176 results about "Electret microphone" patented technology

The invention relates to a pressure-sensitive handwriting pen, which comprises a continuous quantity pressure sensor arranged in a pen point and a front-end adapter circuit, a signal conditioning circuit and an output unit for outputting wired or wireless signals which are matched with the pressure sensor, wherein the continuous quantity pressure sensor has a unique mapping relationship between an output value and pressure. The pressure-sensitive handwriting pen can use a resister strain foil, a Hall element, an electret capacitor or an electret microphone, a variable capacitor and a variable inductor as a pressure sensor element, and aiming at handwriting light pens and handwriting ultraphonic pens, provides an implementation scheme that by utilizing the conventional infrared transmission unit on a handwriting pen, handwriting pressure data and the original signal system are integrated to transmit pressure data. By applying the pressure-sensitive handwriting pen, on one hand, the change of calligraphy is more abundant and is closer to natural writing, and on the other hand, the application of handwritten input products on aspects of calligraphy, painting and the like and particularly the pressure-sensitive handwriting on display screens is expanded. Various sensors used by the pressure-sensitive handwriting pen have the advantages of low cost and simple adapter circuit, and thus the pressure-sensitive handwriting pen is suitable to be popularized and used.

The coupling of an electret microphone is detected and identifying whether there is monaural or stereo speakers coupled to the USB connector is accomplished by coupling a current source to the USB ID terminal and detecting the voltage on the ID terminal. If the voltage on the ID line is substantially below the voltage associated with any other accessory when an electret microphone is coupled between the ID terminal and the ground terminal, and a microphone bias resistor is coupled to the ID line. On detection of an electret microphone being coupled between the ID terminal and the ground terminal, whether there is a monaural or stereo speakers coupled to the USB connector is determined by detecting the impedance on the one of the D+ and D− terminals to which a monaural speaker would not be coupled. An open circuit indicates a monaural speaker, otherwise stereo speakers are connected. An alternate embodiment is disclosed.

The invention discloses an in-car retention early warning adjusting system and method. The in-car retention early warning adjusting system comprises a detecting part, a control treatment part and an executing part. The in-car retention early warning adjusting system is characterized in that the detecting part is installed at a roof lamp and comprises a temperature sensor, a carbon dioxide sensor, a radar wave sensor and a sound sensor; an exploring port of the radar wave sensor is perpendicular to the ground, the exploring angle is adjusted to be in the mode that within a radar wave detecting range, radar waves do not transmit out of car windows while the radar waves cover seats; the sound sensor is internally provided with a capacitive electret microphone sensitive to sound, and the control treatment part comprises a single chip microcomputer, signal filter magnifying modules and an adjusting button; the single chip microcomputer is connected with the sensors of the detecting part one by one through the signal filter magnifying modules, and after signals detected by the sensors of the detecting part and signals input by the adjusting button are processed, grading control is conducted on the executing part. The in-car retention early warning adjusting system has the characteristics that the structure is simple, in-car retention organisms can be effectively stored, and the in-car environment comfort is intelligently adjusted and controlled.

The present invention is an extremely low frequency (ELF) microphone and acoustic measurement system capable of infrasound detection in a portable and easily deployable form factor. In one embodiment of the invention, an extremely low frequency electret microphone comprises a membrane, a backplate, and a backchamber. The backchamber is sealed to allow substantially no air exchange between the backchamber and outside the microphone. Compliance of the membrane may be less than ambient air compliance. The backplate may define a plurality of holes and a slot may be defined between an outer diameter of the backplate and an inner wall of the microphone. The locations and sizes of the holes, the size of the slot, and the volume of the backchamber may be selected such that membrane motion is substantially critically damped.

An alternative sensing circuit for a micro-electro-mechanical system (MEMS) microphone and a sensing method thereof are provided. The sensing circuit reads out output signals of an MEMS electret microphone or an MEMS condenser microphone. In considering different operating requirements of the different MEMS microphones, for example, low power consumption for the MEMS electret condenser microphone or high sensitivity for the MEMS condenser microphone, the manner of using two kinds of MEMS microphone sensing components in one circuit can significantly increase the flexibility of using the MEMS microphone and can be applied to the application or design of a condenser sensing component.

The invention discloses a vehicle-mounted microphone with a casing adopting bi-color injection molding. The vehicle-mounted microphone with the casing adopting the bi-color injection molding comprises a microphone casing, an electret microphone, a circuit board, a wiring harness and an inserting member. One end of the wiring harness butts against a positive and negative pad on the circuit board, the other end of the wiring harness is inserted in a corresponding groove of the inserting member through a terminal after crimping, and the electret microphone is in welding connection with the circuit board through positive and negative pins. The vehicle-mounted microphone further comprises a dustproof plug, the microphone casing comprises an upper casing and a lower casing, the upper casing and the lower casing comprise an upper casing base, a lower casing base, an upper casing cladding layer and a lower casing cladding layer respectively, the cladding layers and the casing bases are molded into a whole body through injection by means of a bi-color injection molding process, a microphone chamber formed between the upper casing and the lower casing is used for accommodating the electret microphone, and a dustproof chamber is used for accommodating the dustproof plug. The vehicle-mounted microphone with the casing adopting the bi-color injection molding can avoid vibration, protects the microphone, is high in manufacturing efficiency and good in slip resistance and cushion performance, saves cost, and can prevent dust. The casing and internal components are combined stably.

