40results about How to "Effective frequency bandwidth" patented technology

The invention relates to a vibrator, in particular to an electric-acoustic transformation acoustic generator with the function of vibration. A magnetic fluid is arranged at the bottom of a bowl-shaped magnetizer. A protruding elastic damping balance is arranged in the corresponding position of the magnetic fluid on a bottom cover. The elastic damping balance and a vibration unit with magnetic fluid are propped against each other in the vibration state, so as to overcome the disadvantage of small damp in a miniature electric-acoustic generator in the related technology, enable the resonance amplitude to be inhibited when the miniature electric-acoustic generator works, increase the voltage to be borne by the miniature electric-acoustic generator and widen the effective frequency band of the miniature electric-acoustic generator. Therefore, the resonance amplitude is inhibited, so that the collision of the inner parts of the acoustic generator can be avoided, and the power to be borne by the invention is increased. Besides, the counterforce is strengthened when the resonance happens, so that the effective frequency band of the electric-acoustic transformation acoustic generator gets wider.

A three-dimensional graphene sponge / Fe2O3 composite wave absorbing material and a preparation method thereof are disclosed and belong to the technical field of wave absorbing materials. Firstly, three-dimensional graphene is prepared through a template process and is then added into deionized water, the mixture is subjected to ultrasonic treatment to obtain a uniformly dispersed three-dimensionalgraphene sponge suspension, then an aqueous Fe<3+> solution is added into the suspension dropwise, and a reaction occurs at 70-95 DEG C after the pH value is adjusted with ammonia water. The structureand wave absorbing performance of the composite wave absorbing material are adjusted through controlling the using amount of FeCl3, the pH value, the reaction temperature and the reaction time. A graphene matrix of the composite wave absorbing material in which the graphene sponge is loaded with magnetic nanometer Fe2O3 particles has a mesoporous sponge structure, and the Fe2O3 particles are uniformly anchored and grow on the graphene sponge. The prepared composite wave absorbing material has characteristics of high wave absorbing intensity, effective absorption frequency bandwidth, low density, low thickness, and the like, and has important application value in the field of developing efficient and light-weight electromagnetic wave absorbing materials.

The invention discloses a novel muffler which not only can block off the transmission of acoustic waves and enable air flows to pass through, but also can eliminate emptying noise of a purification apparatus. Such a muffler is provided with a large amount of tiny pores and is capable of filtering the discharged air flows into countless small air flows, the gas pressure is reduced and the flow speed is diffusely diminished by reflecting partial acoustic waves to an acoustic source direction via an abrupt change location of acoustic characteristics within a pipeline, then secondarily passing the reflected acoustic waves through the pipeline and finally by acoustic absorption of an acoustic absorbing material of a filter at an inlet of a waste air compressor, thus achieving the aim of noise elimination in the end to thereby reduce environmental pollution and noises in industrial boundary. The invention has the advantages of small volume, large noise elimination quantity, small investment, simple structure, convenient installation, small loss of resistance and the like, and is wider in effective frequency band, extensive in application range and best in eliminating the middle / high frequency noises.

According to some aspects of this invention, a compact, broadband active receiving antenna uses one or more high transconductance transistors such as Field Effect Transistor(s) paired with another Transistor and arranged in a Cascode amplifier configuration. Some embodiments involve a single high transconductance transistor arranged with a high efficiency transformer in a nondissipative feedback loop to improve linearity and dynamic range. The devices have a high input resistance, low input capacitance, low noise and a very high second and third order Intercept Point. Since the gain is primarily a function of the amplifying electronics, it is not necessary to increase the directivity of the antenna to achieve higher gain.

The invention relates to a piezoelectric-electromagnetic hybrid fluid energy capture device and belongs to the technical field of power generation. The end portion of a side wall of a housing is provided with an end cover; the inner side of a bottom wall of the housing is embedded with coils, and the outer side is provided with upper and lower ear plates; and guide pillars are arranged between the upper and lower ear plates. A bluff body is formed by a cylinder body, a protrusion and side plates. The side plates of the bluff body are sleeved on the guide pillars and the upper and lower sides are respectively compressed by a pressure spring; and the protrusion of the bluff body is equipped with a magnetic bar. A framework bottom plate provided with ear plates is arranged on the end cover. An exciter comprises upper and lower planes, left and right arc surfaces, a groove, a protrusion, a shaft hole and a pin hole. The groove and the pin hole are arranged in one side of the left arc surface; and the protrusion equipped with a magnetic block is arranged on one side of the right arc surface. The exciter is sleeved on a rotation shaft. The rotation shaft is arranged on the framework ear plates. A long pin is arranged on the framework ear plates. Each of the two ends of a short pin is arranged in the pin hole of exciter. The two ends of a tension spring are connected to the long pin and the short pin respectively. The two sides of the framework bottom plate are respectively provided with an energy transducer. The energy transducer is formed by a substrate and a piezoelectric film, which are glued together. The substrate is arranged close to the framework bottom plate. The free end of each energy transducer is abutted against the upper plane or the lower plane of the exciter.

