109results about How to "Avoid temperature drift" patented technology

The invention discloses a digital dip-angle sensor, which comprises a dip-angle sensor chip, a signal conditioning amplification module, an A/D analog-to-digital conversion module, a signal processing module and a signal output module. The dip-angle sensor chip is integrated with a temperature sensor for sensing the temperature of a carrier. The invention has the advantages that the signal conditioning amplification module is arranged between the dip-angle sensor chip and the A/D analog-to-digital conversion module, the signal conditioning amplification module amplifies and filters an analog voltage signal output by the dip-angle sensor chip, then the processed analog voltage signal is transmitted to the A/D analog-to-digital conversion module and processed by the signal conditioning amplification module so that the resolution of the sensor is improved efficiently. On the other hand, the dip-angle sensor chip is integrated with the temperature sensor and outputs a digital temperature signal to the signal processing module for analysis and processing so as to provide temperature compensation for actual measurement, thereby efficiently solving the drift problem and improving the measurement precision.

The invention provides a high-gain and low-noise differential trans-impedance amplifier. The high-gain and low-noise differential trans-impedance amplifier comprises a current mirror, an adjusting type common-emitter and common-base trans-impedance amplifier and an output common-source amplifier, wherein the adjusting type common-emitter and common-base tarns-impedance amplifier comprises a common-base amplifying unit and a negative feedback common-emitter amplifying unit; the negative feedback common-emitter amplifying unit is arranged between an emitter and a base of the common-base amplifying unit and serves as a negative feedback channel; input current is copied by the current mirror in an equal proportion manner; the current mirror provides bias voltage for the common-base amplifying unit and the negative feedback common-emitter amplifying unit; the output common-source amplifier is connected between an output end of the adjusting type common-emitter and common-base trans-impedance amplifier and an output end of the high-gain and low-noise differential trans-impedance amplifier; and trans-impedance gain is increased. By the high-gain and low-noise differential tarns-impedance amplifier, received weak signals are amplified in a high-gain and low-noise manner, bandwidth is large, and a dynamic range of inputted current signals are reasonably set; and the high-gain and low-noise differential tarns-impedance amplifier has the advantages of easiness in design and monolithic integration.

The invention relates to a giant magnetoresistance current sensor and relates to a device for measuring currents. The giant magnetoresistance current sensor is composed of an electromagnetic conversion module, a signal amplification module and a feedback compensation module, wherein the electromagnetic conversion module comprises a magnetic core of a magnetism accumulation ring, a primary winding and a giant magnetoresistance chip, the signal amplification module comprises an operational amplifier and a push-pull power amplifier, and the feedback compensation module is a feedback winding. The whole measurement circuit forms a closed loop system, and the giant magnetoresistance chip and the magnetic core of the magnetism accumulation ring form a closed structure. The giant magnetoresistance current sensor overcomes the defects that a giant magnetoresistance current sensor in the prior art is very prone to interference of an external stray magnetic field, temperature drift and zero drift cannot be eliminated completely, and the measurement accuracy is affected by intrinsic magnetic hysteresis existing in a magnetic device.

The invention relates to a miniature electric field measuring apparatus, which comprises an electric field probe, a signal simulation conditioning circuit, a data acquisition and processing circuit adopting a mixed-signal processing chip, and a data storage and transmission circuit based on ARM. The inside of the electric field probe is provided with a moving plate and a driving device thereof and two groups of fixed plates; the two groups of fixed plates are directly etched on a printed circuit board; and the driving device of the moving plate is a common miniature direct current motor. The position of the moving plate of the electric field probe is detected by acquiring fluctuating signals generated in phase change of an electrode of the direct current motor. The outputs of the two groups of moving plates are taken as the input of the mixed-signal processing chip after being amplified by two paths of alternating current, the input is subjected to internal programmable gain amplification and then directly performs alternating current difference sampling, and the peak value and the polarity of the electric field are detected by software detection. An acquired electric field value is transmitted to an intelligent storage card for storage or to a terminal computer in a wired or wireless mode. The miniature electric field measuring apparatus has the advantages of simple structure, inhibition of temperature drift, strong electromagnetic interference resistance, and wide dynamic range and high precision in measurement.

The invention discloses a single-channel servo control module which comprises a double-layer data redundancy interface, a signal collecting detection interface, a servo driving interface, and a module main central processing unit (CPU). The data redundancy transmission interface forms a data transmission channel, and is connected with the module main central processing unit. The signal collecting detection interface collects the valve position and the handle operating panel information, and is connected with the main central processing unit. The servo driving interface drives the on-site electro-hydraulic servo valve, and is connected with the main central processing unit. The data redundancy transmission interface exchanges data with the main station DPU. A valve position given signal sent by the DPU and an LVDT feedback signal of the on-site oil motor are processed by a PID adjuster in the main central processing unit, the servo current is outputted to drive the electro-hydraulic servo valve, and then the valve-regulating travel of the turbine is controlled. The invention can reliably run in a long period under poor industry environments, and can monitor various working states in the clamping pieces through communication ports, and the interior software can be upgraded on line.

