65results about How to "Eliminate common mode interference" patented technology

The invention belongs to the field of tunnel engineering, and particularly relates to an indoor model experience device with an existing tunnel affected by double subway construction. The experience device mainly comprises a subway excavation simulating device, a tunnel model, a strainometer, a displacement support frame, a displacement meter, and the like. A hollow aluminum pipe is arranged in the middle of the tunnel excavation simulating device, a rubber membrane filled with water is arranged on the periphery of the tunnel excavation simulating device, and soil deformation which is caused by the tunnel excavation is simulated by drainage of water with a certain size. The tunnel model is simulated by aluminum alloy pipes, and the outer wall of the tunnel model is pasted with the strainometer in a full-bridge mode to achieve strain measurement on the existing tunnel. The displacement meter is fixed on the displacement support frame, and measurement on longitudinal settlement of the existing tunnel can be achieved. The indoor model experience device with the existing tunnel affected by the double subway construction can conveniently and effectively simulate the existing tunnel deformation caused by the double subway construction of a city, and has important reference value for establishing a tunnel construction security traversing technology standard and an adjacent structure security protective measurement.

The invention relates to a railway track detection device and a use method. The broken rail detection device comprises two steel rails of a rail-mounted locomotive, and is mainly characterized in that at least a pair of electric short wires are arranged between the two steel rails; the electric short wires and the two steel rails surround into an electrical isolation unit; at least one current sensor is arranged on one steel rail of the electrical isolation unit; and the current sensor is electrically connected with a current signal receiving and processing unit which outputs a broken rail signal to an output device. The invention has the advantages of adopting a direct short-circuit jointless track circuit; the circuit can not be used as the traditional track circuit although a shunt dead section exists; and the jointless track circuit is superior in the broken rail detection aspect because of the simple device thereof.

The invention discloses a brain electricity collecting device which particularly comprises an N-channel brain electricity collecting electrode, a brain electricity signal collector, a transmission module and a data receiving module. Brain electricity signals acquired by the N-channel brain electricity collecting electrode are fed into a high-impedance front buffer stage and then are converted into digital signals by a high-precision brain electricity collecting and converting module, the digital signals are transmitted into a digital signal processor, and processed signals are transmitted to the data receiving module according to particular requirements. The brain electricity collecting device has the advantages that the brain electricity collecting device is particularly provided with a 24-bit high-precision analog-digital conversion chip to directly acquire signals of relevant positions of the brain of a person, and digital signals converted by corresponding channels are subtracted from the signals, so that common-mode interference, device noise and other relevant background noise can be eliminated, and basically pure brain electricity signals can be obtained.

A traceable synchronous measurement ruler-based mixed double-light source laser range finding device and method belongs to the technology of phase laser range finding. The range finding device comprises a measurement ruler generation unit, a laser frequency shift unit, abeam expanding collimating mirror set, a measurement optical path and a circuit unit. The range finding method comprises a step 1 of starting a frequency reference laser and a double longitudinal mode frequency stabilization He-Ne laser, a step 2 of taking one beam as a reference laser beam, and another beam as a measurement beam, a step 3 of taking a formula defined in the specification as an accurate measurement ruler, a step 4 of taking a formula defined in the specification as a rough measurement ruler, and a step 5 of moving a measurement cube-corner prism to a target end for obtaining phase differences of the accurate measurement ruler and the rough measurement ruler Phi 1 and Phi 2 respectively and obtaining a to-be-tested distance value through a formula. The invention solves a problem that a device and method for achieving large power, synchronism of multiple measurement rulers and traceability is not available in the phase laser range finding technology, and the device and method provided by the invention is characterized by being high in range finding precision and measurement efficiency, and good in stability and real-time performance.

