85results about How to "Improve electro-acoustic conversion efficiency" patented technology

The invention relates to a digital loudspeaker drive method and a device based on quaternary code dynamic mismatch reshaping. The method comprises the steps of (1) conducting input format conversion, (2) conducting multi-bit sigma to delta modulation, (3) conducting thermometer code conversion, (4) conducting dynamic mismatch reshaping processing, (5) conducting channel data combination and mapping coding, (6) controlling metal-oxide-semiconductor field effect transistor (MOSFET) pipe of a full-bridge power amplifier network to conduct opening and closing status switching, and driving a digitalized loudspeaker load to produce sound. The device comprises a sound source (1), a digital format converter (2), a multi-bit sigma to delta modulator (3), a thermometer coder (4), a dynamic mismatch reshaper (5), a channel data combiner (6), a mapping coder (7), a multi-channel digital amplifier (8) and the digitalized loudspeaker load (9). The units are sequentially connected in order. According to the digital loudspeaker drive method and the device based on quaternary code dynamic mismatch reshaping, use efficiency of an amplifier pipe and the load is improved, development periods and hardware implementation cost are saved, and good immunity is provided for frequency response deviation of digital channels.

The invention discloses a sound production structure unit and an earphone including the sound production structure unit, and relates to the technical field of sound production devices. The sound production structure unit comprises a diaphragm and a piezoelectric ceramic, wherein the piezoelectric ceramic is used for generating mechanical deformation under excitation of driving signals of a drive circuit so as to drive the diaphragm to vibrate and produce sound. The invention further provides an earphone utilizing the sound production structure unit. The sound production structure unit provided by the invention combines a transmission structure of a moving iron earphone and materials of the piezoelectric ceramic, which retains the advantages and avoids the deficiencies; the structure is simple and compact; the diaphragm and the piezoelectric ceramic are separately arranged, so that the electric-acoustic conversion efficiency is high, and the tone quality is excellent; furthermore, a design space is provided for adjusting a vibration mode of the diaphragm and optimizing the tone quality.

The invention discloses a medical ultrasonic surgical knife. The medical ultrasonic surgical knife comprises a knife bar, wherein the knife bar is provided with a connecting end, a knife point and a periodic repeating structure positioned between the knife point and the connecting end; the periodic repeating structure consists of rough structures and fine structures which are arranged alternatively; all the rough structures are the same in masses; all the fine structures are the same in masses; the distance between the gravity centers of any two adjacent rough structures differs from the distance between the gravity centers of any other two adjacent rough structures by 0.3 millimeter. When sound wave pass through the periodic repeating structures, vibration is transmitted forwards to the periodic repeating structures from a threaded segment and a connecting segment, the frequency is selected by the structures, responses are made to sound waves of required frequencies, sound waves are transmitted to a knife head in a resonant form, and sound waves of unrequired frequencies are cut off and are prevented from being transmitted to the knife head. Thus, the ultrasonic surgical knife can work at a stable frequency, and difficulty in surgical operation and non-safety are not increased due to frequency drifting.

The invention discloses electronic display equipment and electronic equipment. The electronic display equipment comprises a shell, a screen and a vibration device; at least a part of the screen is connected with at least a part of the shell through a flexible connection device; the flexible connection device has elastic, the vibration device is fixed on the screen, the vibration device is configured to produce vibration in response to an electric signal of the external circuit, and drive the screen to make sound by vibration. In the electronic display equipment disclosed by the embodiment of the invention, the screen and the shell are connected through the flexible connection device but not in fixed connection; the screen cannot drive the shell to vibrate together in the vibration, therebyeffectively reducing the sound leaking caused by the vibration of the shell.

The invention relates to a speaker, in particular to a flat panel speaker which ensures electric energy is converted to sound energy. The flat panel speaker comprises a diaphragm, a frame and a driver system; the diaphragm is characterized by the flexibility and is stretched by a pretightening force along at least one direction, and then is fixed on the frame and coupled with a drive system, and vibrates to sound after being excited by the drive system. The drive system at least comprises a power amplifier and an executor. The executor can directly connected to the back surface of the diaphragm to excite the diaphragm to sound, and the change of fluid pressures in a cavity at the back of the diaphragm can also be controlled to indirectly excite the diaphragm to vibrate and sound. Output sound pressure and frequency response of the speaker can be modulated by changing the pretightening force and peripheral constraint of the diaphragm; the pretightening force of the diaphragm is improved to enhance the intermediate frequency and high frequency responses of the speaker, reduce the peripheral constraint of the diaphragm and enhance the low frequency response of the speaker.

