394results about How to "Small temperature drift" patented technology

A voltage reference source with high-order temperature compensation circuit belongs to the electronic technical field. The voltage reference source comprises a starting current and positive temperature coefficient current generating circuit, a negative temperature coefficient current generating circuit, a high-order temperature compensation current generating circuit and a superimposition and summation output circuit. The added high-order temperature compensation current generating circuit performs linearization to the breakover voltage VBE between the voltage of the base and emitter of a triode to obtain a high-order compensation amount which is in agreement with the high-order temperature amount of the PN junction voltage, and the high-order temperature coefficient of the PN junction voltage can be eliminated fundamentally after proportional offset, thus realizing a CMOS voltage reference source with the lower temperature coefficient. The voltage reference source is prepared by the common CMOS technology with lower cost, has extremely low temperature coefficient, less power consumption and smaller area, and can be used in the reference circuits such as analog circuits and digital-analog hybrid circuits which are required to have low temperature coefficients.

The invention provides a method for automatically correcting temperature drift of an electrical vortex sensor. According to the method, a certain impedance measuring circuit is utilized to obtain the equivalent inductance and the resistance of a detection coil, the relationship, changing along with temperature and measurement, of the inductance and the resistance of the detection coil is utilized to remove the influence of temperature changes and extract actual measured change information. According to the method, signals of the vortex sensor composed of an impedance measuring module (4) and a rectification calculating module (5) is used for conditioning the circuit, so that to-be-measured information is obtained, rectification is conducted automatically, and the influence of temperature changes is removed at the same time. According to the method, when temperature drift is rectified, no extra probes or coils or temperature sensors are further arranged, and temperature drift rectification effect is remarkable. Moreover, the method has the advantages of being wide in application range, simple in structure, easy to implement and the like. When the method is used for automatically rectifying the temperature drift of a probe of the electrical vortex sensor, temperature drift coefficients can generally be reduced to below 5nm / DEG C from 500nm / DEG C.

A capacitive pressure sensor of substantially ceramic material comprises a thick base plate (100), a front plate (140) having the same thickness as the base plate and a movable diaphragm (120) located between the front plate and the base plate. Capacitor electrodes (121b, 121a) are provided at the surface of the diaphragm facing the base plate and form a measurement capacitor. The diaphragm (120) is extremely thin and is produced by sintering a ceramic material such aluminium oxide. Owing to a pressing process used during the sintering a strong, very thin diaphragm is obtained having no mechanical stresses and fracture indications. It can be produced to have a very small thickness in order to provide pressure sensors having a high sensitivity, which can also for high-vacuum applications tolerate to be subjected to the atmospheric pressure. A shielding plate (110) can be inserted between the base plate (100) compensating the measurement capacitor. The shielding plate (110) can also be extremely thin, having a thickness down to a thickness corresponding to the thickness of a diaphragm (120).

A process for producing a plate for a capacitive sensor element. In one embodiment of the present invention, a method includes forming a plate from a substantially pure aluminum oxide slurry, heating the plate a first time in an oven to sinter the plate, cooling the plate after the heating step, heating the plate a second time to smooth the plate, and cooling the plate after the second heating.

The invention relates to a monolithic phase-locked surface-emitting distributed feedback semiconductor laser array, in particular to a new semiconductor laser array phase-locked structure solving the problems of monolithic incapability and difficult mounting and debugging of a traditional external coupling (Talbot outer cavity) phase-locked technology and the problem of a traditional internal coupling (leakage wave coupling) phase-locked technology that the light extraction efficiency is influenced by the limited width of a light extraction area. The structure comprises distribution Bragg reflectors and surface-emitting distribution feedback semiconductor laser array strips which are periodically and alternately arranged, an outer cavity feedback laser is formed by each surface-emitting distribution feedback semiconductor laser array strip and distribution Bragg reflectors at the left end and the right end, the distribution Bragg reflector at the left end provides the optical feedback of the outer cavity for the outer cavity feedback laser, the distribution Bragg reflector at the right end provides end surface reflection, and another outer cavity feedback laser is formed by the distribution Bragg reflector at the right end and the next laser array strip. The invention can be applied to the fields of military affairs, industries, medical treatment, space optical communication, and the like.