The invention relates to a pulling and pressing type vibration energy harvester and belongs to the technical field of new energy and power generation. The upper wall of a hanging frame is fixed to a vibration main body through screws, a tension spring is fixed to the upper wall of the hanging frame and is arranged in an inner cavity of the hanging frame in a sleeved mode, the lower end of the tension spring is fixed to a cover plate, and the cover plate makes contact with the end face of the cylindrical wall of the hanging frame. The cover plate is fixed to the end of the cylindrical wall of a shell through screws, and an inertia block is sleeved with the inner cavity of the shell. Two metal sheets with piezoelectric patches bonded to the arc sections of the metal sheets are riveted with each other through rivets to form a piezoelectric vibrator, and the piezoelectric vibrator and supports riveted to the two ends of the piezoelectric vibrator jointly form energy converters. The upper side and the lower side of the inertia block are connected with the supports of the two energy converters through screws respectively, the other support of the energy converter above the inertia block is fixed to the cover plate through screws, and the other support of the energy converter below the inertia block is fixed to the bottom wall of the shell through screws. The pulling and pressing type vibration energy harvester has the advantages of being high in reliability, suitable for vibration environments of low frequency and large amplitude, capable of achieving vibration energy recovery in the longitudinal direction and any horizontal direction and wide in effective frequency band.

The invention relates to a runner-type piezoelectric beam energy harvester with a suspended shaft end, and belongs to the field of piezoelectric power generation. A left end cover and a right end cover are arranged at the left side and the right side of a runner respectively; metal substrates provided with cantilever beams are crimped between the left end cover and the side wall of the runner and the right end cover and the side wall of the runner respectively; each metal cantilever beam and an adhered piezoelectric crystal plate form a piezoelectric vibrator; an excited magnet is arranged at a free end of each piezoelectric vibrator, is arranged close to the runner and is arranged in a rectangular guide groove in the side surface of the runner; a cantilever shaft of a gear is arranged in a center hole of the runner and the end part is connected with the right end cover; the cantilever shaft and a ring cavity in the runner form a slideway; a cylindrical exciter made of a non-ferromagnetic material is arranged in the slideway; and exciting magnets are inlaid into two ends of the exciter. The runner-type piezoelectric beam energy harvester with the suspended shaft end has the features and advantages that a fixed support is not needed, the structure is simple and the rotating force on the exciter is small; the piezoelectric vibrators are reasonable in structure and the stresses of various points are the same after deformation; the piezoelectric vibrators are high in generating capacity, high in reliability and wide in effective band; and the runner-type piezoelectric beam energy harvester can be applied to the occasion of coaxial cantilever shaft gear and multi-gear as a standard component.

The invention relates to a rotary piezoelectric-friction composite generator, which belongs to the technical field of new energy. The end of the flat shaft of the rotating shaft is provided with an inclined shaft, the flat shaft is installed on the bottom of the casing, and the excitation ring with a pull-out groove on the outer edge is set on the inclined shaft; The piezoelectric vibrator is located on both sides of the composite beam, the ring frame ring plate is clamped on the outside of the piezoelectric vibrator, and the guard plate of the ring frame is provided with a sinker; the composite beam is composed of the beam base plate and the friction layer on both sides, and the piezoelectric vibrator is composed of the vibrator The substrate is composed of a piezoelectric sheet bonded to one side, the vibrator substrate is installed close to the friction layer of the composite beam, the piezoelectric sheet is installed close to the ring frame and placed in the sink, and the free end of the composite beam is placed in the pull groove; the vibrator substrate and The piezoelectric sheet constitutes the piezoelectric power generation unit, the vibrator substrate and the composite beam constitute the friction power generation unit, and the excitation ring drives the composite beam to swing axially to make the piezoelectric vibrator bend and deform, and the vibrator substrate and the friction layer alternately contact and separate, and then convert the mechanical energy into electrical energy.