The invention discloses a loudspeaker diaphragm, a loudspeaker and a mobile terminal. The loudspeaker diaphragm comprises a cone which is provided with a coaxial spacing part at an inner wall, and a piezoelectric ceramics sheet which is in axial fixation with the cone through the coaxial spacing part. An external diameter of the piezoelectric ceramics sheet is less than an internal diameter of the cone, and resonance frequency of the cone is lower than resonance frequency of the piezoelectric ceramics sheet. According to the invention, tone quality of a single loudspeaker is improved, and high electroacoustic conversion efficiency of the loudspeaker is obtained simultaneously.

The invention discloses an electronic display device and an electronic device. The electronic display device comprises a casing, a screen and a vibration device, wherein at least a part of the screenis connected to at least a part of the casing through a flexible connecting device, at least one of the screen and the casing is provided with a receiving groove for fixing the flexible connecting device, the flexible connecting device is elastic, the vibration device is fixed on the screen, and the vibration device is configured to vibrate in response to electrical signals of an external circuitand drive the screen to vibrate and sound. The screen is connected with the casing by the flexible device instead of a fixed connection, and the casing does not vibrate when the screen vibrates, thereby effectively reducing the sound leakage caused by the vibration of the casing. The connection strength of the flexible connecting device to the casing and the screen is improved by the flexible connecting device receiving groove.

The invention relates to a portable ultrasonic physiotherapy instrument based on a fuzzy control algorithm. The portable ultrasonic physiotherapy instrument mainly comprises a drive module, a system control module, a circuit protecting module, a wireless transmission module, an ultrasonic transducer, an oscillator and a frequency tracking circuit and is characterized in that the fuzzy control algorithm is mainly used to control the functional modules of the physiotherapy instrument, and the ultrasonic transducer adopting a impedance matching design allows acoustical power to be stably output to achieve feedback type treatment; the physiotherapy instrument can efficiently and stably output ultrasonic waves to effective treat human body lesions, and an ultrasonic effect can be shown favorably; the phase difference signal of voltage and currents at two ends of the transducer is obtained and input into a fuzzy controller to regulate PWM waveform frequency in real time, and accordingly theultrasonic transducer constantly work at resonant frequency to achieve frequency tracking; the wireless transmission module transmits related data to a mobile phone terminal to perform corresponding control.

The invention discloses an online impedance measuring and dynamic matching system for an ultrasonic transducer, and belongs to the technical field of impedance matching of the ultrasonic transducer. In order to overcome the problems of high matching cost, poor success rate and low electro-acoustic conversion efficiency in the prior art, the online impedance measuring and dynamic matching system for the ultrasonic transducer provided by the invention comprises a signal generator and the ultrasonic transducer; an impedance measuring system, an impedance matching circuit, a single chip microcomputer system and a driving module are disposed between the signal generator and the ultrasonic transducer; the impedance measuring system comprises a current probe, a voltage probe and a computer controlled collection system connected with the current prove and the voltage probe; the computer controlled collection system is connected with the single chip microcomputer system; the single chip microcomputer system is connected with the driving module; and the driving module is connected with the impedance matching circuit. According to the online impedance measuring and dynamic matching system provided by the invention, the impedance measuring and real-time matching can be performed on an ultrasonic transducer in a working state, and thus the electro-acoustic conversion efficiency of the ultrasonic transducer is improved.

The invention belongs to the field of loudspeaker technology and manufacture and relates to a multipurpose bidirectional horn loudspeaker. The loudspeaker comprises a front horn and a rear horn that are driven by a driving unit; the front horn is connected with a front larynx cover and a front larynx plug of the driving unit; the rear part of the front larynx plug is provided with a front chamberthat is connected with a vibration film; the vibration film is connected with a voice coil paper tape; the rear horn is connected with a rear larynx cover and an internal rear larynx plug in the driving unit; the rear part of the rear larynx plug is provided with a rear chamber; the position between the front and the rear larynx plugs, namely, the center of the driving unit, is provided with a magnetic circuit system and a vibration system; and a front radiating horn and a rear radiating horn commonly use one magnetic circuit system and one vibration system. The loudspeaker has the beneficialeffects that the electro-acoustic conversion efficiency of the loudspeaker is improved greatly, the energy-saving and material-saving effect is outstanding, the heating condition of the driving unit is greatly improved, therefore, the damage possibility of the key part voice coil affecting the reliability of the loudspeaker is reduced, the service life of the loudspeaker is prolonged, the using cost is reduced, the usage is convenient and a large amount of electric energy and raw material resources are saved.

