier, the supply voltage can be compensated.

The driver includes a digital-to-analog converter receiving a pixel value and outputting one of gamma voltages corresponding to the pixel value, and an output stage providing a driving voltage and a driving current corresponding to the gamma voltage outputted from the digital-to-analog converter, in which the driving voltage is provided during a first part of the programming period and the driving current is provided during a second part of the programming period.

The invention relates to a system for testing heat transfer and resistance characteristics of a large-size generating equipment heat exchanger. The system comprises a straight flow type air duct system, a circulating water system and a circulating oil system. The straight flow type air duct system inhales air, after heating, flow mixing and rectification, the air flows into the air cooling device; after heat exchange through an air cooling device tester, hot water is inputted by a water pump to a cooling tower for cooling, the cooled water is heated by an air heater to realize water temperature required by a test and then flows into a heat exchanger tester to form a temperature-controllable circulating water system; oil in an oil tank is heated, the heated oil flows into the heat exchanger tester, the oil after heat exchange flows into an oil storage tank to form the circulating oil system; the circulating water system and the circulating oil system respectively realize closed circulating and are used for testing heat transfer coefficients and resistance characteristics of the heat exchanger. The test system can test heat transfer and flow resistance characteristics of the air cooling device and an oil cooling device, can realize water cycle utilization and greatly saves resources.

A data slicer circuit for extracting data from a received analogue signal having a preamble and a data portion with the data. The circuit comprises a low pass filter for obtaining a DC value of the received signal, and a comparator for comparing the received analogue signal to the DC value of the received signal. In dependence on the comparison of the received analogue signal to the DC value of the received signal, the comparator generates a digital bit stream. A filter for rejecting the preamble frequency receives analogue signal and feeds a filtered signal to the low pass filter. By rejecting the preamble frequency, before or after, the low pass filter a shorter settling time can be obtained.

A dynamic frequency compensated operational amplifier having multiple gain settings includes a first differential to single ended amplifier stage; a second amplifier stage responsive to the first stage; a plurality of compensating capacitors; a multi-gain setting circuit for selectively setting the gain of the operational amplifier; and a control circuit, responsive to the gain set by the multi-gain setting circuit for connecting at least one of the compensating capacitors between the output and the input of the second amplifier stage for adjusting the frequency response of the operational amplifier.

The invention discloses an automatic gain control circuit for closed-loop drive of an MEMS gyroscope. The automatic gain control circuit comprises an amplitude comparator, a residual selector and a loop filter. The amplitude comparator automatically determines whether a gyroscope is in an oscillation starting phase or a stabilizing phase based on the magnitude of an output signal of the amplitude detector, and outputs a control signal for controlling an operation mode of the loop filter and the residual selector according to the determination result. The residual selector outputs an input signal required for the loop filter according to the control signal output from the amplitude comparator and a preset digital reference value. The loop filter generates a drive amplitude signal based on the input signal and the control signal output from the amplitude comparator. The invention designs the amplitude comparator in the automatic gain control circuit to realize the self-detection of a drive system and to adaptively adjust the operation mode of an automatic gain controller; and the oscillation starting time can be less at very small loop bandwidth, the stabilizing time is shorter, meanwhile, fewer design parameters are needed, and the system is more concise.

The comparison device includes a first through second comparators, a chop switching unit, a delta-sigma modulation unit, and a first through second compensation units. The chop switching unit transmits a first and a second signals to two input terminals of the first comparator during a first period, and inverses the first and second signals during a second period. The delta-sigma modulation unit compares the comparison results of two parallel comparators and generates the digital control codes for the comparators with the awareness of the chop switching unit. The first and the second compensation units adjust the threshold voltages of the comparators according to the digital control codes and a step size for calibrating the offset voltages of two comparators. The calibration scheme requiring no assumption on the input signal statistics is background thus the comparison device will not interrupt normal operation and is immune to PVT variations.

The invention relates to an improved self-correcting variable parameter fan coil temperature control method and special equipment. The special equipment comprises a coil fan loop, a coil water valve loop, a control panel and a controller, wherein the control panel is internally provided with a temperature setting circuit and a display circuit, the input/output ports of the temperature setting circuit and the display circuit are connected with the I/O ports of the controller directly or by virtue of an RS485 communication interface, the coil fan loop is provided with a direct current brushless fan and a return air temperature sensor, the control input terminal of the direct current brushless fan is connected with one control output terminal of the controller through a serial interface, and the signal output terminal of the return air temperature sensor is connected with one signal input terminal of the controller; and the coil water valve loop is provided with an electric two-way valve, and the control input terminal of the electric two-way valve is connected with two output terminals of the controller. The temperature control equipment disclosed by the invention improves accuracy on fan coil control, has good stability, realizes intelligent regulation management on a fan coil and saves energy.