The invention discloses a high-speed narrow pulse modulation driving power supply for a semiconductor laser. The high-speed narrow pulse modulation driving power supply comprises a semiconductor laser driving circuit and a high-precision temperature control circuit, wherein the semiconductor laser driving circuit adopts a high-speed MOSFET as a switch. The driven semiconductor laser can output the required laser pulse with high frequency, quick advancing front, narrow pulse width, controllable pulse peak and smooth waveform according to the parameters of the semiconductor laser by changing the power supply voltage, resistance and capacitance in the driving power supply circuit.

The invention relates to a whirling vibration excitation and dynamic measurement device mainly comprising a signal source part, a vibration signal excitation part, a vibration signal dynamic collection and transmission part, and a power drive part of a whirling mechanism. For realizing vibration excitation and signal detection of the whirling mechanism (such as a round rod and a pipe), vibration excitation with different waveforms and excitation intensities is exerted on the whirling mechanism at different rotation speeds by utilizing matching connection and coaxial rotation of a vibration exciter and the whirling mechanism, and a wired or wireless transmission mode is adopted to realize signal collection and transmission of a multichannel vibration acceleration signal to be convenient for subsequent signal analyzing and processing. The whirling vibration excitation and dynamic measurement device can work under the condition that the whirling mechanism stalls or rotates to be convenient for being in connection with a signal generator or a signal generating device designed by a user to realize the vibration excitation and detection of a complex signal, can be used for theoretical characteristics and experimental study of mechanical vibration signal measurement, vibration characteristic analysis, low-frequency acoustic data transmission and the like and is simple in structure and convenient to operate.

The invention belongs to a network test technology, and particularly relates to an integrated network parameter tester and an integrated network parameter test method applied to a pulse regime. The tester comprises a built-in pulse generator module and a pulse modulation module connected with the pulse generator module. An excitation signal source module is connected with the pulse modulation module. The pulse modulation module is connected with a pulse high-power S parameter test module. The pulse high-power S parameter test module and a local oscillator signal source module are connected with a mixing receiver module respectively. The mixing receiver module is connected with an intermediate frequency processing module. The intermediate frequency processing module is connected with an embedded computer module through a digital signal processing module. By the tester and the test method, the shortcomings of large volume and high construction cost of the conventional test instrument are overcome; and network parameters can be flexibly and conveniently tested.

The invention discloses an intelligent pressure transmitter, which is provided with a digital temperature sensor and a pressure sensor. Temperature signals and pressure data can be acquired in real time, the pressure data are converted by an A / D (analog / digital) conversion module and then transmitted to a microcontroller for processing together with the temperature signals, so that temperature compensation, zero drift compensation and nonlinear rectification are realized for the pressure sensor. The intelligent pressure transmitter can overcome the shortcoming of zero drift of a traditional pressure transmitter, and has an excellent zero drift compensation characteristic and a fine time drift suppression characteristic.

The invention provides a pressure sensor micro-nano structure with the high stability under a high-temperature environment. The pressure sensor micro-nano structure comprises a silicon carbide membrane sheet, a reflection membrane, a semi-reflection membrane, a bonding layer, a silicon carbide substrate, a packaging layer and a sapphire optical fiber, wherein the reflection membrane is plated in the middle of the silicon carbide membrane sheet; the semi-reflection membrane is plated at the tail end of the sapphire optical fiber; the bonding layer is located between the silicon carbide membrane sheet and the silicon carbide substrate; and the sapphire optical fiber is connected with the silicon carbide substrate through the packaging layer, and is used for transmitting an optical signal. The detection device disclosed by the invention is simple in structure and strong in anti-interference performance, and pressure detection under the high-temperature environment can be realized.