The invention relates to a telescopic pipeline flow generator, which belongs to the technical field of new energy and pipeline monitoring. The inner wall of the pipeline is equipped with a shell through the radial plate, and the end of the side wall of the shell is equipped with an end cover; the left and right sides of the vertical plate of the support are provided with left and right pins, and the right sides of the upper and lower ends are provided with horizontal plates with inclined mounting surfaces; The left pin protrudes through the bottom wall of the shell, and a blunt body is installed at the end of the left pin; a support spring and a buffer spring are respectively set between the bottom wall of the upper shell of the left pin, the blunt body and the vertical plate of the bracket; From left to right, there are left spring, exciter, frequency modulation block and right spring in turn. The exciter is connected to the frequency modulation block. The right end of the right spring is against the stopper at the end of the right pin; A moving cam composed of a bottom surface, a slope and a top surface is provided in the axial direction; one end of the piezoelectric vibrator is installed on the mounting surface of the bracket, and the flange of the piezoelectric vibrator substrate is in contact with the midpoint of the cam slope when it is not working, and the assembly is pre-bent and deformed The amount is half of its allowable value, and the allowable deformation of the piezoelectric vibrator is greater than the cam lift.

The invention relates to a vehicle-mounted apparatus with functions of positioning, tracking and collision warning, and belongs to the electronic technical field of automobiles. Ear plates are arranged on the left and right side walls of upper and lower shells; limiting surfaces are arranged on the end parts of the front and back side walls; an acceleration sensor is arranged on the left side wall or the right side wall of the upper shell; a circuit board with an emission unit is arranged on the bottom wall of the lower shell; the upper and lower ear plates are connected through screws, and a cantilever beam type metal substrate is crimped between the upper and lower ear plates; the metal substrate, and piezoelectric wafers which are pasted on the upper and lower sides of the metal substrate form a piezoelectric vibrator; a moving magnet I and a mass block are arranged on the upper and lower sides at the free end of the metal substrate respectively; a moving magnet II is mounted at the lower end of the mass block; the moving magnet I, the mass block and the moving magnet II form an excitation arm; the width of the inner cavities of the upper and lower shells is less than that of the metal substrate, and greater than that of the piezoelectric wafers; and a fixed magnet I is mounted on the top wall of the upper shell while a fixed magnet II is mounted on the bottom wall of the lower shell. The vehicle-mounted apparatus with the functions of positioning, tracking and collision warning has the advantages and characteristics of high environmental adaptability, wide effective frequency band, high power generation capacity, and high reliability; and meanwhile, the vehicle-mounted apparatus can be used as an independent part to be embedded in a hidden place of the vehicle body, so that the vehicle-mounted apparatus is safe and reliable.

The invention relates to a rolling bearing with a self-monitoring system, and belongs to the technical field of bearings. An outer ring is divided into left and right cavities by an annular separation plate; an inner ring is mounted in the right cavity by a roller; the annular separation plate is provided with a circuit board and a sensor; a shaft table of a cam shaft is sleeved in an inner hole of the inner ring; a shaft shoulder of the cam shaft is mounted on the inner ring; a sealing ring is pressed between the shaft shoulder and the annular separation plate; the cam shaft is provided with a cam groove; a transducer is mounted on a boss on the inner wall of the outer ring, and is formed by bonding a PZT film on a substrate; a poking block with a pin shaft is mounted at a free end of the transducer; a rolling body coats the pin shaft, and is positioned in the cam groove; when the rolling body is contacted with the peak of the cam surface on the right side of the cam groove, the transducer cannot be bent to deform; when the rolling body is contacted with the peak of the cam surface on the left side of the cam groove, the maximum stress on the PZT film is smaller than an allowed value, and the deformation on a compound layer of two laminated pieces at the free end of the transducer is smaller than an allowed value; and the transducer and the sensor are connected with the circuit board by different lead sets.

