38results about How to "Good resistance to electromagnetic interference" patented technology

A current measuring method includes utilizing current magnetic field sensing probe formed by piezoelectric ceramic and amorphous alloy to convert current linear magnetic field to be voltage analog signal and sending it to electrooptical converting element where converts electrooptical analog signal to be analog light signal and sends it to earth potential side, converting said light signal to be analog electric signal and converting this electric signal to be digital signal by A / D converter for outputting. The electrical current mutual inductor of the method is also disclosed.

A nano-type magnetosensitive rotation speed sensor is composed of sensing unit and post-processing circuit. Said sensing unit consists of magnetic head, Fe-base nano magnetic band wound by coil L, adjustable bias magnet and casing. Said post-processing circuit comprises voltage stabilizer, magnetosensitive oscillator, filter amplifier, shaper and OC gate. Its advantages are high sensitivity, long active distance, high thermal stability and anti-interference power, and long service life.

The invention relates to a method for detecting the freshness of a mango by using an acoustic surface wave (ASW) detector. The method comprises the following steps of: (1) standing a weighed mango to be detected between two energy converters of the ASW detector in a transverse manner and a longitudinal manner respectively, enabling the distance from one end, nearest to the mango to be detected, of the two energy converters to the mango to be detected to be 1-5 mm, and starting up the ASW detector and carrying out detection for 30-60 s; and (2) gathering data acquired by the energy converters to obtain the ASW frequency data F of the mango sample to be detected, according to a preset first-grade freshness critical value F5 and a preset second-grade freshness critical value F7, judging the mango sample to be detected to have first-grade freshness if F is less than F5, judging the mango sample to be detected to have second-grade freshness if F is no less than F5 but is less than F7, judging the mango sample to be detected to be stale if F is no less than F7, and obtaining the grade of freshness of the mango to be detected. The method for detecting the freshness of the mango by using the ASW detector has the advantages of fast detection speed and good reliability in detected results.

The invention relates to the sensor measuring field, and discloses a tire-pavement three-dimensional force measuring device comprising a base plate, a contact plate arranged on the base plate, and a sensor array arranged on the base plate; the sensor array comprises an array support having a plurality of fiber grating sensor groups; each fiber grating sensor group comprises n fiber grating sensors vertically arranged in parallel; the sensor array also comprises a fiber grating demodulator; the fiber grating sensors are respectively connected with the fiber grating demodulator; the fiber grating sensors respectively penetrate through holes arranged on the contact plate and extend outside the top surface of the contact plate. The invention also discloses a tire-pavement three-dimensional force measuring method. More sensors are arranged on per unit area, thus improving the measuring precision, improving the anti-electromagnetic interference performance, and greatly reducing the channel number; the measuring device is simpler in structure, thus saving cost.

The invention discloses a signal processing method and a measuring device for a high-voltage frequency converter. A voltage collecting circuit adopts a resistance division processing mode and is characterized in that voltage signals of input and output ends of a high-voltage frequency converter are collected respectively in the resistance division mode; the collected voltage signals are sent into an input/output voltage detecting device, are subjected to differential amplification, isolation and filtering of a modulation circuit, and then subjected to signal modulation, such as digitalization, conversion and the like; the digitalization and conversion results obtained after the signal modulation are sent into a logic processor for operation and control; and the signals processed by the logic processor perform optical fiber communication with the high-voltage frequency converter through optical fibers. By adopting the resistance type voltage collecting circuit, the technical problem that a high-voltage mutual inductor has large volume, large error and inaccurate control can be solved in voltage detection; in addition, the resistance division mode is used for measuring input and output voltages of the frequency converter, the effects of small volume, low cost and high reliability are achieved.

