39results about How to "Frequency response width" patented technology

The invention relates to a multiple-spindle ratchet wheel strain testing system and method of a pipe bend. The applied load F and output pressure P of a hydraulic servo fatigue testing machine are jointly controlled by a microcomputer and a sensor so as to provide various complex load working conditions, and a real-time multiple-spindle ratchet wheel action of the bend under the complex load working conditions is measured by a stain gauge method; and the variation situation of strain applied to the bend is measured by utilizing the sensor to control the hydraulic servo fatigue testing machine, a clamping fixture auxiliary mechanism and the strain gauge method, data is collected by a multi-channel dynamic strain instrument, and the result is output through the computer. According to the invention, multiple complex load combination working conditions can be provided, the load working conditions and the application range are wide, the measurement position can be adjusted flexibly, namelythe strain gauge sticking position can be selected freely according to concrete test designs, and is not restricted by the test conditions; the test result has high accuracy, the data curve is smoothad stable, and the design is reasonable; and the multi-channel dynamic strain instrument has the characteristics of low drift, low noise and wide frequency response.

The invention discloses a method of testing mechanical properties of coal in coal-rock composite under dynamic loading and combined static and dynamic loading. An existing coal-rock composite test piece is used; starting from rock less prone to crushing, an SHPB (split Hopkinson pressure bar) test device is used, coal-rock composite loading test is performed by means of attaching a strain gauge, stress of coal is acquired according to stress at each end face of the coal test piece, and stress variation of the coal in the coal-rock composite under dynamic loading. Mechanical properties of coal in a certain surrounding rock environment are acquired, better guidance can be provided for field engineering practice, and the method has major guiding significance for disclosing true failure mechanism of engineering coal.

The invention relates to a device for testing kinetic energy of a spraying water drop. The device comprises a sensor water receiving module, a signal conditioning module, a data collection module, a computer and a data analysis module, wherein the data analysis module is arranged inside the computer, the sensor water receiving module comprises a substrate, an array sensor which is composed of a plurality of piezoelectric membranes is arranged on the substrate, the sensor water receiving module us arranged below spraying water, a sensor outputs a sensed electric charge quantity Q through a forward electrode output end of the sensor after the sensor senses the water drop, a reverse electrode output end of the sensor is grounded, the signal conditioning module comprises an impedance conversion unit and an amplification unit, the impedance conversion unit is used for converting the electric charge quantity Q sensed by the sensor into a voltage quantity U<0> for output, the amplification unit is used for amplifying the voltage quantity U<0> output by the impedance conversion unit and outputting a voltage quantity U<out>, and the data collection module obtains the voltage signal U<out> output by the amplification unit in real time and inputs the voltage signal U<out> into the computer after analog-to-digital (A / D) conversion. The device is widely applicable to kinetic energy tests of spraying water drops in little sprinkling irrigation projects.

The invention discloses aircraft laminate structure striking -load spectrum monitoring method. It includes the following steps: cling or pre-embedding many piezoelectricity sensing elements on the surface of the laminate structure as diverging piezoelectricity board unit; while suffering random striking, data collecting processing integration board collects the dynamic response of the sensor; calculating out structure modality response coordinate; using unconditional stability fine step-by-step integration method to find out modality dynamics differential equation; iteration calculating out striking load time course by modality coordinate. The monitoring device of the invention includes computer, diverging piezoelectricity sensor and is connected with charge amplifier which is connected with computer by data collecting machine. The computer main board expanding groove is inserted data collecting processing integrating board.

The invention relates to a straight tube multi-axis ratchet wheel strain testing system and a straight tube multi-axis ratchet wheel strain testing method. A hydraulic servo fatigue tester, a quasi three-point bent clamp and a strain gauge method measurement straight tube are controlled by using a sensor, data are acquired through a multi-channel dynamic strain meter, and results are output through a computer. According to the method, the testing position is flexible, and the load working conditions are diverse; and the method is novel, the design is reasonable, and the data are accurate and reliable. Meanwhile, the multi-channel dynamic strain meter has the characteristics of low drift, low noise and broad frequency response; and the fatigue tester has the functions of presetting, measuring, controlling and automatically recording the testing conditions and the testing parameters and automatically giving an alarm and halting the machine when the test is invalid or abnormal, can be widely applied to test and research of the evolution laws of multi-axis ratchet wheel strain of a pressure straight tube under various complex working conditions such as earthquake or temperature change of fluid in the tube and the like, and can be used for determining the ratchet wheel boundary of the straight tube.