The invention discloses a high-temperature eddy-current displacement sensor temperature compensation method based on temperature online measurement and a sensing device. The high-temperature eddy-current displacement sensor temperature compensation method is characterized in that based on the input-output characteristics of a high-temperature eddy-current displacement sensor before temperature compensation, according to the environment temperature, measured by a temperature sensor, of the eddy-current displacement sensor, the sensitivity of the sensor within the whole linear working range is automatically adjusted through an automatic temperature-drifting-sensitivity correcting circuit in a front-arranged device, compensation is carried out on the sensitivity of the sensor at different temperatures, and therefore the influences of the environment temperature of the sensor on the sensitivity of the sensor are reduced; compensation is carried out on temperature drifting of the eddy-current displacement sensor at any reference point within the linear working range in the mode that the automatic temperature-drifting-sensitivity correcting circuit in the front-arranged device automatically outputs a voltage signal, and therefore the output of the eddy-current displacement sensor at the reference points can not be influenced by the environment temperature of the sensor.

The invention relates to a detection method and an in-situ detection device based on fluorescence intensity ratio of two detectors. The detection method comprises the following steps that: a light-exciting unit emits parallel light beams with certain wavelengths, and two photoelectric detectors positioned in the direction vertical to the parallel light beams and having an interval of d are used for detecting fluorescence signals; and based on the Lambert-Beer law, a proportional relation model between strength ratio of the two paths of fluorescence signals and the chlorophyll concentration in the water body is established. The detection device further comprises a signal processing unit, a window cleaning unit, a waterproof airtight cavity, an environmental protection cover unit and the like. With the adoption of the detection method and device, the influences caused by fluctuation of incident light, temperature variation, light scattering, pollution of a detection window and the like can be reduced, and the linear range of detection is expanded.

The invention discloses a method of temperature drift estimating and compensating in a scanning probe microscope, the method includes using the scanning probe microscope to obtain sample surface images at fixed sampling intervals, dividing each image into a plurality of pieces to carry out gradient processing, using a phase correlation method to calculate the drift distances of the images obtained at adjacent sampling times in the X and Y directions, using the density cluster density-based spatial clustering of applications with noise (DBSCAN) algorithm to reject noisy data and then calculating the whole drift distances of the images; then using the neural network method to speculate the drift distance at a next sampling time according to the previous drift distances and present near-field temperature data, and furthermore improving neural network parameters according to drift distance data obtained by actual measurement and calculation; and speculating obtained drift distance at the next sampling time and inputting the drift distance to a controller as a feed-forward signal, wherein compensation is made by the controller according to the feed-forward signal, so that the temperature drift is restrained, and automatic control is achieved. The temperature drift generated by the scanning probe microscope along with time in the environment without strict temperature and humidity control can be effectively restrained.

The invention discloses a digital phase-locked amplifier with multiple reference modes. The digital phase-locked amplifier comprises an analog link and digital module that are sequentially connected, wherein the digital module comprises a reference mode selector and multiple reference phase-locked loops that are connected with the reference mode selector in parallel; and a signal to be measured enters the analog link and is subjected to amplification, filtering and analog to digital conversion to form a digital signal to be measured, and the reference mode selector selects a corresponding reference mode to perform phase-locked amplification and complete the measurement of the phase and amplitude of the signal to be measured. The analog link comprises a low noise pre-amplifier, an anti-aliasing filter and an analog to digital converter that are sequentially connected; and the reference phase-locked loops comprise an external reference phase-locked loop, a cross-reference phase-locked loop and an external reference phase-locked loop. By adopting the digital phase-locked amplifier disclosed by the invention, the amplitude and phase can be simultaneously calculated, the overall structure is simple, and no analog circuit components need to be added.

The invention discloses an electrical insulation electric heating aging test device under composite voltage, which comprises two corona-free high-voltage test transformers and at least one test box, wherein a box body of the test box insulates heat; the test box is internally provided with a heating device; at least one high-voltage electrode which is connected with high-voltage output ends of the corona-free high-voltage test transformers is introduced to the top of the test box; the lower part of the test box is provided with at least one detection terminal; and the high-voltage electrodes and the detection terminals are respectively insulated with the box body of the test box. The electrical insulation electric heating aging test device under composite voltage provided by the invention can effectively simulate the composite electricity and heat stress borne by an electrical device in operation, also can test sample products under different temperatures, voltage types and voltage grades at the same time, and can obtain the breakdown voltage and breakdown time of the sample products in the aging process.