The invention relates to a piezoelectric generator for a train wheel train monitoring system, which belongs to the technical field of new energy sources. The frame is equipped with a shell and a wheel shaft with a turntable, and the main magnets are evenly distributed on the turntable; there is a mounting surface on the side wall of the frame, and the two ends of the pin shaft are respectively fixed on the upper and lower walls of the shell, and the pin shaft is covered with a support spring. , exciter and buffer spring, the exciter press-connects the buffer spring and the support spring to the upper wall and the lower wall of the shell respectively; the exciter is provided with a set of cams and bosses, and the bosses are equipped with secondary magnets, the main magnet and the The auxiliary magnet constitutes the magnetic pair, and the cam surface is composed of the bottom surface, the inclined surface and the top surface connected in sequence; the piezoelectric vibrator with the substrate flanging at the free end is installed on the mounting surface of the frame, and the piezoelectric vibrator is composed of a substrate of equal thickness and a piezoelectric vibrator. The flange of the substrate is pressed against the cam surface; when the piezoelectric vibrator is not in operation, the pre-bending deformation generated by the installation of the piezoelectric vibrator is half of its allowable value; when the support spring and the buffer spring are pressed to death, the flange of the substrate Keep in contact with the top and bottom faces of the cam, respectively.

The invention provides a method and a device for removing ghost reflection interference. The method comprises the steps of acquiring seismic data of each detection point in the frequency domain; acquiring the distance between each detection point and a seismic focus and the distance between the seal level to a sub-bottom reflection interface, and determining an offset factor reflecting the offset of each detection point according to the distances; determining the delay time of ghost reflection of each detection point according to a preset calculation method for the ghost reflection delay time on the basis of the offset factor; determining an operator for removing the ghost reflection of each detection point according to a preset calculation method for removing the ghost reflection on the basis of the delay time; and determining a frequency domain value of the seismic data with the ghost reflection interference being removed of each detection point according to the seismic data and the operator. In the embodiment of the invention, not only a low-frequency component of the seismic data in the frequency domain is recovered, and a high-frequency component of the seismic data is also recovered, so that the effective frequency band is effective expanded, the resolution and the signal-to-noise ratio of the seismic data are improved, and the noise interference of seal level ghost reflection multiple waves can be effectively removed.

The invention relates to a ship-borne positioning device, and belongs to the field of ship electronic technologies. An upper cover is installed at an end part of a main board, a circuit board with an emission unit is installed at end parts of bosses of the upper cover, and L-shaped metal substrates are installed on side walls of the bosses; a piezoelectric vibrator is formed by a main beam of the metal substrate and piezoelectric wafers spliced with the main beam, and a first exciter is formed by a secondary beam of the metal substrate, and a first mass block and a first magnet which are installed on the secondary beam; four sink troughs are symmetrically arranged at the upper end of a main body, and a cavity is arranged at the lower end of the main body; limit surfaces are arranged on side walls between each two adjacent sink troughs, a swing rod is welded with the center of the bottom wall of the main body, a second exciter is formed by the swing rod, and a first spring, a second mass block with a second magnet, a second spring, a third mass block, and a third spring which are sequentially sleeved on the swing rod from the top down, and like magnetic poles of the first and second magnets are installed close to each other; a coil is installed on the bottom wall of the main body, and the coil is placed below the first or second magnet. The ship-borne positioning devices has the advantages and characteristics of being strong in environmental adaptability, wide in effective band and large in capacity density, being capable of serving as an independent component to be embedded into a secret place of a ship body, and being safe and reliable.

A three-dimensional graphene sponge / Fe2O3 composite wave absorbing material and a preparation method thereof are disclosed and belong to the technical field of wave absorbing materials. Firstly, three-dimensional graphene is prepared through a template process and is then added into deionized water, the mixture is subjected to ultrasonic treatment to obtain a uniformly dispersed three-dimensionalgraphene sponge suspension, then an aqueous Fe<3+> solution is added into the suspension dropwise, and a reaction occurs at 70-95 DEG C after the pH value is adjusted with ammonia water. The structureand wave absorbing performance of the composite wave absorbing material are adjusted through controlling the using amount of FeCl3, the pH value, the reaction temperature and the reaction time. A graphene matrix of the composite wave absorbing material in which the graphene sponge is loaded with magnetic nanometer Fe2O3 particles has a mesoporous sponge structure, and the Fe2O3 particles are uniformly anchored and grow on the graphene sponge. The prepared composite wave absorbing material has characteristics of high wave absorbing intensity, effective absorption frequency bandwidth, low density, low thickness, and the like, and has important application value in the field of developing efficient and light-weight electromagnetic wave absorbing materials.