The invention relates to an impulse discharge electrode, which comprises a high-voltage electrode (1), a low-voltage electrode (2), an insulated sleeve (3), and a reflector (4). Wherein, said four parts both use coaxial structures; the high-voltage electrode (1) is a round rod, whose outer part is mounted with an insulated sleeve; the high-voltage electrode (1) and the insulated sleeve are connected by screw or fixed together; the outer left section of insulated sleeve is sheathed with a tube low-voltage electrode (2) while the right section is sheathed with a cylinder reflector (4) with central hole; the insulated sleeves have outer screws; the low-voltage electrode (2) and the central hole of cylinder reflector (4) have inner screws; the left end surface of cylinder reflector (4) is a inward concave semi-ellipsoid; the cylinder reflector (4) is connected to the insulated sleeve; the end of high-voltage electrode (1) is at the focus of semi-ellipsoid. The invention has simple structure, better discharge stability and repeated property, with long service life and high electric sound transform efficiency.

The invention relates to a loudspeaker, in particular to a three-dimensional wave coaxial motor-driven loudspeaker. The three-dimensional wave coaxial motor-driven loudspeaker comprises a voice coil set, vibrating diaphragms, a cylinder, a cone support, a locating support and a spiral rubber pipe wire. The three-dimensional coaxial motor-driven loudspeaker is characterized in that the voice coil set is formed by m voice coils in same structure, the m vibrating diaphragms are same in structure, the m vibrating diaphragms and the voice coil set are coaxial and synchronous, and the m vibrating diaphragms are coaxial with the sound basin support; the cylinder is jointly and coaxially formed by a screw, n magnets, m separating sheets or I-shaped sleeves and nuts; the cylinder is respectively fixed on the sound basin support and the locating support, and the sound basin support, the locating support and the cylinder are concentric and coaxial with the vibrating diaphragms; a voice coil set lead is the spiral rubber pipe wire; the n is larger than or equal to three, and the m is larger than or equal to two. The three-dimensional coaxial motor-driven loudspeaker has the advantages of being high in sensitivity, high in fidelity factor, high in electricity-sound conversion efficiency and low in requirement for power amplification. Frequency response fidelity at 20 Hz-20 KHz is guaranteed, and the convention that the loudspeaker is not used in a music hall will be broken.

An integrated digital vehicle sound equipment system is disclosed. Vehicle sound equipment is arranged behind a headrest assembly of a rear-row seat, and the front side of the sound equipment is at a 0-90-degree included angle to the horizontal plane. The vehicle sound equipment is provided with a bar-shaped housing with a semi-elliptic cross section. The housing is divided into a left sound box and a right sound box, which are symmetric, through a baffle plate, and a digital audio control system is arranged in the housing. The integrated digital vehicle sound equipment system has the advantages of small size, small occupied area, lossless installation, dismounting convenience, easy operation, flexible application and high fidelity sound quality.

The invention discloses an agriculture electric agricultural chemical spraying device capable of enabling convenient mixing of agricultural chemicals. The invention relates to a jellyfish driving infrasonic wave acoustic generator which is technically characterized in that an electric driver suspending support is fixedly mounted at a center of a bottom part of a water resistant and a pressure resistant cavity, a heat exchanger is mounted outside the electric driver, a vibrating wire coil is mounted at the middle of a magnetic gap of the electric driver, the vibrating wire coil is adhered to a water resistant vibrating diaphragm and a damper, the water resistant vibrating diaphragm and a water resistant folding ring are connected in a seamless manner and are fixedly mounted on a driver basin rack, the driver basin rack and the water resistant and a pressure resistant cavity are fixedly mounted together, a watertight pressing ring is mounted on an edge of the water resistant folding ring, a waterproof biological film is attached on the water resistant vibrating diaphragm and the water resistant folding ring, and the water resistant vibrating diaphragm and the water resistant folding ring are protected via installation of an anti-filing net in a notch of the watertight pressing ring.