The invention provides a low non-linear error and low temperature drift two-frequency laser interference device, comprising a first polarization splitting prism, a second polarization splitting prism located on a light path of transmitted light of the first polarization splitting prism; a third polarization splitting prism located on a light path of transmitted light of the first polarization splitting prism; a first quarter-wave plate, the second polarization splitting prism located between the first quarter-wave plate and the first polarization splitting prism; at least a first prism of corner cube deposited in parallel to one side of the second polarization splitting prism; a second quarter-wave plate located one end of the third polarization splitting prism. The invention uses a plurality of polarization splitting prisms cascaded and path length in the interference device of measuring light path and reference light path. Therefore the device has low non-linear error and low temperature drift.

The invention belongs to the technical field of optic fiber gyroscopes, and in particular relates to a preparation method of a sensing ring capable of reducing optic fiber gyroscope temperature drift. The method of the present invention adopts a quadrupole symmetry method and an octupole symmetry method to wind the optical fiber ring. With the method of the present invention, the shupe phase error due to the temperature is inhibited, and the temperature performance of the gyroscope is improved.

The invention provides a high-frequency surface acoustic wave resonator and a preparation method thereof. The high-frequency surface acoustic wave resonator comprises a high-wave-velocity supporting substrate, a piezoelectric film located on the upper surface of the high-wave-velocity supporting substrate and a top electrode located on the upper surface of the piezoelectric film, wherein the wavevelocity of bulk waves propagated in the high-wave-velocity support substrate is greater than the wave velocity of target elastic waves propagated in the piezoelectric film. According to the high-frequency surface acoustic wave resonator and the preparation method thereof provided by the invention, the problem that the working frequency of an existing surface acoustic wave resonator is relativelylow is solved.

The invention discloses a rotating transformer exciting circuit based on sinusoidal pulse width modulation (SPWM), which comprises a microprocessor, an analog demodulation circuit and a power amplification circuit, wherein the microprocessor adopts DSP to perform digital modulation so as to load a required sinusoidal fundamental wave signal to a high-frequency square wave carrier signal to form an SPWM wave signal, and output SPWM waves to the analog demodulation circuit in a differential mode. The analog demodulation circuit adopts a two-circuit duplicate-supply operational amplifier TL082, and one path of the operational amplifier forms a differential proportion calculator, while the other path forms a filter. The power amplification circuit adopts a two-circuit duplicate-supply linear power amplifier PA60 and a resistor to form a two-circuit reversed phase proportioner, and blocks the input sinusoidal fundamental wave signal and amplifies the power to generate an exciting signal and simultaneously drive a two-circuit rotating transformer to work. The rotating transformer exciting circuit has the advantages of simple circuit, safety and reliability, small temperature drift and direct current component, good stability of output signals, and low degree of distortion of output waveforms.

This invention discloses a CMOS craft compatible relative humidity sensor which is used in examining the humidity, by the substrate, taught and influenced the level, under the electric capacity the pole plate, on the electric capacity the pole plate is composed, teaches and influences the level to be located in on the substrate, under the electric capacity the pole plate even shop in taught and influenced on the level, on the electric capacity the pole plate was located thesubstrate and the oxide layer place above: The advantages are simple structure, the temperature drift slightly, strong anti-interference low cost, quickly response and easy detection.

The invention provides a digital geological compass and a method for measuring geological occurrence, an azimuth angle and inclination angle data acquisition module, a laser module, a power supply circuit and a display module respectively connected to a storage and control module are provided in a casing; the azimuth angle and inclination angle data acquisition module comprises a magnetic sensor, an acceleration sensor and an A / D converter; the storage and control module reads the azimuth angle and inclination angle data measured by the azimuth angle and inclination angle data acquisition module, a pitching angle and a roll angle are obtained, the azimuth angle, the pitching angle and the roll angle data are sent to the display module for displaying and storing when necessary. The digital geological compass and the method for measuring geological occurrence have the advantages of high precision, convenient operation and high efficiency, and have angle compensation function by using a three-dimensional (shaft) technology when the azimuth angle is read, the real-time reading under compass horizontal are not necessary, so that the operation time can be greatly reduced.