The invention belongs to the technical field of on-line temperature monitoring of a wall cooled wall, and particularly relates to a system for monitoring the fire facing side wall temperature of a water cooled wall of a power station boiler on line, and a monitoring method. The section of a furnace is provided with sound wave receiving and sending systems, each sound wave receiving and sending system consists of a sound wave guide pipe, an electrodynamic loudspeaker, and a special electret microphone; and receiving and sending measurement points of the sound wave receiving and sending systems are distributed on a heating side of the same side of the water cooled wall. The method comprises the following steps of: sending sound signals by the electrodynamic loudspeaker, receiving the sound signals and converting the sound signals into voltage signals by an enhanced microphone simultaneously, allowing the voltage signals to pass through a cable input signal conditioner and enter a data acquisition card, and converting the voltage signals into digital signals; obtaining time of flying by generalized cross correlation time delay estimation; and calculating the fire facing side wall side temperature of the water cooled wall by a computer and software. The system is not limited by severe environments such as high temperature, corrosion, dustiness and the like in the furnace, can truthfully reflect the fire facing side wall side temperature of the water cooled wall, avoids pipe explosion phenomena, and reduces accident rate and operation cost.

The invention provides a mobile terminal with a microphone. The mobile terminal comprises a shell and a circuit board which is arranged in the shell, wherein the shell is provided with a sound inlet passage; the shell is provided with an extension part on the inner side corresponding to the sound inlet passage; an electret microphone is placed in an accommodating cavity formed by the extension part; and a sound receiving face of the microphone faces the sound inlet passage and the microphone is fixed on the circuit board through an electrical connection part at the other end. Due to the design of the mobile terminal, the consistency of audio frequency of the microphone can be guaranteed, and the audio frequency performance can be improved.

The invention relates to an electret microphone. The electret microphone comprises a shell, a membrane component, an insulating gasket and a back electret component which are arranged in the shell in sequence, wherein the shell comprises a square bottom plate, a square circuit board and a square column-shaped support body arranged between the bottom plate and the circuit board; an inner cavity for accommodating the membrane component, the insulating gasket and the back electret component is arranged in the support body, and both ends of the support body are sealed by the bottom plate and the circuit board; and the back electret component is electrically connected with the circuit board. The top part of the electret microphone is directly sealed by the flat panel-type circuit board, and the smoothness of the top part of the electret microphone is much higher than that of shell edges curled by the traditional method, so that the SMT difficulty of the electret microphone is lowered, and the qualification rate of products is improved.

An electret microphone comprises a back plate having a stationary back electrode and secured to a substrate. An electret layer is formed on the stationary back electrode and a spacer is mounted on the back plate. A diaphragm electrode is mounted on the spacer.

The invention provides an acoustics and electromagnetism-based thunder positioning system and method. The system comprises a sound source positioning device, a synchronous data acqusition card and a data processing device, wherein the sound source positioning device comprises at least three sound pickups and one antenna; the plane of the three sound pickups and the horizontal plane form an acute angle of being smaller than 90 degrees; the synchronous data acqusition card is in signal connection with the three sound pickups respectively; the data processing device is in signal connection with the synchronous data acqusition card and the antenna and is used for acquiring position of thunder on a map according to different thunder sound information and time information received by the three sound pickups and acquired by the synchronous data acqusition card. The system and the method have the beneficial effects that the system has a simple structure, and the influence of factors such as landform on observation due to longer thunder distance, the influence of noise amplitude in monitoring of a surrounding environment at different time periods and error influence caused by individual difference of directivity and amplitude response nonlinearity of an electret microphone and the like are effectively reduced.

The invention relates to a heart sound transmission and management system based on NFC (Near Field Communication) and the Bluetooth. The heart sound transmission and management system consists of a heart sound acquisition hardware module and an Android-cellphone upper computer, wherein the heart sound acquisition hardware module consists of a medical auscultation head, an electret microphone, a filtering circuit, a dsPIC chip circuit, an HC-05 Bluetooth module and a Samsung TecTilesNFC tag; the Android-cellphone upper computer completes the acquisition and storage of heart sound, and supported Android applications of the Android-cellphone upper computer mainly comprise an NFC response module, a Bluetooth matching module, a heart sound acquisition module and a data management module. According to the heart sound transmission and management system based on the NFC and the Bluetooth, the heart sound signal acquisition process for a user is simplified, the heart sound signal acquisition for the user can be completed conveniently and quickly by using the system, and heart sound signal data transmission is completed through wireless transmission technologies based on the NFC and the Bluetooth.