A train axle temperature monitoring system based on fluorescence fiber temperature measurement comprises a temperature alarm host and is characterized by further comprising at least one temperature collection unit connected with the temperature alarm host through a communication and power bus, wherein the temperature collection units are connected with at least one fluorescence fiber temperature measurement probe, and the fluorescence fiber temperature measurement probes are installed at the portions needing temperature measurement. The train axle temperature monitoring system based on fluorescence fiber temperature measurement is accurate in temperature measurement and good in electromagnetic interference resistance, has the fault judgment and alarm functions and can be refitted from an existing temperature measurement network on a train; furthermore, connection and communication are reliable, and temperature measurement inaccuracy and faults caused by demultiplexing and multiplexing of the train are avoided.

The invention discloses an intelligent direct-current stabilized power supply. The intelligent direct-current stabilized power supply comprises an AC/DC (alternating current/direct current) converting circuit module, a single-chip switch power source connected with the AC/DC converting circuit module, a power source output circuit module connected with the single-chip switch power source, a voltage detecting circuit module, a current detecting circuit module, a rectifying filter circuit module connected with the voltage detecting circuit module and the current detecting circuit module, a signal time division multiplexing circuit module connected with the rectifying filter circuit module, an A/D (analog to digital) converter circuit module connected with the signal time division multiplexing circuit module, a temperature sensor used for detecting internal temperature of an intelligent charger, a controller module connected with the A/D converter circuit module and the temperature sensor, a key circuit module, a display circuit module and a sound-light alarming circuit module, wherein the key circuit module, the display circuit module and the sound-light alarming circuit module are connected with the controller module. The intelligent direct-current stabilized power supply is simple in structure, reasonable in design, high in efficiency, low in cost, good in anti-electromagnetic interference performance, energy-saving, environmental-friendly, strong in practicability, and convenient to popularize and use.

The invention discloses an isolator, and relates to the field of isolators. The circuit comprises a control circuit, and an oscillation circuit, a coupling transmission circuit, a demodulation circuitand an output circuit which are connected in sequence, the oscillation circuit is provided with a signal input end, a first grounding end and a control end, and the output circuit is provided with asignal output end and a second grounding end. The isolator provided by the invention has four ports, can be compatible with a four-port optical coupler, greatly improves the anti-electromagnetic interference performance of the isolator, and has the advantages of small chip size, low power consumption, good anti-electromagnetic interference performance and high reliability.

The invention provides a spread spectrum clock signal generating circuit and a switching power supply converter, comprising a first reference voltage source, an adjustable current source unit, a counter and an oscillator, wherein the oscillator comprises a comparator and a first capacitor; the adjustable current source unit is used for charging or discharging the first capacitor, a charging current output to the first capacitor is gradually increased in a charging process and a discharging current output to the first capacitor is gradually increased in a discharging process, or the charging current output to the first capacitor is gradually reduced in the charging process and the discharging current output to the first capacitor is gradually increased in the discharging process, so that aspread spectrum clock signal output by the comparator is a triangular sawtooth wave clock signal. Compared with a triangular wave spread spectrum clock signal, the triangular sawtooth wave spread spectrum clock signal has better attenuation effect on electromagnetic wave interference, thus anti-electromagnetic interference effect of the spread spectrum clock signal generating circuit provided by the invention is better.

The invention discloses a crack simulation calibration device based on fracture mechanics and optical fiber sensing, and relates to the field of engineering structure health monitoring. The invention aims to solve the problem that the stress of a crack cannot be detected due to lack of a device for simulating the crack of an engineering material in the prior art. An upper test plate and a lower test plate are in lap joint in the vertical direction, the lap joint position is used for simulating a crack, a fixed support is fixed to one side face of the lower test plate, an R-direction sliding table is arranged on the fixed support, a Y-direction sliding table is arranged on the R-direction sliding table, a Z-direction sliding table is arranged on the Y-direction sliding table, and the Z-direction sliding table is fixedly connected with one side face of the upper test plate; an optical fiber sensor is used for sensing the strain or wavelength change caused by the gap generated by the upper test plate and the lower test plate; and optical fiber sensing equipment is used for receiving and displaying strain or wavelength of the optical fiber sensor, and is also used for establishing displacement generated by at least one of the Z-direction sliding table, the Y-direction sliding table and the R-direction sliding table and a strain or wavelength change relationship corresponding to the displacement. The device is used for crack simulation and calibration.