The invention discloses a telephoto lens, a telephoto camera module group and an electronic device. According to the embodiment of the invention, the telephoto lens sequentially comprises a first lenshaving a positive refractive power, a second lens having a negative refractive power, a third lens having a refractive power and a fourth lens having a refractive power from the object side to the image side. The object side surface of the first lens is a convex surface. The object side surface and the image side surface of the second lens are both concave surfaces. The object side surface of thethird lens is a concave surface. The telephoto lens satisfies the following relationship: TTL/f<0.96, wherein TTL is the distance from the object side of the first lens to the imaging plane of the telephoto lens on the optical axis, and f is the effective focal length of the telephoto lens. The telephoto lens has a short TTL through a reasonable TTL configuration, thereby shortening the cone length of the telephoto lens.

The invention is applicable to the technical field of diamond synthesis, and provides a seed crystal tray and base station assembly for diamond monocrystal homoepitaxy, and an application thereof. The seed crystal tray is placed on a water cooling stage of a microwave plasma chemical vapor deposition device, and a through hole for placing a seed crystal is formed in the center of the seed crystal tray. The base station assembly for diamond monocrystal homoepitaxy includes the water cooling stage and the seed crystal tray arranged on the water cooling stage, and the seed crystal tray is the seed crystal tray for diamond monocrystal homoepitaxy.

The invention discloses a power source device for a dental machine grid-control cold cathode X-ray tube, and belongs to the technical field of medical apparatuses and instruments. The power source device for the dental machine grid-control cold cathode X-ray tube is structurally composed of a high-voltage power source (1), a grid electrode power source (2), a single-chip microcomputer board (3), a grid-control bulb tube (4), current detection (5) and a closed-loop control panel (6). The power source device for the dental machine grid-control cold cathode X-ray tube is technically characterized in that the power source device does not need to be heated through filaments, the grid electrode power source is used for controlling the dental machine grid-control cold cathode X-ray tube to be opened and be closed, and the grid electrode power source controls tube current and forms closed-hoop control with the tube current. The power source device for the dental machine grid-control cold cathode X-ray tube has the advantages that a grid electrode switch ensures steepness of a leading edge and a lagging edge of a high-voltage wave form, the grid electrode power source and the tube current from closed-loop control to carry out dynamic adjustment on grid electrode voltage and the tube current, and current stability of the dental machine grid-control cold cathode X-ray tube is improved.

The invention provides a high-resolution time interval measuring device with a temperature compensation function and aims to solve the problem that time interval measuring accuracy is affected by small errors caused by a constant-current source circuit. A first resistor and a second resistor are added at an output end of an operational amplifier in the constant-current source circuit, and resistance value of the second resistor is 1/N of that of an equivalent resistor of a first NPN triode. Equivalent noise current output by the operational amplifier is at a fixed value, so that noise equivalent current entering a base electrode of the first NPN triode is reduced to be 1/(N+1) of an original value through current dividing of the resistance value of the second resistor, the high-resolution time interval measuring device has the characteristic of low noise, and measuring accuracy is improved.

The utility model relates to a pipe-type full-spectrum water quality detection device, and the device comprises a spectrograph for full-spectrum acquisition, and further comprises an optical fiber-based reflective probe arranged on a pipe, a xenon lamp light source which is used for providing ultraviolet light and visible light, a cooperative work module which is used for synchronizing the light source, the spectrograph and a waterway, a controllable waterway pipe which is used for waterway control and cleaning, a constant-temperature box which is used for placing the spectrograph and the xenon lamp light source, and a data processing and display module which is used for spectral data processing and water quality index display. The invention further provides a pipe-type full-spectrum waterquality detection method. Various water quality parameters can be measured at the same time; the pipe-type installation based on an industrial field facilitates the maintenance, is strong in self-cleaning capacity, enables the probe not to be prone to pollution, and enables the spectrograph, the light source and other electronic equipment to be placed in a constant-temperature box to achieve reliable operation at the temperature of-20 DEG C to 60 DEG C; a PCA dimension reduction and BP neural network learning method is used to realize rapid and reliable measurement of a plurality of mixed substances in full spectrum data.

The invention discloses a fission chamber output signal digital processing system and a method thereof, relates to the technical field of nuclear reactor. The system contains a preamplifier circuit and a digital processing device, wherein the digital processing device contains a signal processing unit, a high-speed analog signal acquisition unit and a signal output unit. The high-speed analog signal acquisition unit is respectively connected with the preamplifier circuit and the signal processing unit and is used for acquiring an output signal of the preamplifier circuit and converting the output signal into a digital signal for outputting. The signal processing unit is connected with the high-speed analog signal acquisition unit and is used for determining the root-mean-square value of the digital signal acquiring neutron flux according to the root-mean-square value and a calibration coefficient of preset neutron flux measuring range. According to the invention, circuit is simplified, problems such as temperature drift of components and noise in the analogue processing circuit are avoided, precision of the measurement result is raised, and stability of the system is increased.