The invention relates to a true-root-mean-square capacitive current tester. After a power supply is plugged into a power socket, the power socket transmits power energy to a low-voltage side coil of a test transformer through a main power switch and a test switch, a high-voltage end on a high-voltage side of the test transformer is connected with a high-voltage test cable and is connected in parallel with a serial circuit composed of voltage dividing resistors R1 and R2, a low-voltage end on the high-voltage side of the test transformer is connected with the input end of a current sensor, and a node between the voltage dividing resistors R1 and R2 is connected with the input end of a voltage sensor. The input end of a switching power supply is connected with the output of the main power switch, the output of the switching power supply respectively powers a single chip microcomputer, the current sensor and the voltage sensor, the output ends of the current sensor and the voltage sensor are respectively connected with a signal acquisition end of the single chip microcomputer, and the output of the single chip microcomputer is respectively connected with a voltage display meter, a voltage display meter and a capacitive current display meter. True root mean square measurement on voltage and current is carried out by the sensors, data processing is carried out by the single chip microcomputer, and the true-root-mean-square capacitive current tester has the advantage of high precision, high isolation, broad frequency response and low drift.

The invention discloses a passive negative pressure adsorption micro-miniature wall-climbing robot foot mechanism with a touch sense. The robot foot mechanism comprises a control system and a foot rod connected with a leg of a robot, the lower end of the foot rod is connected with an adsorption mechanism through an ankle joint, the adsorption mechanism comprises a rigid supporting body, lip edges made of an elastic material, a filter screen, a stepping motor, a gear and a polyvinylidene fluoride piezoelectric film sensor, the piezoelectric film sensor comprises three piezoelectric films which are annularly and uniformly attached to the inner sides of the lip edges, the total pressure value between the robot and the wall surface can be measured, and the flatness of the wall surface can be sensed; and the control module is used for adjusting the size of the adsorption force of the foot mechanism and the rotation angle of the ankle joint according to the information fed back by the sensor, so that the wall-climbing robot can adapt to the curvature change of the wall surface and stably adsorb on the wall surface. The foot mechanism is small in size, simple in structure, does not need a vacuum source and has certain adsorption capacity, so that the foot mechanism can be used as the foot mechanism of a micro-miniature wall-climbing robot.

The invention provides a communication method, device and system for a Bluetooth device. The Bluetooth device comprises a first terminal and a second terminal which establishes Bluetooth communication connection with the first terminal. The first terminal determines a valid idle channel. The first terminal switches to the valid idle channel. The first terminal sends frequency information of the valid idle channel to the second terminal through Bluetooth, so the second terminal can switch to the valid idle channel according to the frequency information of the valid idle channel. The first terminal transmits an audio modulation signal to the second terminal through the valid idle channel, so the second terminal receives and plays the audio modulation signal. According to the communication method, device and system for the Bluetooth device provided by the invention, the problem that when audio information with a high audio quality demand is transmitted between the Bluetooth devices, the audio quality playing effect is poor due to signal distortion resulting from limitation of a frequency response range is solved.

The invention discloses a distortionless sound playback system for counter electromotive force signals. The distortionless sound playback system is characterized by comprising a counter electromotive force signal loudspeaker and a counter electromotive force signal amplifier, wherein when the loudspeaker body is distorted, and the motion speed of a paper disk is deviated from a desired value under the pressure of air in a sound box or the influence of sound reflection, resonance, standing waves and harmonic factors, a sound coil in the counter electromotive force signal loudspeaker, which is connected with the paper disk, can instantly detect the generated deviation and feed back the deviation to the counter electromotive force signal amplifier; and the counter electromotive force signal amplifier instantly makes a response to rectify the deviation until the deviation completely disappears. The distortionless sound playback system is rational in design; the loudspeaker is changed into a standard four-end network provided with an input and an output; and moreover, an output signal can really reflect an electric signal of the motion of the loudspeaker, so that a power amplifier and the loudspeaker belong to a real electronic network system. The frequency response is wide and flat, and the sound is not subjected to distortion and phase shift; the counter electromotive force signal loudspeaker can replace all treble, alto and bass loudspeakers in the sound box; and therefore, the step of adjusting the troublesome frequency divider is omitted, and the manufacturing cost of the sound box is greatly reduced.