The invention relates to a general rotating ultrasonic transducer assembly of a high-speed motorized spindle. In most of the prior art, a current collector carbon brush structure or electromagnetic induction is adopted for supplying power to a transducer, and with the same power, the transducer is excessively large in size and low in efficiency and can not operate at a high speed. The general rotating ultrasonic transducer assembly comprises a connecting shaft, a transducer shell, a magnetic resonance transmitter static unit, a magnetic resonance receiver rotating unit and integrated ultrasonic transducer, wherein the connecting shaft and the transducer shell are of an integrated structure, the magnetic resonance transmitter static unit and the magnetic resonance receiver rotating unit are coaxially fixed to the connecting shaft, and the integrated ultrasonic transducer is coaxially fixed in the transducer shell. The transducer comprises an upper cover plate, a piezoelectric element, a lower cover plate of an integrated structure, an amplitude transformer and a cutting tool chuck. According to the technical scheme, a magnetic resonance transmitter in the magnetic resonance transmission state has the recognition characteristic and will not transmit energy to the peripheral metal shell to cause heating, and the transmission efficiency and the reliability are improved; the distance between the rotary unit and the static unit can be freely set within the range of several millimeters, and therefore the assembly difficulty of a whole machine is lowered.

The invention relates to an ultrasonic billiards-ball cleaning method, comprising three main steps of cleaning, rinsing and airing with ionic wind, wherein in each step, revolution is carried out with preset radius and rotation speed, around a rotation central shaft so as to match the billiards-balls for eliminating blind spots and cleaning completely. A special cleaning solution and a special rinsing solution are matched in the steps of cleaning and rinsing. The invention relates to a set of ultrasonic billiards-ball cleaning device in the embodiment of the method. The device mainly comprises a ball delivery system, a cleaning tank, an ultrasonic generating system, a cleaning solution injecting and recycling system, a rinsing solution injecting and recycling system, an ionic wind generation system and a central control system. The method and the device in the invention are more complete on cleaning the billiards balls and all-pervasive on microcosmic pin holes and cleaning blind spots of pits, and can be used for completely clearing special dirt and chalk on the balls, therefore, the balls are integrally consistent in cleanness, static electricity is cleared more completely, and moreover, the invention has the advantages of safer operation, higher working efficiency, energy saving and environmental protection.

The invention discloses a double-voice-coil loudspeaking assembly. The double-voice-coil loudspeaking assembly comprises two loudspeaking single bodies, each loudspeaking single body comprises a magnetic circuit system, a diaphragm and a voice call, the voice coil is connected with the diaphragm, the voice coil is contained in a magnetic gap of the magnetic circuit system, and openings of the magnetic gaps of the two magnetic circuit systems are arranged in an opposite manner. The invention also provides a loudspeaking apparatus with the double-voice-coil loudspeaking assembly. Based on the above scheme, according to the double-voice-coil loudspeaking assembly and the loudspeaking apparatus, high sound pressure level can be provided, and the loudspeaking loudness can be increased.

The invention relates to a full-digitalized super-directivity speaker system based on multi-bit sigma-delta modulation. The system comprises a sound source, a digital input interface, a carrier wave modulator, an interpolation filter, a sigma-delta modulator, a thermometer encoder, a dynamic mismatch reshaper, a multi-channel digital amplifier and an ultrasonic transducer array. The system can achieve full digitalization of a system signal transmission link, highly integrated design can be carried out conveniently, system size and power consumption are reduced, system manufacturing complexity and cost are lowered, system electro-acoustic conversion efficiency is improved, and the system has low electromagnetic radiation level and good antijamming capability at the same time, can well lower the harmonic distortion level for demodulating a sound source signal, and greatly improve articulation clearness of conveyed information and acoustic level. The system has a good sound field control ability, provides a good realization method for voice private conveying, and can better meet development requirements of digitalization and networking at the same time.