The invention discloses a solar array hinge torque tester which includes a motor, a support, a base and a reducer, and is characterized in that the base and the support with rack are vertically fixed and connected; a fixed tip is arranged on the base; the motor and the reducer are arranged in the base; the motor and the reducer are fixed and connected by a coupler; the fixed tip is fixed on the reducer; the support is provided with a movable tip movably connected with the rack; the reducer is provided with an angle sensor; the movable tip is provided with a torque sensor; the tested data is connected to a PC to be processed; the invention is integrated with movement, control and measurement, adopts a special heating structure of initiative temperature control, can work under -100 DEG C to +70 DEG C of wide temperature, solves the problems of poor adaptability and stability of the tester under vacuum, high-temperature and low-temperature environment, is very applicable in ground simulation test of hinge assembly components of all star and ship solar array unfolding mechanisms, and has the advantages of high test precision, good load matching performance, little temperature drift of the torque and angle sensors.

The invention discloses a method for conducting pressure calibration on diffused silicon sensors through an upper computer. The method is based on digital acquisition conducted on output of the diffused silicon sensors and based on temperature and pressure compensation conducted on acquired data. A device for conducting pressure calibration on the diffused silicon sensors comprises a microprocessor, a communication interface circuit, a sensor digitalization interface circuit and a data storage circuit. The method avoids the situation that the diffused silicon sensors are calibrated generally through adjustment of zero-point potentiometers and full-scale potentiometers in circuits in the calibration process of the diffused silicon sensors at present. The method overcomes the defects that precision drift of the diffused silicon sensors is caused by drift of the potentiometers in the circuits, the diffused silicon sensors cannot be calibrated in batches, and linear precision of the diffused silicon sensors cannot be adjusted. The method has the advantages that stability is good, the precision is high, temperature drift is little, and calibrating intellectualization is achieved.

The invention discloses a stable holder based on an MEMS gyroscope combination. The stable holder is composed of a class-A MEMS gyroscope sensor and a class-B gyroscope sensor. The class-A MEMS gyroscope sensor has high bandwidth and low noise. The class-B gyroscope sensor has low temperature drift and random drift. Multiple gyroscope sensors of different types are used to construct a combined sensor unit, and the advantages of different types of sensors are exerted through a reasonable control architecture and process. Therefore, the inertial measurement feedback and stability control performances are significantly improved, and the problem that the performance requirements are usually not satisfied in high-performance inertial attitude measurement and attitude stabilization is solved. The invention further discloses a control method of the stable holder based on an MEMS gyroscope combination.

The invention discloses a manufacturing method of a high-precision pressure sensor based on silicon-silicon bonding. The high-precision pressure sensor comprises a sensitive silicon wafer layer and a substrate silicon wafer layer and is characterized in that the substrate silicon wafer layer is connected to the back of the sensitive silicon wafer layer, and the sensitive silicon wafer layer and the substrate silicon wafer layer use silicon-silicon bonding process to form a pressure sealing cavity; the substrate silicon wafer layer and the sensitive silicon wafer layer are made of homogenous monocrystalline silicon materials, and the substrate silicon wafer layer is provided with a pressure guide through hole in the center. The manufacturing method has the advantages that the substrate silicon wafer layer and the sensitive silicon wafer layer are made by using the monocrystalline silicon materials as the substrates, the substrate silicon wafer layer and the sensitive silicon wafer layer are connected in an airtight manner through the silicon-silicon bonding process, the pressure sealing cavity of a silicon-silicon homogenous material structure is formed, various influences, caused by the pressure sealing cavity of the silicon-glass heterogeneous material structure of a conventional pressure sensor, on the performance of the sensor due to the feature difference of two different materials are avoided, static pressure errors are reduced effectively, temperature excursion of the sensor is lowered, and the comprehensive precision of the sensor is increased.