The present invention provides a road-use optical fiber grating interlayer relative horizontal displacement sensor. According to the technical scheme of the invention, the test on the relative horizontal displacement between layers inside a pavement structure is realized. A top cover is embedded into the bottom of an upper-layer structure. A center column is connected with a top cover and a uniform strength beam, so that the top cover and the uniform strength beam move together. A bottom plate is embedded into the top of a lower-layer structure, and monitors the mutual displacement condition of the above two layers. A fixed ring is used for fixing the top cover and the bottom plate. Under the fixation of the fixed ring, only a tangential displacement is generated between the top cover and the bottom plate, so that the top cover and the bottom plate are not mutually separated. A silica gel pad is placed between the fixed ring and the bottom plate to limit the rotation of the bottom plate and the top cover, so that the top cover and the bottom plate are rebounded after the displacement. A fixed plate is used for fixing the silica gel pad of and other structures, so that the silica gel pad of and other structures are located inside the bottom plate. The uniform strength beam converts the horizontal sliding generated by the sensor into the vertical displacement. A sliding groove is arranged in the bottom plate and a glass cover plate is covered onto the sliding groove to increase the scratch resistance thereof. An optical fiber grating is stuck onto the uniform strength beam by a special structural adhesive, and the deformation of the uniform strength beam is converted into the wavelength change of the optical fiber grating.

The present invention relates to a maximum principal stress sensor of road fiber grating. The test of the maximum principal stress in the pavement structure can be realized. The sensor comprises spherical housing; a liquid chamber arranged in the spherical housing and consisting of a cavity body and internal fillers; elastic membranes which are fixed at two sides of the liquid chamber through fixed rings and have a force fiber grating arranged at the middle; and a compensation fiber grating arranged at the other side of the elastic membranes and configured to compensate the measurement error caused by the surrounding environment temperature of the sensor. Compared to a traditional sensor, the stress sensor provided by the invention can measure the pavement structure maximum principal stress, has the measurement result which cannot be influenced by the stress direction, is provided with temperature compensation, is easy in laying networking and wide in application range and can realize the remote distance monitoring, etc.

The invention relates to an intelligent broadcasting-station voltage-stabilized power supply. The power supply comprises a rectangular box body with an open end. A bottom plate in a box body is cooperatively connected to a main circuit board. An electronic component group is cooperatively connected to an internal portion of the box body. The electronic component group and the main circuit board are conducted, cooperated and welded. The open end of the box body is cooperatively connected to a button panel. A button circuit board is cooperatively connected to the button panel. The button circuit board and a main circuit board lead are connected and cooperated. An outer side of the open end button panel of a shell is cooperatively connected to a box body pinch plate. Two side walls of the box boy are provided with two groups of buckling components respectively. The box body is connected to the box body pinch plate in a buckling mode through the buckling components of the two sides. The structure is simple, the design is reasonable, efficiency is high, cost is low, anti-electromagnetic interference performance is good, energy saving and environmental protection are achieved, practicality is high and popularization and application are convenient.

The invention discloses a composite optical fiber communication system based on PROFIBUS bus, which comprises an upper control computer, a photoelectric conversion module and a plurality of transmission control points. Wherein the photoelectric conversion module comprises a first photoelectric conversion module, a second photoelectric conversion module and a third photoelectric conversion module.The signal input terminal of the first photoelectric conversion module is connected with an upper controller, the signal output terminal of the first photoelectric conversion module is respectively connected with the signal input terminal of the second photoelectric conversion module and the signal input terminal of the third photoelectric conversion module, the signal output terminal of the second photoelectric conversion module is connected to one group of the plurality of transmission control points, the signal output terminal of the third photoelectric conversion module is connected to theother group of the plurality of transmission control points, and the signal output terminal of the second photoelectric conversion module is connected to the signal output terminal of the third photoelectric conversion module. The technical scheme of the invention enhances the communication signal, improves the anti-interference ability of the network, effectively reduces the communication burdenof the PROFIBUS network, and improves the stability of the communication system.