The invention relates to a two-dimensional magnetic field sensor. The two-dimensional magnetic field sensor comprises a magnetic flux guiding device, wherein the magnetic flux guiding device is arranged on a substrate, an external frame of the magnetic flux guiding device is an annular or semi-annular structure, and according to a symmetric axis, the magnetic flux guiding device is divided into two or four areas; each area is provided with a magnetoresistor placement gap; each area is provided with a pair of magnetoresistors, the magnetoresistors are all arranged on the substrate, the magneticflux guiding device covers one magnetoresistor, and the other magnetoresistor is arranged in the corresponding magnetoresistor placement gap; and two pairs of magnetoresistors on two diagonal areas are connected into two sets of wheatstone bridge structures respectively. The two-dimensional magnetic field sensor has the advantages that the two-dimensional magnetic field sensor adopts single-coreintegration, and the integration level is high; the magnetoresistors in magnetic flux guiding device gaps and the magnetoresistors covered by the magnetic flux guiding device are utilized to compose two sets of wheatstone bridge structures to form differential output; compared with a former two-dimensional magnetic field sensor, the precision is higher, the antijamming capability is strong, the miniaturization and integration are easier, and double bridges can effectively inhibit temperature drift.

A single-chip full-bridge TMR magnetic field sensor comprises magneto-resistor elements and a bias current branch, and the magneto-resistor elements are in bridge connection to form a full-bridge structure; each magneto-resistor element comprises a free layer, a pinning layer and a bias current layer, the bias current layer is connected with the bias current branch, and the bias current branch inputs a bias current to the bias current layer; and directions of the currents in the bias current layers in the magneto-resistor elements located on adjacent bridge arms are opposite, and the directions of the currents in the bias current layers in the magneto-resistor elements located on the opposite bridge arms are the same. In the invention, the bias current layer is arranged in each magneto-resistor element; the bias current layer is used for changing a magnetization direction of the free layer in each magneto-resistor element, and sensitivity to an external magnetic field is achieved; anda magnetic field sensor can form the full-bridge structure on a single chip at a time, and difficulty and production cost of a single-chip full-bridge magnetic sensor manufacturing process are greatlyreduced.

The invention discloses a device for monitoring out-of-control falling of lifting equipment. The device comprises an acceleration sensor, a low-pass filter, a high-pass filter, a first comparator, an integrator, a second comparator and a latching relay, wherein an output terminal of the acceleration sensor is connected with an input terminal of the low-pass filter; an output terminal of the low-pass filter is connected with an input terminal of the high-pass filter; one path of output of the high-pass filter is connected with the integrator through the first comparator; another path of output of the high-pass filter is directly connected with the integrator; an output terminal of the integrator is connected with an input terminal of the second comparator; an output terminal of the second comparator is connected with an input terminal of the latching relay; and an integrator switch is connected in series between the first comparator and the integrator. According to the device disclosed by the invention, a complex mechanical principle is replaced by using an acceleration principle, and thus the out-off-control falling monitoring of the lifting equipment such as elevators is realized. The device has the advantages of simple structure, small size, low cost, easiness in mounting and the like and has universality and practicality.

The invention discloses a microcurrent detecting system in dielectric medium insulation diagnosis. The system comprises an I-V conversion amplifying circuit, a temperature drift inhibiting circuit, an instrument amplifying circuit and a power source filter circuit, and a grounded metal shielding box is arranged for the circuit. The microcurrent detecting system is characterized in that microcurrent is converted into voltage through the I-V conversion amplifying circuit and subjected to primary amplifying, the microcurrent is further amplified through the instrument amplifying circuit and output, the temperature drift inhibiting circuit offsets temperature drift of an operational amplifier in the I-V conversion circuit, the detecting precision is improved, the influence of power source fluctuation and harmonic waves on the detecting precision can be reduced through the power source filter circuit, and the influence of the external electromagnetic environment can be reduced through the grounded metal shielding box. The I-V conversion amplifying circuit comprises a T type feedback circuit and a range changing switching circuit, and therefore input impedance is increased, and the detecting range is widened. According to the module, the microcurrent detecting precision is high, and the detecting range is wide. The system has high application value.

The invention provides an orthogonal planar mobile robot pose detection device and method. The device comprises an overall fixed block, a supporting frame, and four driven wheel sets. The overall fixed block is arranged on the supporting frame; each driven wheel set comprises a driven wheel support, an omnibearing driven wheel, a connecting mechanism, a sliding mechanism and a linear speed acquisition module, and the driven wheel sets can rotate around the wheel shaft of the driven wheel sets, can slide in the vertical direction perpendicular to the shaft of the omnibearing driven wheels and are kept in contact with the ground all the time, and the position and posture of a mobile robot can be calculated without referring to the position of an object or other known reference information.