The invention discloses a dynamic equation-based hypersonic-aircraft coupling analysis method. The method comprises the following steps: (1) establishing hypersonic-aircraft attitude dynamic-equations; (2) providing the dynamic equation-based hypersonic-aircraft coupling analysis method for flight characteristics of a hypersonic vehicle; (3) applying the dynamic equation-based hypersonic-aircraftcoupling analysis method, which is given in the step (2), to the hypersonic-aircraft attitude dynamic-equations, which are established in the step (1), to obtain dynamic coupling relationships betweenstatus and input; and (4) using the dynamic coupling relationships, which are between the status and the input and in an attitude model obtained in the step (3), to design a hypersonic-aircraft attitude coordination controller. The method starts from the system dynamic-equations, an obtained coupling relationship matrix is nonlinear and dynamic, and coupling situations under actual flight statusare more comprehensively and objectively reflected.

The invention provides a vector arc stage switching method and device for double rotary balance mass-based dynamic magnetic steel type magnetic levitation workpiece stages, and belongs to a semiconductor manufacturing equipment technology. The device comprises a support frame, a balance mass block, a rotating shaft, magnetic levitation workpiece stages, a workpiece stage measurement device and a workpiece stage drive device, wherein the two workpiece stages work between a measurement station and an exposure station; the positions of the workpiece stages are measured by plane gratings; the workpiece stages are driven by magnetic levitation planar motors; and the two workpiece stages are driven by the planar motors to achieve single-beat arc fast stage switching in the double workpiece stage switching process. According to the vector arc stage switching method and device, the problems that an existing stage switching scheme has multiple beats, a long track, multiple starting and stopping beats, long stabilization time and the like are solved; the stage switching link is reduced; the stage switching time is shortened; and the productivity of a lithography machine is improved.

The invention discloses a portable cholesterol molecular imprinting silk-screen printing electrochemical tester and belongs to the technical field of rapid detection. A silk-screen printing electrode is polymerized with template molecule cholesterol by electroplating and a mixed solution of a purified sample and conductive liquid is dropwise added on the surface of a working electrode of the silk-screen printing electrode; current of cholesterol can be directly read by the portable cholesterol molecular imprinting silk-screen printing electrochemical tester; a standard curve is corrected according to a silk-screen printing electrode piece with the cholesterol with the standard concentration; and the concentration of the cholesterol in the detected sample is calculated by a built-in program. The tester disclosed by the invention has a simple structure, is portable, sensitive, rapid and accurate, has high specificity and is economical. The tester can be used for directly detecting the cholesterol, has the advantages of portability, sensitivity, rapidness, high specificity and the like, has low price and is suitable for detecting the cholesterol on a base layer or in the field.

The invention relates to a method for rapidly obtaining constant gas humidity, which belongs to the gas humidity generation field. The method solves the problems of narrow obtained humidity generation scope and complex operation in the current constant humidity obtaining methods. The method is characterized in that an electric heater and a refrigerator are used for real time control of water-bath temperature in a constant temperature water-bath box, water-bath temperature in the constant temperature water-bath box is constant; after the water-bath temperature in the constant temperature water-bath box is constant, a pressure controller is used for drying nitrogen and pressing into No1-No3 mass flow controllers, drying nitrogen through the No1-No2 mass flow controllers pass through a saturator and then is introduced in a mixing chamber, the drying nitrogen through the No3 mass flow controller is introduced in a mixing chamber through a No1 heat exchange tube, constant humidity gas is output from the mixing chamber, so that constant gas humidity can be obtained. The method is used for obtaining the constant gas humidity.

An antenna diversity method and a corresponding communication device are disclosed that may be used in wireless LAN receivers. An AGC (Automatic Gain Control) unit controls a gain when processing signals received from antennae. A periodical switching process is performed between at least two antennae. During this periodical switching process, signals from each of the antennae are received alternately. The gain obtained by processing each received signal by means of the AGC unit is monitored and the obtained gain is compared with a predetermined threshold value. When for one of the at least two antennae the gain is below the predetermined threshold value, the periodical switching process is stopped and the antenna used at the time when stopping the periodical switching process is selected. This technique may provide an improved antenna diversity of low complexity, high performance and a short settling time.

The invention discloses a coordination control method for a hypersonic flight vehicle based on dynamic coupling analysis. The method includes the following steps: establishing a longitudinal system model of the hypersonic flight vehicle; bringing forward a dynamic coupling analysis method of the hypersonic flight vehicle for flight characteristics of the hypersonic flight vehicle; applying the dynamic coupling analysis method of the hypersonic flight vehicle to the longitudinal system model of the hypersonic flight vehicle to obtain a dynamic coupling relationship matrix between a trajectory variable, an attitude variable and a control input variable; and designing a longitudinal system coordination controller of the hypersonic flight vehicle. The method starts from a system dynamic equation, and the obtained coupling relationship matrix is nonlinear and dynamic, which reflects a coupling situation more comprehensively and objectively under an actual flight condition.