The invention discloses an active filtration method and device for simultaneously restraining difference mode interference and common mode interference. The method comprises the following steps that (1) a plurality of active power filters are respectively bridged between each power supply bus and each neutral line, and meanwhile, a current sensor is arranged on each power supply bus, and each current sensor is respectively connected to the corresponding active power filter bridged between each power supply bus and each neutral line; (2) each current sensor monitors harmonic interference current on each power supply bus; and (3) each active power filter works based on a feedback control principle, so that the harmonic interference current on the power supply bus, which is monitored by each corresponding current sensor, is minimum, and meanwhile, the harmonic current of the neutral line is minimum. According to the active filtration method and device, through a connection way of two active power filters and the ground wire, a certain compensation harmonic current is injected into the power supply buses, and meanwhile, the difference mode interference and the common mode interference on the power supply buses are removed, and the low-frequency interference conduction and radiated emission quantity of the long distance transmission cable of the power grid can be effectively controlled.

A multi-frequency aliasing prevention traceable synchronous measuring tape double-light-source laser ranging device and method belongs to the phase laser ranging technology. The device comprises a measuring tape generating unit, a laser frequency shift unit, a beam expanding collimation lens group, a measuring light path and a circuit unit. The method comprises the steps of, firstly, starting a frequency reference laser device, a double-longitudinal-mode frequency stabilization He-Ne laser device and a semiconductor laser device; secondly, taking one beam as a reference laser beam and taking the other beam as a measuring laser beam; thirdly, taking c/Iv2-v3I as a fine measurement tape; fourthly, taking c/Iv1-v2I as a rough measurement tape; fifthly, moving a measuring pyramid prism to a target end to obtain the phase differences (i) phi (/i) 1 and (i) phi (/i) 2 of the fine measurement tape and the rough measurement tape; lastly, obtaining a measured distance value through formulas. The multi-frequency aliasing prevention traceable synchronous measuring tape double-light-source laser ranging device and method solves the problems that superlong wavelengths and ultrashort wavelengths cannot be generated synchronously and laser tapes are incapable of performing direct tracing and have nonlinear periodic errors and frequency aliasing, and has the advantages of being high in measuring efficiency, precision, stability and practicality.

A double-longitudinal mode laser ranging device and method based on traceable synchronous measuring tapes belongs to phase laser ranging technology. The ranging device includes a measuring tape generation unit, a laser frequency shift unit, a beam-expanding collimating lens group, a measuring light path and a circuit unit. The ranging method includes the following steps: step one, starting a frequency reference laser and a double-longitudinal mode frequency stabilization He-Ne laser; step two, using one beam as a reference laser beam, and using the other beam as measuring laser; step three, using c/|v2-v3| as a precise measuring tape; step four, using c/|v1-v2| as a rough measuring tape; and step five, moving a measuring cone prism to a target end, obtaining phase differences phi1 and phi2 of the precise measuring tape and the rough measuring tape respectively, and finally obtaining measured distance values through formulas. The double-longitudinal mode laser ranging device and method based on the traceable synchronous measuring tapes in the invention solves the problem that phase laser ranging technology lacks a laser ranging device and method capable of giving consideration to large power, multi-measuring tape synchronization and traceability, and has the characteristics of high ranging precision, high measuring efficiency, and strong stability and real-time performance.

The invention discloses a non-contact reversing contactor, and belongs to the technical field of motor control. The non-contact reversing contactor comprises three phases of power supplies A1, B1 and C1 at an input end, three phases of power supplies A2, B2 and C2 at an output end, a positive thyristor group and a negative thyristor group, and is characterized by also comprising a singlechip unit and an interlocking module in (a) software or/and hardware form(s), wherein the singlechip unit controls the switching-on/off of the positive and negative thyristor groups through the interlocking module, and makes the positive and negative thyristor groups asynchronously in an on state. According to the non-contact reversing contactor, due to the adoption of the singlechip unit, control accuracy is improved; and the singlechip unit controls the switching-on/off of the positive and negative thyristor groups through the interlocking module, so that interlocked switching-on control over the positive and negative thyristor groups is realized, and a phase fault caused by the simultaneously switching-on of the positive and negative thyristor groups is avoided.