The invention discloses a conditioning circuit of a linear variable differential transformer (LVDT). The conditioning circuit comprises a half-bridge position sensor, an analog-digital conversion circuit, a controller data processing unit, an upper computer, a sine wave generating circuit, an inverting circuit, an amplifying circuit, a channel selector switch, an absolute value circuit and a peak holding circuit, wherein the analog-digital conversion circuit is connected with the upper computer through the controller data processing unit; one path of the output end of the sine wave generating circuit is connected with the positive input end of the position sensor through the inverting circuit, and the other path of the output end of the sine wave generating circuit is connected with the positive input end of the position sensor; the output end of the position sensor is connected with the input end of the channel selector switch through the amplifying circuit; the output end of the channel selector switch is connected with the input end of the peak holding circuit through the input end and the output end of the absolute value circuit; and the output end of the peak holding circuit is connected with the input end of the analog-digital conversion circuit. The conditioning circuit consisting of discrete components has the advantages of low temperature excursion and low cost.

The invention discloses a microelectromechanical z-axis detection structure with low thermal drifts. A MEMS detection structure is provided with: a substrate having a top surface, on which a first fixed-electrode arrangement is set; a sensing mass, extending in a plane and suspended above the substrate and above the first fixed-electrode arrangement at a separation distance; and connection elastic elements that support the sensing mass so that it is free to rotate out of the plane about an axis of rotation, modifying the separation distance, as a function of a quantity to be detected along an axis orthogonal to the plane. The MEMS detection structure also includes: a coupling mass, suspended above the substrate and connected to the sensing mass via the connection elastic elements; and an anchoring arrangement.

The invention relates to the paddy rice cultivation technical field, and especially relates to a rice field water volume automatic detection irrigation recording system; the system uses humiture and water level sensor technical means to measure the rice field water content and temperature, thus saving manpower, material resources, and time; the sensor can automatically detect all day, and provides accurate data; a one-chip microcomputer automatic control technical method can solve the technical problems, and can provide rice field automatic detection, automatic wireless transmission, and automatic water sucking and supplying technical effects; the GPRS wireless transmission technology can solve the technical problems of complex wiring and high cost when a controller is applied, thus realizing simple wireless transmission line and stable signal; water level sensing technical method is applied, so the rice field water level depth can be simply and directed detected.

The invention relates to a thickness and convexity detection device for plates and strips and belongs to the field of nuclear technology application. The device comprises a C-shaped frame, two ray sources which are arranged in an upper arm of the C-shaped frame along a width direction of a steel plate to be detected at an interval, two rows of high-pressure aeration ionization chamber detector arrays which are arranged in a lower arm of the C-shaped frame along a motion direction of a plate or a strip at intervals, a collimator which is arranged below the two ray sources and used for making each ray source emit a ray to the corresponding one row of detector array, a preamplifier connected with the detector arrays, a data acquirer connected with the preamplifier, a data processing and display computer connected with the data acquirer, a steam service system for guaranteeing running of a system and monitoring, and a control system. The thickness and convexity detection device is simple in mechanical structure and high in dynamic measurement precision; furthermore, the detector has the advantages of low temperature drift, high radiation resistance, high space resolution, high cost performance and the like.

The invention provides a high-frequency acoustic wave resonator and a preparation method thereof. The high-frequency acoustic wave resonator comprises a high-acoustic-velocity support substrate, an insulating dielectric layer which is located on the upper surface of the high-sound-velocity supporting substrate, a piezoelectric film which is located on the upper surface of the insulating dielectriclayer, and an interdigital electrode which is located on the upper surface of the piezoelectric film. By arranging the high-sound-velocity supporting substrate below the piezoelectric film, the soundvelocity of target elastic waves excited and propagated in the piezoelectric film can be increased, propagation of the target elastic waves can be effectively restrained, and the resonant frequency of the high-frequency sound wave resonator is improved; the insulating dielectric layer is arranged between the piezoelectric film and the high-sound-velocity supporting substrate, the leakage of electric field energy in the piezoelectric film can be effectively reduced, and the electromechanical coupling coefficient of the high-frequency sound wave resonator can be enhanced; by selecting the appropriate insulating dielectric layer, temperature compensation can be carried out on the high-frequency acoustic wave resonator, temperature drift of the high-frequency acoustic wave resonator is reduced, and temperature stability of the high-frequency acoustic wave resonator is improved.