The invention relates to an on-line monitoring device for the vibration of the stator winding end of a turbogenerator set and a method for using it, and is characterized in that it is composed of an insulating box (1) and an acceleration sensor (2) arranged in the insulating box (1), and the insulating box (1) Made of epoxy resin, the insulating box (1) is provided with a cylindrical cavity, the acceleration sensor (2) is placed in the cavity, and a metal shielding layer (3) is arranged on the acceleration sensor (2). The epoxy resin cures the sensor (2) and the shielding layer (3) into a whole; the outer side of the insulating box (1) is provided with a groove (4), and the signal output end of the acceleration sensor (2) leads out of the insulating box through a shielded cable (1) outside; the insulating box (1) with the acceleration sensor (2) is bound to the wire rod nose end of the measured stator winding through the groove (4), the acceleration sensor (2) detects the vibration of the stator winding, and The vibration signal is converted into an electrical signal and transmitted to the peripheral detection equipment through the shielded cable.

The embodiment of the invention discloses a soil pressure sensor. The soil pressure sensor comprises a shell, a diaphragm, a PVDF piezoelectric film and an output wire, wherein the shell is of a cavity structure with an opening in the top, the diaphragm covers the opening, the shell is filled with filling liquid, the PVDF piezoelectric film is arranged in the shell and suspended in the filling liquid, one end of the output wire is connected to the PVDF piezoelectric film, and the other end of the output wire extends out of the shell. The soil pressure sensor is wider in application range and high in detection precision.

The invention relates to the technical field of microphone sound head, in particular to a sound head polar plate of microphone, which includes a polar plate as well as a step through hole, a blind hole, a screwed hole, a chute, a screwed blind hole and an insulating post arranged on the polar plate; the central part of the polar plate is provided with a central hole; the surrounding of the central hole is provided with a plurality of through holes which are uniformly distributed; the polar plate is characterized in that the appearance of the polar plate is elliptical; the length of the long axis of the polar plate is 45mm-11mm and the length of the short axis of the polar plate is 44mm-10mm; the diameter of the through hole is 0.7-1.3mm; the through holes are arranged with mutually symmetrical central horizontal line and vertical line of the polar plate; compared with the prior art, the sound head polar plate of elliptical microphone has simple and novel structure, wide frequency response, flat frequency response, higher frequency response characteristics and directivity, and changes the sound head structure of the previous traditional microphone. Besides, the sound head polar plate of elliptical microphone is simple to be manufactured with obvious effects, and is worthy of popularization and application.

The invention provides a skull conduction device composed of vibration transducer using HTD as main body and audio frequency phase shift booster amplifier adapter circuit matched therewith. The audio frequency phase shift circuit, power amplification circuit, booster matching circuit and vibration transducer are serially connected; the audio frequency phase shift circuit is inputted by audio frequency electrical signal at input end; the output end of boost matching circuit connects with vibration transducer. The vibration transducer comprises a HTD with a central hole; copper substrate 3 serving as anode of the transducer, silver plating layer 4 serving as cathode of the transducer separately connects with two output end of boosting transformer at two sides of piezoelectric material 2 of HTD. Nylon bolt 5 passes nylon gasket 6, HTD and fastens with nut 8. The fastened HTD outer layer is wrapped and sealed by silica gel 7, thereby reducing sound leakage and possessing relatively better water-proof and anti-impact performance.