The invention relates to a rotationally excited friction-piezoelectric composite generator, which belongs to the technical field of new energy sources. The end cover is installed at the end of the cylinder, and the rotating shaft is installed on the end cover and the bottom of the shell; the swing ring of the exciter is set on the fixed ring, and there is an axial inclination between the fixed ring and the axis of the swing ring, and a dial ring is arranged on the outer edge of the swing ring. Both sides of the ring are equipped with paddles, the fixed ring is installed on the rotating shaft and rotates with the rotating shaft; the two brackets and the spacer ring are installed on the inner side of the shell, the bracket is composed of a ring plate and a guard plate, and the convex surface of the guard plate is provided with Composite film composed of friction layer and electrode layer; a piezoelectric vibrator is crimped between the ring plate of the bracket and the spacer ring, the substrate of the piezoelectric vibrator is installed close to the friction layer, and the piezoelectric vibrator and the composite film constitute a friction pair; The paddle on the side is located between two axially adjacent piezoelectric vibrators; when the shaft rotates, the paddle forces the piezoelectric vibrator to reciprocally bend and deform, and repeatedly contacts and separates from the composite film, the substrate of the piezoelectric vibrator and the piezoelectric vibrator The piezoelectric power generation end is formed between the sheets, and the friction power generation end is formed between the substrate and the composite film.

The invention relates to a suspension self-excitation runner piezoelectric beam energy harvester and belongs to the field of piezoelectric power generation. A left end cap, a disc body, a side plate and a right end cap are sequentially connected and are arranged on a cantilevered shaft in a sleeving mode. A cantilever beam of a metal substrate and a bonded piezoelectric crystal plate between the left end cap and the disc body form a piezoelectric vibrator, and a cantilever beam of a metal substrate and a bonded piezoelectric crystal plate between the side plate and the right end cap form a piezoelectric vibrator. The piezoelectric vibrators are provided with excited magnetics. An exciter is mounted in a slideway form by the cantilevered shaft and an annular cavity of the disc body. Balls are embedded in the inner edge and the outer edge of the exciter, and exciting magnets are embedded in the two sides of the exciter. The piezoelectric vibrators on the two sides of the exciter are equal in number and are symmetrically mounted. The side of the left end cap, the side of the disc body, the side of the side plate and the side of the right end cap which are adjacent to the piezoelectric vibrators are provided with limiting faces and sink grooves which are identical in shape, size and number. The suspension self-excitation runner piezoelectric beam energy harvester has the advantages and characteristics that fixing and supporting are not needed, structure is simple, and rotation force to the exciter is small; the piezoelectric vibrators are reasonable in structure and equal in stress of points after deformation, the power generation amount is large, the reliability is high, and effective frequency band is wide; and the suspension self-excitation runner piezoelectric beam energy harvester can be used as a standardized part to be applied to cantilevered shaft gears and the multi-gear coaxial occasions.

The invention relates to a constant-amplitude excitation turbine piezoelectric-friction generator, which belongs to the technical field of new energy sources. The end cover is installed on the end of the casing, the rotating shaft is installed on the end cover and the bottom of the casing, and the circuit board is installed on the bottom of the casing: the shaft sleeve with the excitation ring on the outer edge is sleeved on the rotation shaft, and the axis of the excitation ring is in line with the casing. The cylinder axis is parallel; the excitation ring is set on the excitation ring, and there are inclined excitation surfaces on both sides of the outer edge of the excitation ring; The electric sheet and the substrate are composed of a radial beam on the inner edge of the spacer ring of the spacer, and a composite film composed of a friction layer and an electrode layer is bonded on both sides of the radial beam; the substrate and the piezoelectric sheet constitute a piezoelectric power generation unit, and the substrate and The composite film adjacent to it constitutes a triboelectric power generation unit; when the piezoelectric vibrator is in no deformation, the side of the substrate is attached to the friction layer adjacent to it, and the free end is in contact with the excitation surface; the piezoelectric power generation unit and the triboelectric power generation unit are different The wire set and rectifier bridge are connected to the circuit board.