The invention relates to a complementary metal-oxide-semiconductor (CMOS) integrated circuit, in particular to a high-accuracy resistance-capacitance (RC) oscillator. The RC oscillator provided by the invention adopts a two-stage regulation way, wherein first-stage regulation is the regulation of a comparison reference voltage, and aims to regulate the output frequency of the oscillator into the range of second-stage regulation; and the second-stage regulation is the regulation of charging current, and aims to make the accuracy of the output frequency of the oscillator meet designing requirements. The generation of the comparison reference voltage and the constant current source designing of the charging current are both based on a band gap reference source so as to achieve the advantage that the reference voltage and the charging current both have low temperature coefficients to endow the RC oscillator with the advantage of low temperature drift. The RC oscillator adopting the two-stage regulation design overcomes the shortcoming of the conventional structure that variations of integrated circuit process parameters may cause function failures, and simultaneously, the two-stage regulation is operable and convenient to actually operate.

The invention relates to an intelligent alarm rain gauge, which comprises a rain gauge, an alerter and a measuring cylinder, wherein the lower part of the measuring cylinder is provided with a water drain valve and a pressure sensor; the pressure sensor is connected with the alerter and is installed on a fixed seat, and the pressure sensor is connected with the alerter through a cable; and the alerter comprises a case, an LED (Light-Emitting Diode) display screen installed on the case, and a control circuit installed in the case. The intelligent alarm rain gauge has the advantages of simple structure, small size, no pollution, light weight, long service life and low standby power consumption and can not be polluted or corroded by dust, greasy dirt, moisture, salt mist and the like. The intelligent alarm rain gauge has the characteristics of simplicity in installation, convenience in maintenance and more humanized operation, and the intelligent alerter can be externally connected with a simple rain gauge or tipping-bucket rain gauge. A communication mode adopts standard RS485 communication. The intelligent alarm rain gauge also has the advantages of stable running, high reliability, high compatibility, high accuracy of measured values, small temperature drift and small influence from environmental factors.

A detection circuit for measuring micro differential capacitor comprises a frequency selection circuit, a phase-locked loop tracking circuit, a logic gating circuit and a low-pass filtering circuit, wherein the frequency selection circuit and the phase-locked loop tracking circuit are formed into resonance units; the resonance frequency of each resonance unit is determined by the capacity of a to-be-measured differential capacitor; and two sets of resonance units formed by the differential capacitor can realize frequency output in direct proportion to the capacity of the differential capacitor under the action of a back-end logic gating circuit and the low-pass filtering circuit. The detection circuit has high detection precision and output linearity, small temperature drift and strong anti-interference capacity; moreover, the detection circuit has simple circuit structure and is convenient for engineering and integrated circuit making. The detection circuit is suitable for the measurement based on micro differential capacitor sensitive mechanism in the fields of medical apparatus, security-monitoring detection, inertia device and fluid characteristics measurement.

The invention provides a silicon micro-resonant type accelerometer which mainly comprises a glass substrate. A silicon micro-mechanical structure is bonded to the surface of the glass substrate and comprises a mass block and four silicon micro-mechanical structure units, the mass block is of a central symmetry structure, and the mass block is surrounded by the four silicon micro-mechanical structure units which are arranged in a pairwise symmetry mode; each silicon micro-mechanical structure unit comprises a resonant type double-end tuning fork, a micro-mechanical lever and a decoupling guiding support, one ends of the decoupling guiding supports are connected with the mass block to receive inertia force, the other ends of the decoupling guiding supports are connected with one force input ends of the micro-mechanical levers, and the received inertia force is transmitted by one force output ends of the micro-mechanical levers to the resonant type double-end tuning forks.

The invention discloses a withstand high voltage eddy current displacement sensor comprising shell, skeleton winded with induction coil and short circuit ring with inner casing between them, inner shell is made of withstand high voltage nonpermeametion material and outer shell of soft magnetic material, induction coil winded by high strength wire is used to measure dynamic or static displacement. It has wide measuring range, good linearity, high mechanical strength and thermal stability, wide frequency response, extending limitation of traditional eddy current displacement sensor, so can be widely used in displacement measurement of valve core or hydraulic cylinder piston under high voltage.