Microphones are used in acoustically insulated masks to prevent the speaker's voice from being overheard by others. Frequently, the microphone provides an input to speech recognition software. The environment inside the mask is often humid and the speaker's mouth is in close proximity to the microphone. The shape of the mask's shell and the restricted volume within the shell introduce distortion and the signal suffers further from clipping and distortion caused by the large signals and nonlinear response of the microphone circuitry. The use of an electret microphone is particularly troublesome due to its high sensitivity. This invention uses a resistor connected in parallel with the microphone to reduce the sensitivity of an electret microphone used in these conditions and produces a signal suitable for use with speech recognition software. The resistor can be varied for different speakers.

A microphone buffer circuit being adaptable for connection to a power source is disclosed. The microphone buffer circuit includes an input transistor operably connected between an input and an output for buffering an input signal. The microphone buffer circuit includes a means for reducing power supply noise capable of being coupled to the input transistor wherein the means being operably connected to the input transistor and the power source.

The invention discloses a diaphragm laser cutting device. The diaphragm laser cutting device comprises a laser generator, a locating tool and a position adjusting mechanism, wherein the laser generator is used for enabling diaphragm ring single bodies to be cut out on a diaphragm, the locating tool is used for fixing the diaphragm, and the position adjusting mechanism is used for adjusting the relative position of the locating tool and the laser generator. According to the diaphragm laser cutting device, mass cutting can be carried out on vibrating diaphragms of electret microphones by using laser equipment, and the cutting precision of the vibrating diaphragms is high.

The invention discloses a control circuit and method based on a sound-light control energy-saving LED lamp, and the circuit comprises a lamp cap and a control module disposed on the lamp cap. The control module comprises a power module which is connected with an intelligent sensor module and an LED lamp light source. The intelligent sensor module comprises a sound and light signal collection device and a microprocessor, which are connected through an LED lamp drive circuit. The sound and light signal collection device comprises an electret microphone, a photoresistor R, a sound signal amplification conditioning circuit, and an A/D converter, wherein the electret microphone, the photoresistor R, the sound signal amplification conditioning circuit and the A/D converter are connected sequentially. The output end of the A/D converter is connected to the microprocessor. The circuit employs the intelligent sensor to carry out data collection and processing, and the microprocessor carries out the data storage and logic judgment. The microprocessor also carries out the linearization processing of the collected sound and light signals, and carries out the automatic compensation of parameters, such as temperature and static pressure. The system enables the collection sensitivity, resolution and precision of the sound and light signals to be higher, is high in response speed, is high in control precision, and is safe and reliable.

The invention belongs to the field of power station boiler flue gas monitoring and particularly relates to a monitoring system and a monitoring method for boiler furnace flue gas velocity based on acoustics. Measure points with each two 4-6 meters away from each other are reserved on the inner wall of one side of a furnace with flue gas flowing, a set of monitoring device is mounted at each measure point. Each monitoring device is structurally characterized in that an acoustic wave transceiver composed of an acoustic wave conduit, an acoustic wave generator and an electret microphone is disposed at the measure pint. The acoustic wave generators are connected to power amplifiers, and the power amplifiers are connected with output ends of wiring boxes. The electret microphones are connected to signal conditioners, and the signal conditioners are connected with input ends of the wiring boxes. The wiring boxes are connected with double-channel data acquisition cards which are connected to industrial personal computers. The defects that flue gas is unstable, and flue gas measurement is inaccurate due to uneven distribution of velocity in the flue are overcome by multi-point sampling. The monitoring system and the monitoring method are prevented from limitation from severe environments such as high temperature, corrosion and dustiness in a boiler, flue gas velocity in the boiler is reflected truly, response is quick, and measuring range is wide.

In a hearing device with multiple microphones, and a signal generation method, the dynamic range of hearing devices is improved by using a combination including a silicon microphone and an electret microphone for the hearing device input. Low frequencies thus can be acquired by the silicon microphone and high frequencies can be acquired by the electret microphone, in order to generate a wide-band hearing device input signal. The fact that a silicon microphone possesses a lower internal noise than a conventional electret microphone at low frequencies is utilized.

The invention relates to an electret microphone. The electret microphone comprises a shell and a membrane component, an insulating gasket, a back electret component, an insulating cavity and a circuit board component which are arranged in the shell in sequence, wherein the back electret component is electrically connected with the circuit board component; and the shell comprises a bottom shell and a top shell, the bottom shell and the top shell are sleeved to form an accommodating cavity for accommodating the membrane component, the insulating gasket, the back electret component, the insulating cavity and the circuit board component, the circuit board component is arranged close to the top shell, and the surface, parallel to the membrane component, of the top shell, is a plane. The top shell of the electret microphone is directly manufactured by a mold, and the smoothness of the top part is much higher than that of shell edges curled by the traditional method, so that the SMT difficulty of the electret microphone is lowered, and the qualification rate of products is improved.

There is disclosed a microphone, a circuit, and a method. A microphone capsule may include an electret microphone and a field effect transistor (FET). A floating DC voltage source may have a first end connected to a drain terminal of the electret microphone capsule and a second end. A load resistor may be connected between the second end of the floating DC voltage source and a source terminal of the electret microphone capsule. A voltage follower may have an output connected to the source terminal of the electret microphone capsule and the first end of the floating DC voltage source. A coupling capacitor may couple an audio signal from the source terminal of the electret microphone capsule to an input of the voltage follower.