The audio equipment comprises a loudspeaker, two input terminals and a control module, the loudspeaker comprises a magnetic circuit system and a vibration system, one end of a voice coil of the vibration system is connected with a vibrating diaphragm, the other end of the voice coil of the vibration system is inserted into a magnetic gap of the magnetic circuit system, the voice coil comprises two voice coil wires, and the two voice coil wires are arranged in the magnetic circuit system. The two voice coil wires are respectively provided with a first coil section and a second coil section, the first coil sections and the second coil sections are sequentially arranged in the axial direction of the magnetic gap, the current direction in the first coil sections is opposite to the current direction in the second coil sections, and the two input terminals are electrically connected with the two voice coil wires respectively and used for inputting current to the voice coil. The control module is electrically connected with the two input terminals, and the control module is used for controlling the two input terminals to switch the connection state and / or the current magnitude of the two voice coil wires. The invention aims to provide the audio equipment capable of eliminating the reverse electromotive force of the voice coil, and the audio equipment can effectively reduce distortion, improve loudness and improve subjective audition quality.

The invention relates to an MEMS ultrasonic transducer technology, and in particular to an MEMS piezoelectric ultrasonic transducer with a horn structure. The transducer comprises an MEMS piezoelectric ultrasonic transducer and a horn-shaped silicon structure, wherein the horn-shaped silicon structure is bonded on the upper surface or the lower surface of the MEMS piezoelectric ultrasonic transducer. A cavity in the horn-shaped silicon structure forms at least one sound wave guide pipe. Each sound wave guide pipe comprises at least two steps. Each step comprises a step sound pipe. The sectional area of each step sound pipe is gradually increased to form a horn-shaped cavity. Each horn-shaped cavity can amplify sound waves generated by the MEMS piezoelectric ultrasonic transducer. In addition, sound waves generated by the back of the MEMS piezoelectric ultrasonic transducer can be conducted to the top of the MEMS piezoelectric ultrasonic transducer and are overlapped with sound waves generated by the top of the MEMS piezoelectric ultrasonic transducer for transmission, so that the intensity of the sound waves generated by the ultrasonic transducer is further improved. According to the device, the intensity of the sound waves generated by the MEMS ultrasonic transducer can be enhanced, and the energy conversion efficiency of the MEMS piezoelectric ultrasonic transducer is improved.

The invention discloses a double-layer piezoelectric ceramic electroacoustic component, comprising two piezoelectric ceramic sheets; the electrode of a first surface of the piezoelectric ceramic sheetcomprises a large electrode region and an island electrode region which are not communicated to each other; a through hole is respectively formed in the large electrode region and the island electrode region; the electrode pattern on the second surface of the piezoelectric ceramic sheet is obtained by rotating the electrode pattern of the first surface by 180 degrees; the polarization direction of the piezoelectric ceramic sheet is directed from the first surface to the second surface; the second surface of the first piezoelectric ceramic sheet is bonded to the first surface of the second piezoelectric ceramic sheet, wherein the island electrode regions are overlapped but the through holes on the island electrode regions do not correspond, and four blind holes are formed after bonding; the four blind holes on the bonded piezoelectric ceramic sheets are filled with a conductive material, the two island electrode regions are respectively connected, and the two large electrode regions are connected. The invention also discloses a preparation method of the double-layer piezoelectric ceramic electroacoustic component. According to the double-layer piezoelectric ceramic electroacousticcomponent and the preparation method thereof in the invention, an intermediate metal layer is not needed to be adopted; the electro-acoustic conversion efficiency is improved, installation and use arefacilitated, and the breakage rate during production is low.

The invention relates to a single-cavity sandwich-type automobile subwoofer. The subwoofer comprises a bass box body, woofers and bass radiator groups, wherein the woofers and the bass radiator groupsare installed in the bass box body. There is at least one woofer and the woofer is installed on the box wall of the bass box body. There is at least one bass radiator group and each group comprises two bass radiator units. The two bass radiator units are arranged correspondingly in front and back portions and are installed on the box wall of the bass box body. The installation plane of the two bass radiator units is coplanar, parallel, vertical or tilted to the installation plane of the woofer. In the invention, through the interaction of the woofer and the bass radiator group, electroacoustic conversion is completed in a single bass box body so that the size of the subwoofer is reduced by 90%; and the weight is light, the shocking, heavy, elastic and pure bass can be generated so that problems that the subwoofer is large and is not easy to install are solved. The subwoofer of the invention is suitable for internal installation of front installation, rear installation and the like ofan automobile, wherein the internal installation has requirements of the small size, thin installation and good bass.