The invention discloses a frequency modulation anti-interference hidden earphone system which is used for being connected with an interphone so as to obtain an audio signal and conducting FM on the audio signal. The frequency modulation anti-interference hidden earphone system comprises an adapter and earphones. The adapter comprises an interface module, a power module, an audio quality detection module, a gain control module, an FM module and a signal amplification module. The interface module is connected with the interphone, the audio quality detection module and the gain control module. The gain control module, the FM module and the signal amplification module are connected in sequence. The signal amplification module is connected with the earphones wirelessly. According to the frequency modulation anti-interference hidden earphone system, after FM is conducted on the audio signal, the audio signal is transmitted to the earphones, demodulated through the earphones, processed through a DSP and then played. Compared with existing AM, FM has the advantages of being smaller in distortion, wide in frequency response, high in signal-to-noise ratio, high in amplification efficiency, better in noise resistant effect and capable of improving the tone quality. The audio signal is stabilized through the gain control module so that the communication quality can be improved.

The invention discloses a foam material or soft material dynamic performance measurement method, for the foam material or soft material dynamic performance measurement. First, divide the transmission pole of the Hepuxinsen strut into two sections, and then take a thickness of 10-60 mum piezoelectric film, and affix the micron-level insulation membrane on its both sides, and then paste the piezoelectric film with insulation membrane sandwiched between two transmission poles, and the section of the transmission pole near the specimen is equipped with a one-way limiter in the center, and the one-way limiter is fastened with the transmission pole by the clip fixture; put another section of the transmission pole close to fixed stationary energy absorber through the rubber pad, and the rubber pad modulates the pre-tension through the piezoelectric film; electrical connect the piezoelectric film output electrode and the impedance converter; add sample loading, and through the output of impedance converter to obtain foam material or soft material dynamic force or stress force value. The invention uses the piezoelectric film, making dynamic performance measurement of foam or soft material simple and easy, and with high measurement sensitivity.

The invention discloses a low-energy-consumption high-pollution-resistance ultrahigh-frequency-response digital hydraulic servo control system and a control method. The system comprises digital hydraulic switch valves, a hydraulic cylinder, a displacement sensor, pressure sensors and a digital controller, main pressure oil is respectively connected with main pressure oil ports of a first digital hydraulic switch valve and a second digital hydraulic switch valve, main return oil is respectively connected with secondary pressure oil ports of a third digital hydraulic switch valve and a fourth digital hydraulic switch valve, a secondary pressure oil port of the first digital hydraulic switch valve and a main pressure oil port of the third digital hydraulic switch valve are respectively connected with a hydraulic cylinder piston cavity oil port, a secondary pressure oil port of the second digital hydraulic switch valve and a main pressure oil port of the fourth digital hydraulic switch valve are respectively connected with a hydraulic cylinder rod cavity oil port, the displacement sensor, a first pressure sensor and a second pressure sensor are respectively connected with a comparator, and a signal generator is respectively connected with magnet exciting coils of the four digital hydraulic switch valves. According to the system, ultrahigh-frequency fluid pulse signals are directly converted, and therefore accurate control of hydraulic servo is realized.

The invention discloses a test method for the mechanical properties of coal in a coal-rock combination under dynamic and dynamic and static combined loads. The existing test piece of the coal-rock combination is used to start with rocks that are not easy to be crushed, and the SHPB test device is used. The coal-rock combination is tested by pasting strain gauges, the stress of the coal is obtained from the stress at both ends of the coal specimen, and the coal-rock combination under dynamic load is obtained by inverse calculation based on the strain of the rock in the coal-rock combination. Variations in coal strain. The invention not only obtains the mechanical properties of coal in a certain surrounding rock environment, but also better guides on-site engineering practice, and has great guiding significance for revealing the real failure mechanism of engineering coal bodies.

The invention relates to a sensor device and method for testing the dynamic stress of an area array. The area array piezoelectric sensor consists of a number of independent piezoelectric stress sensors pasted on the flexible accessory board, the minimum spacing of which is the size of the sensor, and the wires of each sensor are collectively connected to the terminal. The sensor includes a metal protection layer, a rubber encapsulation layer, a piezoelectric film, an electrode adapter and a miniature charge amplifier. Each sensor is provided with a miniature charge amplifier and a resistor, the power input port and the signal output port are respectively connected with the amplifier, and the ground electrode of the sensor is connected with the power ground electrode. The invention includes an area array piezoelectric sensor, a connection terminal and an acquisition card, and the acquisition card is connected to a computer for data acquisition. The invention obviously improves the equivalent modulus and dynamic performance stability of the stress sensor, can accurately and simply test the dynamic stress distribution of the entire section of the subgrade, and can be used for testing the dynamic stress of the soil subgrade in fields such as railways, highways and airports.