The present invention relates to a water flow-induced vibration energy accumulator and belongs to the technical field of electric power generation. An end part of a side wall of a shell body is provided with an end cap, a wire coil is embedded inside a bottom wall, upper and lower ear plates are arranged on an outer side of the bottom wall, and a long pin is fixed on the upper and lower ear plates; a flow disturbing body consists of a column body, a boss and a side plate; the side plate sleeves the long pin, and two pressure springs sleeving the long pin are pressed on upper and lower sides of the side plate; a magnetic strip is mounted on the boss, the magnetic strip is installed near a bottom wall of the shell body; a frame is provided with a frame bottom plate as well as inner and outer ears plates, the bottom plate of the frame is mounted on the end cap, a rocker arm of an exciter is provided with a rocker ear plate and a cam, a magnetic block is mounted on the rocker arm, the rocker arm sleeves a rotary shaft, two ends of the rotary shaft are fixed on the outer ear plate, pin shafts are mounted on the inner ear plate and the ear plate of the rocker arm, two ends of a tension spring are connected onto the pin shaft, energy transducers are mounted on an upper side and a lower side the frame bottom plate, each energy transducer is formed by bonding a substrate and a piezoelectric membrane, end parts of the energy transducers are butted against a vertex of the cam, a cam contour curve comprises two arc contours that are concentric with an axle hole, and the energy transducers are of a flat and straight structure before installation.

The invention discloses a Vivaldi antenna for near-field imaging of 30-40GHZ millimeter waves, and relates to the field of communication technology. The antenna reduces the number of upper and lower exponential curve sides within 30-40GHZ by redesigning the shape of the exponential curve side The energy of the electromagnetic field dissipates, and then increases the gain in this frequency band, reduces the side lobe, and the effective frequency band between 30-40GHZ is wider; the shape of the gap is redesigned, which can make the direction of some messy currents in the tail wing and the main The radiation direction is consistent, reducing stray currents and increasing the gain; adding a director, and then further reducing the electric field different from the main radiation direction, enhancing the electromagnetic field in the main radiation direction, suppressing the cross-polarization phenomenon more obviously, and increasing the gain effect.

The invention relates to a telescopic pipeline flow energy harvester, which belongs to the technical field of new energy and pipeline monitoring. The pipe is equipped with a shell, and the end of the side wall of the shell is equipped with an end cover; the center of the vertical plate of the bracket is provided with an inner pin hole, and the upper and lower ends of the same side of the vertical plate are provided with horizontal plates with inclined mounting surfaces; the left and right sides of the exciter There are left and right pins on the sides, and multiple cams are provided on the upper and lower sides along the axial direction of the left and right pins. The cam surface is composed of a bottom surface, an inclined surface and a top surface connected in sequence; the actuator is placed in the shell and the left pin passes through the bottom wall of the shell. The end of the left pin is equipped with a blunt body; the left pin on the left and right sides of the bottom wall of the shell is respectively covered with a support spring and a buffer spring; the vertical plate of the bracket is installed on the right pin through the inner pin hole, and the left and right sides of the vertical The right pin is respectively covered with a left spring and a right spring; one end of the piezoelectric vibrator is installed on the mounting surface of the bracket, and the piezoelectric vibrator is a cantilever beam structure bonded by a substrate and a piezoelectric sheet. It leans against the cam surface, and the top block is in contact with the midpoint of the inclined surface of the cam when it is not working.

The invention discloses a grounding piezoelectric ceramic charge driver with a composite low-frequency channel, and relates to a charge driver. The charge driver aims at solving the problems of poor low-frequency characteristic and poor universality of the existing charge controller. Non-inverting input ends of an operational amplifier A3 and an operational amplifier A4 are connected and serve as an input end of the driver; an output end of the operational amplifier A4 is connected with an inverting input end of the operational amplifier A3 by an adjustable gain K2; an output end of the operational amplifier A3 is connected with a non-inverting input end of a high-voltage operational amplifier A1 and an input end of a fixed gain K; an output end of the high-voltage operational amplifier A1 is connected with one end of a sensing capacitor C1 and an inverting input end of an operational amplifier A2; an output end of the operational amplifier A2 is connected with an inverting input end of the high-voltage operational amplifier A1; the other end of the sensing capacitor C1 is connected with a non-inverting input end of the operational amplifier A2, connected with an inverting input end of the operational amplifier A4 by a fixed gain K1, and connected with an output end of the fixed gain K by an adjustable resistor R; and the other end of piezoelectric ceramic Cp is grounded. The charge driver is used for driving the piezoelectric ceramic.