The invention discloses an ultrasonic transducer which comprises a front cover plate, a back cover plate and a prestressed bolt. A piezoelectric ceramic piece and a conductive pole piece are arrangedbetween the front cover plate and the back cover plate; a first inner screw hole is formed in the back end surface of the front cover plate; through holes are formed in the back cover plate, the piezoelectric ceramic piece and the conductive pole piece; a screw rod of the prestressed bolt penetrates through the through holes so as to be fixedly connected with the first inner screw hole of the front cover plate; the front cover plate outwards extend to form a flange structure along the radial direction from the periphery of the front cover plate; a circumferential inner wall surface is arrangedon the flange structure; a flange inner screw thread is arranged on the circumferential inner wall surface; and a spring washer is arranged between the back end surface of the back cover plate and ascrew cap of the prestressed bolt. Compared with an existing design, the ultrasonic transducer has the advantages of simple structure, easiness in implementation, low implementation cost, uniformity in internal stress, high electro-acoustic conversion efficiency, long service life, simple structure, flexibility, good stability, less outward transmission vibration, high performance stability and the like which are not possessed by existing similar products.

The invention provides a double-stimulus two-dimensional longitudinal coupled oscillation sandwich type piezoelectric ultrasonic transducer. The double-stimulus two-dimensional longitudinal coupled oscillation sandwich type piezoelectric ultrasonic transducer comprises a piezoelectric ceramic crystal stack, an outer metal block and a share center coupled metal block, wherein the piezoelectric ceramic crystal stack, the outer metal block and the share center coupled metal block are sequentially and coaxially connected, and a cross-shaped structure is formed by the piezoelectric ceramic crystalstack, the outer metal block and the share center coupled metal block in a horizontal direction and a vertical direction together. According to the double-stimulus two-dimensional longitudinal coupledoscillation sandwich type piezoelectric ultrasonic transducer provided by the invention, defects of lower power capacity, unidirectional ultrasonic irradiation and smaller ultrasonic irradiation areaexisting in a longitudinal oscillation sandwich type piezoelectric ultrasonic transducer in the prior art can be solved to a large extent, and meanwhile, the double-stimulus two-dimensional longitudinal coupled oscillation sandwich type piezoelectric ultrasonic transducer has the advantages of double frequency, two-dimensional four-directional ultrasonic irradiation and the like.

The invention belongs to the technical field of oil production, and particularly relates to an ultrasonic variable-frequency blockage removing, oil outlet increasing and injection increasing device. The ultrasonic variable-frequency blockage removing, oil outlet increasing and injection increasing device comprises a cable, a cable connecting body, a protection cylinder, piezoelectric ceramic and a pressure balance rubber cylinder and further comprises a sealing piston. The cable is connected to the upper side of the cable connecting body through a cable connector assembly. The protection cylinder is fixedly connected to the outer side of the lower end of the cable connecting body. The piezoelectric ceramic is pre-tightened and fixed to the inner side of the protection cylinder through a gland, and copper skin is attached to the inner wall of the piezoelectric ceramic and connected with the cable through a wire and the cable connector assembly, so that power supply is achieved. A wire passing pipe is mounted in the center of the lower end of the cable connector body. The wire penetrates through the center of the wire passing pipe and a wire passing hole in the pipe wall of the wire passing pipe. The sealing piston is mounted in a piston sleeve and can slide in the piston sleeve, and the piston sleeve is connected to the lower end of the protection cylinder through a middle connecting body. The pressure balance rubber cylinder is of a cylindrical structure with the two ends being open.

The invention relates to an ultrasonic wave radiator, comprising radiating rod with transducer at one end or two ends. Several ring grooves are set on the radiating rod. Said ring grooves comprise two faced ring radiating faces. When the rod generates vibration under the excitation of transducer these radiating faces can radiate ultrasonic wave. Because the radiating rod has many radiating faces the total radiating area of transducer is large and conversion efficiency from electricity to sound is high. Because the whole length direction of radiator can radiate ultrasonic wave treatment time can be shortened and working efficiency can be improved. By setting dimension and position of two faced radiating faces on said ring rod reasonably vibrations of two radiating faces are opposite phase in basic so that superposition sound field formed by ultrasonic wave radiated by two radiated faces is strengthened and the whole radiating effect is good.