The invention discloses a domestic sewage and dirt treater in a coal gas (CG) ultrasonic reverberation resonance field as well as a method and application for treating domestic sewage and dirt by using the treater, belongs to the technical field of water treatment, and particularly relates to a domestic sewage and dirt treater in the CG ultrasonic reverberation resonance field as well as a method and application for treating sludge / sewage by using the treater. The invention aims to solve the problem that the conventional equipment for treating the sludge and sewage by utilizing an ultrasonic technique is high in energy consumption. The product comprises a sewage and dirt inlet, a sewage dirt / bubble mixing chamber, a rotary distribution plate, a bowl-type shunt cover, a CG ultrasonic reverberation resonance field generator pipe main reactor, a filtering net, a sieve plate, a seal head, a sludge outlet and a treated water outlet. The treater disclosed by the invention can be independently used for treating pollution of industrial sewage, domestic sewage, agricultural wastewater and other natural water resources in rivers, lakes and seas and the like, or can be combined with a hydrogen peroxide method, an ozone oxidization method, an active iron catalysis method, a hypochlorite method or a Fenton oxidation process to be used for treating pollution of the natural water resources.

The invention discloses a domestic sewage and dirt treater in a coal gas (CG) ultrasonic reverberation resonance field as well as a method and application for treating domestic sewage and dirt by using the treater, belongs to the technical field of water treatment, and particularly relates to a domestic sewage and dirt treater in the CG ultrasonic reverberation resonance field as well as a method and application for treating sludge / sewage by using the treater. The invention aims to solve the problem that the conventional equipment for treating the sludge and sewage by utilizing an ultrasonic technique is high in energy consumption. The product comprises a sewage and dirt inlet, a sewage dirt / bubble mixing chamber, a rotary distribution plate, a bowl-type shunt cover, a CG ultrasonic reverberation resonance field generator pipe main reactor, a filtering net, a sieve plate, a seal head, a sludge outlet and a treated water outlet. The treater disclosed by the invention can be independently used for treating pollution of industrial sewage, domestic sewage, agricultural wastewater and other natural water resources in rivers, lakes and seas and the like, or can be combined with a hydrogen peroxide method, an ozone oxidization method, an active iron catalysis method, a hypochlorite method or a Fenton oxidation process to be used for treating pollution of the natural water resources.

The invention relates to a straight tube multi-axis ratchet wheel strain testing system and a straight tube multi-axis ratchet wheel strain testing method. A hydraulic servo fatigue tester, a quasi three-point bent clamp and a strain gauge method measurement straight tube are controlled by using a sensor, data are acquired through a multi-channel dynamic strain meter, and results are output through a computer. According to the method, the testing position is flexible, and the load working conditions are diverse; and the method is novel, the design is reasonable, and the data are accurate and reliable. Meanwhile, the multi-channel dynamic strain meter has the characteristics of low drift, low noise and broad frequency response; and the fatigue tester has the functions of presetting, measuring, controlling and automatically recording the testing conditions and the testing parameters and automatically giving an alarm and halting the machine when the test is invalid or abnormal, can be widely applied to test and research of the evolution laws of multi-axis ratchet wheel strain of a pressure straight tube under various complex working conditions such as earthquake or temperature change of fluid in the tube and the like, and can be used for determining the ratchet wheel boundary of the straight tube.

The invention discloses a series feedback balance high-fidelity audio amplifying circuit. All elements are in balanced connection in an up-down hetero-polar symmetry and left-right homo-polar symmetry; in-phase output poles of four input tubes are connected to four corners of a square resistance network respectively; certain ends of two loop feedback resistors are connected with a middle point of a side edge of the square resistance network respectively, namely the middle point of the resistance of the in-phase output poles of the two input tubes in the up-down hetero-polar symmetry, and the other ends are connected with a middle point of an output end on a same side of an amplifying circuit respectively to constitute the series negative feedback balance circuit structure in complete bilateral symmetry.