The invention discloses an electromagnetic interference resisting electric gearbox. The electromagnetic interference resisting electric gearbox comprises a housing, a shaft and an electric speed change component; the electric speed change component comprises a rotating shaft gear, an electric stator, a key slider and an armature, wherein the key slider is arranged on a shaft in a sleeving manner and can move in the axial direction; the armature is fixedly arranged on the key slider; the rotating shaft gear and the key slider are arranged close to each other; the opposite end faces of the rotating shaft gear and the key slider are correspondingly provided with end face teeth and disc surface teeth, wherein the end face teeth and the disc surface teeth can be engaged with each other; the periphery of the rotating shaft gear is provided with peripheral teeth; the electromagnetic interference resisting electric gearbox is characterized in that the electric stator is fixedly arranged on thehousing of the gearbox and is arranged in a manner of being axially opposite to the armature positioned on the key slider; the electric stator always keeps a clearance with the rotating shaft gear and the armature; and excluding the surface, opposite to the electric stator, of the armature, the rest surfaces of the armature are each peripherally provided with a magnesium insulating part. The electromagnetic interference resisting electric gearbox has the characteristics of good electromagnetic interference resistance, stable work, high reliability, good safety, compact structure, small size,relatively low cost, small abrasion, long service life and the like.

The invention discloses a metalized fiber bragg grating stress sensor suitable for cold-rolled sheet shape detection, and relates to the technical field of optical fibers and optical devices and the field of metal cold-rolling processing equipment. The sensor comprises a cylindrical base with an upward opening, an elastic metal disc arranged at the opening of the cylindrical base and fixedly connected with the opening of the cylindrical base, and a pressure contact cap fixedly connected to the upper surface of the elastic metal disc and provided with a downward opening, a metalized fiber bragg grating which is fixedly connected in a space enclosed by the cylindrical base, the elastic metal disc and the pressure contact cap; the metalized fiber bragg grating extends upwards from the interior of the cylindrical base, penetrates through the thickness of the elastic metal disc, enters the interior of the pressure contact cap, extends downwards, penetrates through the thickness of the elastic metal disc and returns to the interior of the cylindrical base. The sensor is simple in processing technology, low in cost and stable in work, the phenomenon that the sensitivity of the sensor is reduced due to stress transmission loss is reduced, and the application range of equipment is expanded.

A double-furnace alternate continuous smelting system comprises a primary transformer, two smelting furnaces, a master control cabinet, rectifier cabinets, capacitor boxes and inverter cabinets. The rectifier cabinets, the capacitor boxes and the inverter cabinets are matched with the smelting furnaces respectively. The master control cabinet is provided with a high-voltage chamber and a low-voltage chamber, two electric reactors are arranged in the high-voltage chamber, and a power module and two smelting furnace master control boards corresponding to the two smelting furnaces are arranged inthe low-voltage chamber. A circuit breaker, a secondary transformer and a three-phase uncontrollable rectifier circuit are arranged in each rectifier cabinet. An LC filter circuit, a capacitance component and a voltage sampling circuit are arranged in each capacitor box. A drive circuit, an inverter circuit and a current sampling circuit are arranged in each inverter cabinet, and an output side of each inverter circuit is connected with the corresponding smelting furnace through an interlock switch. The double-furnace alternate continuous smelting system is low in cost, safe in operation, great in anti-electromagnetic interference performance and high in automation degree, simultaneous power supply to the two smelting furnaces is realized, onsite control of one smelting furnace in smelting and the other melting furnace in heat preservation is realized, and accordingly smelting efficiency is greatly improved through the alternate operation.