The invention relates to an electronic horn for a motor vehicle or a motor boat. The electronic horn for the motor vehicle or the motor boat comprises a booster circuit, a piezoelectric induction unit, a feedback circuit and a horn unit, wherein the booster circuit is used for carrying out boost processing on input voltage to generate boosted driving voltage, the piezoelectric induction unit is used for receiving the driving voltage generated by the booster circuit to drive a vibrating diaphragm of the horn unit to vibrate so as to give out a sound, and generating induction voltage with the oscillation frequency, the feedback circuit is used for receiving the induction voltage, and building oscillation switch-on and switch-off according to the induction voltage to control the working state of the booster circuit, the horn unit is used for vibrating to give out a sound together with the piezoelectric induction unit when the piezoelectric induction unit is driven by the driving voltage, when operation is carried out, the feedback circuit is controlled by the induction voltage to carry out switch-on and switch-off according to the oscillation frequency, and the booster circuit generates the driving voltage with the oscillation frequency. The electronic horn for the motor vehicle or the motor boat is high in electroacoustic conversion efficiency, improves the energy utilization rate, and is beneficial to energy saving and environmental protection.

The invention discloses a low-frequency broadband efficient array forming structure based on a bent disc transducer, which mainly comprises a transmitting array. The transmitting array comprises a plurality of groups of transducer units, the transmitting array is formed by arranging a plurality of groups of same transducer units at equal intervals in the horizontal direction, and the postures of the transducer units in the transmitting array are consistent; the acoustic center distance between the transducer units is not greater than the half wavelength of the transducer units at a resonant frequency point, and therefore the near-field mutual radiation influence on each group of transducer units is kept consistent; each transducer unit is formed by arranging one or more bent disc transducers in the axial direction. Radiation impedance of the bent disc transducers can be changed by arraying the bent disc transducers according to a specific arraying mode, and therefore resonant frequencyof a transmitting array is reduced; working bandwidth is expanded, electro-acoustic efficiency is improved; the transmitting array is enabled to meet development requirements of a future maneuveringdetection system.

The invention relates to the field of acoustic transducer, and provides a modulation method for modulating an airflow sound source and a sensorless closed loop. The modulation method comprises the steps of (1) with sound signals being combined with high-frequency detection signals as an input, driving a voice coil to oscillate through an audio power amplifier, (2) conducting sampling, linear amplification, filtering and orthogonal decomposition to modulated coil current signals to obtain an instantaneous phase of the modulated coil current signals, and (3) according to a correlation model between an immediate movement and the instantaneous phase, obtaining an immediate movement of the voice coil and realizing closed-loop control regulation to the position of the voice coil. The modulation airflow sound source comprises the voice coil, a pure ferromagnetic core, an audio power amplifier and closed-loop control regulator, a current sense resistor, a fine differential amplifier, a band-pass filter, a quadrature demodulator circuit and a processor. Without additional sensor or the structural integrity of a transducer being damaged in the modulation method for modulating airflow sound source and sensorless closed loop, the closed loop is low in modulation cost, high in reliability and strong in anti-interference, and suitable for work in environment such as high temperature, high pressure and high humidity.

The invention relates to a high power density piezoelectric transducer for an ultrasonic surgical instrument. The existing product has small ultrasonic power. The high power density piezoelectric transducer comprises a plurality of groups of piezoelectric transduction units, wherein a solid trumpet-shaped deformation transformation block is arranged between every two adjacent piezoelectric transduction units, and insulation layers are arranged between the piezoelectric transduction units and the deformation transformation blocks. Each piezoelectric transduction unit comprises a plurality of disc piezoelectric sheets which are coaxially arranged, metal electrodes are respectively arranged on the surfaces of the disc piezoelectric sheets, and two cone frustum-shaped metal caps are arranged between every two adjacent piezoelectric sheets. All the piezoelectric transduction units have the same height, the diameters of the piezoelectric sheets of the plurality of piezoelectric transduction units are sequentially reduced, and all the deformation transformation blocks have the same height. The center distance between two adjacent piezoelectric transduction units satisfies the dispersion equation. With the high power density piezoelectric transducer, the electroacoustic conversion efficiency is effectively increased, the ultrasonic irradiation directivity is improved, and the ultrasonic energy of a local area is improved within a limited space.