The invention relates to a piezoelectric beam sensor-based fragrant pear firmness sound and vibration nondestructive detection system and a piezoelectric beam sensor-based fragrant pear firmness sound and vibration nondestructive detection method. The system consists of software and hardware systems. The software system comprises an HA-405 type voltage amplifier, a VibPilot vibration control and dynamic signal acquisition analyzer, a computer and the like. The hardware system comprises three Q220-A4-303YB type piezoelectric beam sensors, a fruit bed support material and the like. According to the system and the method, the three piezoelectric beam sensors are used for the first time, the equator part and the calyx end of a fragrant pear can be sensed at the same time, and a firmness detection model is constructed by virtue of a novel firmness evaluation method, and is free of influence of the fruit shape, so that the internal quality of the fruit can be judged more accurately and comprehensively, the grade and the commodity rate of the fragrant pear can be improved, and the problems of destructive detection, greater noise influence, high cost and the like of a fruit firmness detector on the current market are solved.

The invention relates to the technical field of loudspeaker box manufacture, in particular to a planar loudspeaker comprising a soundboard, an annular conducting coil, a soft magnet, a voice coil, a bias coil, a slide resistor Rw, a resistor R1, a super-audio oscillation circuit and a power amplification circuit. The annular conducting coil is disposed on the soundboard, the soft magnet is provided with an opening, the sound board is disposed at the opening, the soft magnet is wound with the voice coil and the bias coil, the voice coil is connected with the super-audio oscillation circuit, and the bias coil is connected with the power amplification circuit through the slide resistor Rw and the resistor R1. The planar loudspeaker has the advantages of wide frequency response, high power, small distortion, thin body, arbitrary shape, simple structure, processing convenience, difficulty in damage, no magnetic disturbance and the like.

The invention discloses a piezoelectric intelligent torsional vibration control rod. The lower end of the hollow round rod is equipped with the first connecting block, the annular piezoelectric torsion driver, and the second connecting block sequentially from top to bottom, and the upper end of the hollow round rod is equipped with the third connecting block. Sensors are mounted on the inner or outer surface of the hollow rod. When there is torsional deformation or torsional vibration at the connection end relative to the connection end, the sensor detects that the signal is amplified in reverse and sent to the ring piezoelectric torsion driver, and the ring piezoelectric torsion driver generates a torsional torque that is opposite to the torsion deformation to suppress its deformation or vibrate. The rod integrates sensing and drive control, and has the advantages of compact structure, good control characteristics, low power consumption, and good vibration suppression effect. It can be widely used in the operating rods and truss structures of space robots, and in the field of active vibration control where torsional vibration needs to be suppressed (isolated).

An analog method for measuring the current value in 0-1 MH2 range, which is flowing through human body, includes such steps as measuring the voltage drop of said current value on a resistor (1 kiloohm), pre-amplifying, offset controlling, active value transforming, linear regulating, A / D converting and LED displaying. Its advantages are high correctness and reliability and low cost.

The invention discloses an underwater free field pressure sensor. The sensor comprises a sensor body, a first plug is arranged at the top end of the sensor body, a small hole is formed in the front end of the first plug, a hose is arranged in the middle of the sensor body, the hose is in a sealed shape and filled with silicone oil, tourmaline is arranged in the hose, a second plug is arranged at the lower end of the hose, a connecting wire is arranged at the lower end of the tourmaline, an IEPE amplifying circuit is arranged in the second plug, the connecting wire penetrates through the secondplug to be connected with the IEPE amplifying circuit, and an output signal line is arranged at the bottom end of the second plug. The underwater free field pressure sensor provided by the inventionis made of tourmaline piezoelectric crystals, can sense pressure shock waves from any underwater direction, is high in reliability and wide in frequency response, and is suitable for underwater explosion test.

The present invention discloses one kind of adaptive transistor impedance converter. The impedance converter includes single-end input audio power amplifier and features that the single-end input audio power amplifier has one input pulldown inductor connected to ground. The power amplifier made based on the technology of the present invention may be matched freely with electrically driven loudspeaker of 1-16 ohm impedance to produce clear and vigorous high quality sound.