The invention provides a differential charge amplifier with high precision, low temperature drift and low offset, the differential charge amplifier has the advantages of high amplification precision on charge signals, small temperature drift and low offset voltage, and can be used for accurately amplifying vibration charge signals. The amplifier structurally comprises an overload protection circuit, a differential charge conversion circuit, a low-pass filter circuit and a high-pass filter circuit, which are connected in sequence, and a power supply conversion circuit used for supplying power to the circuits, wherein the differential charge conversion circuit comprises a first inverting amplifying circuit, a second inverting amplifying circuit and a subtraction operation circuit; a Qp anode and a cathode of a charge signal are respectively connected to the first inverting amplifying circuit and the second inverting amplifying circuit through capacitors, and the feedback resistance branches of the two inverting amplifying circuits respectively form T-shaped networks with the same RC series branch; the outputs of the first inverting amplifying circuit and the second inverting amplifying circuit serving as a positive phase input and a negative phase input are respectively connected to the subtraction operation circuit.

The invention provides a high-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement device and method and belongs to a phase laser distance measurement technology. The high-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement device comprises a measuring ruler generation unit, a laser frequency shifting unit, a beam expanding collimation lens group and a light path and a circuit measurement unit. The high-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement method comprises step 1, opening a frequency standard laser and a semiconductor laser; step 2, serving one beam as a reference laser beam and serving the other beam as a measurement laser beam; step 3, serving a formula as an accurate measurement ruler; step 4, serving a formula as a rough measurement ruler; step 5, moving a measurement prism to a target side to obtain the phase difference Phi 1 of the rough measurement ruler and the phase difference Phi 2 of the accurate measurement ruler and obtaining a measured distance value through a formula. According to the high-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement device and method, the problem that the multi-measurement-ruler synchronicity and traceability of devices and methods cannot be integrated in the phase laser distance measurement technology is solved, the accuracy of distance measurement is high, the measurement efficiency is high, and the stability and the real-time performance are high.

The invention discloses a one-gun multi-beam welding control device and method of an electron beam welding machine. The device mainly comprises a central control unit, a deflection scanning driving power supply, a deflection scanning winding, an optical fiber driving power supply, optical fibers, an electron beam flow control unit, a first electron beam flow sampling resistor and a second electron beam flow sampling resistor. The one-gun multi-beam welding control device and method of the electron beam welding machine have the advantages that electron beam flow closed-loop control can be realized at a high-voltage end and the adjusting speed is fast; by using the optical fibers for transmitting signals, high-voltage insulation isolation is realized; by using two loops of analog optical fibers and transmitting signals through a differential mode, common-mode interference caused by change of transceiver device performance is eliminated; an electron beam flow is simultaneously sampled at a high-voltage end and a low-voltage end, and the nonlinearity of an electron beam flow control system and the drift of the working point of the electron beam flow control system are corrected by the central control unit; and excessive scanning traces left by electron beams when the electron beams move among different points in the one-gun multi-beam welding process are eliminated.

The invention relates to a mixed heterodyne multi-frequency anti-aliasing laser ranging device and a mixed heterodyne multi-frequency anti-aliasing laser ranging method, belonging to a phase laser ranging technology. The ranging device comprises a measuring ruler generating unit, a laser frequency shifting unit, an anti-aliasing measuring light path and a phase measuring unit. The ranging method comprises the following steps: step one, starting a frequency standard laser, an offset frequency locking semiconductor laser and a He-Ne laser; step two, taking a beam as a reference laser beam, and the other beam as measuring laser; step three, taking c/|v2-v3| as accurate measuring ruler length; step four, taking c/|v1-v2| as rough measuring ruler length; and step 5, moving a measuring retroreflector to a target end to respectively obtain phase difference phi 1 and phi 2 of the accurate measuring ruler and the rough measuring ruler, and finally obtaining a measured distance value through a formula. The mixed heterodyne multi-frequency anti-aliasing laser ranging device and the method provided by the invention solve the problems that ultralong wavelength and ultrashort wavelength cannot be generated simultaneously, the laser measuring ruler cannot realize direct traceability, and nonlinear periodical error and frequency aliasing are caused, and has the characteristics of high measurement efficiency, high precision, and strong stability and real-time property.

A high-precision synchronous mixed heterodyne-mode phase laser range finding device and method belongs to the phase laser range finding technology. The range finding device comprises a measurement ruler generation unit, a laser frequency shift unit, a beam expanding collimating mirror set, and a measurement light path and circuit unit. The range finding method comprises a step 1 of starting a frequency reference laser and a double longitudinal mode frequency stabilization He-Ne laser, a step 2 of taking one beam as a reference laser beam, and another beam as a measurement beam, a step 3 of taking a formula defined in the specification as an accurate measurement ruler, a step 4 of taking a formula defined in the specification as a rough measurement ruler, and a step 5 of moving a measurement cube-corner prism to a target end for obtaining phase differences of the accurate measurement ruler and the rough measurement ruler Phi 1 and Phi 2 respectively and obtaining a to-be-tested distance value through a formula. The invention solves a problem that a device and method for achieving synchronism of multiple measurement rulers and traceability is not available in the phase laser range finding technology, and the device and method provided by the invention is characterized by being high in range finding precision and measurement efficiency, and good in stability and real-time performance.

The invention discloses a ceramic adapter plate for improving temperature characteristics of a differential silicon vibration beam accelerometer. The adapter plate comprises an adapter plate body; anda cross-shaped through hole is formed in the middle of the adapter plate body. Four metal right-angle frame lines are printed on the surface of the adapter plate body; and the four metal right-angleframe lines and the edge of the cross-shaped through hole form four rectangular bonding faces jointly and the whole structure is in central symmetry. According to the invention, the ceramic adapter plate has the following advantages: the adverse effect of the fluidity of an adhesive on the shape of the contact part of an adhesive layer and a chip is eliminated; the symmetry of the overall structure of the differential silicon vibration beam accelerometer after four points are coated with adhesives is improved; and the accelerometer gives full play to the inhibition effect on the common-mode interference caused by thermal stress, so that the temperature performance of the accelerometer is improved.

The invention provides a hybrid laser ranging device and method based on traceable simultaneous multiple measurement tapes, belonging to the technology of phase laser ranging. The ranging device comprises a measuring tape generation unit, a laser frequency shift unit, an expanded beam collimation lens group, a measuring light path and a circuit unit. The ranging method comprises the following steps of (1) starting a reference frequency lasers and a semiconductor laser, (2) taking one beam as a reference laser beam, and taking the other beam as measurement laser, (3) taking c/|v2-v3| as a fine measurement tape, (4) taking c/|v1-v2| as a crude measurement tape, (5) moving a measurement retroreflector to a target end, obtaining the phase differences phi 1 and phi2 of the crude measurement tape and the fine measurement tape respectively, and finally obtaining a measured distance value through a formula. According to the device and the method, the problem that a device and a method with the consideration of synchronization and traceability of multiple measurement tapes are lacked in the phase laser ranging technology is solved, and the device and the method have the characteristics of high ranging precision, high measurement efficiency, high stability and high real-time performance.

The invention provides an electronic device. The electronic device comprises a USB interface circuit and a main control chip, and the USB interface circuit is connected with the main control chip andis used for realizing communication connection between the main control chip and a USB device. The USB interface circuit further comprises a USB interface, a switching driver and a filter circuit. TheUSB interface is used for being connected with the USB device in an inserted mode so as to establish electrical connection, wherein the switching driver is electrically connected between the USB interface and the main control chip, and the switching driver drives signals transmitted between the USB device and the main control chip according to a preset coefficient; the filter circuit is electrically connected between the USB interface and the switching driver, and the filter circuit is used for filtering common-mode interference between the USB interface and the switching driver. Therefore, the plugged USB device can be effectively identified.