57 results about "Microphone amplifier" patented technology

A scheme is described to switch the power supply to the MEMS microphone on and off in a cyclic manner that is synchronized with the associated ADC sampling rate. In this way the MEMS microphone amplifier, whether it is a J-FET transistor or an operational amplifier, is off most of the cycle time, and is turned on only for a few micro-seconds prior to the sample-and-hold timing of the ADC device. By this method, the average power consumption of an existing analog MEMS microphone can be reduced by a factor of 10 or more.

A hearing protector device is provided including a sound attenuating body and an electronic unit having a microphone, an amplifier, and a loudspeaker, where the electronic unit is selectively activated and, when activated, receives sound from an ambient environment, amplifies a frequency range of the received sound corresponding to a frequency range of human speech, and varies said amplification such that a total level of sound passing through the body and through the electronic unit does not exceed a maximum predetermined sound level.

A microphone amplifier arrangement comprises at least one microphone input connected to a dual output microphone pre-amplifier having an input resistance comprising a first resistance and a second resistance in a first voltage-to-voltage mode of operation, and only the second resistance in a second current-to-voltage mode of operation. A first output is operably coupled to a first feedback path comprising a V2V feedback resistor; and a second output is operably coupled to a second feedback path comprising an I2V feedback resistor. In this manner, the microphone amplifier arrangement is arranged to support both a V2V microphone amplifier and a low-noise I2V microphone amplifier.

In accordance with an embodiment, a two-wire microphone includes an integrated circuit. The integrated circuit includes an amplifier having a power supply connection coupled to a first pin of the integrated circuit and a reference connection coupled to a second pin of the integrated circuit, and an impedance element having a first end coupled to an output of the amplifier and a second end coupled to a first node within the integrated circuit.

The invention discloses a near field sound source real-time positioning system based on a microphone array, belonging to the technical field of sound source positioning. The positioning system comprises a microphone array, an amplifying circuit module, a signal acquiring and processing module, a positioning result storage module and other system assistance modules. Voice signals are amplified through the microphone array, and the amplifying circuit adopts a special microphone amplifier with an automatic gain function as a core. The signal acquiring and processing module takes a DSP chip with an on-chip analog-to-digital conversion function as a core, and adopts the direct storage access function in the DSP chip. A near-field two-dimensional broadband MUSIC algorithm is further optimized, the acceptation or rejection of the microphone array signal frequency spectrum sub-band is carried out, a sub-band matrix is subjected to MUSIC spectrum estimation, the computation burden of DSP chip is reduced, and the system instantaneity is improved. The sound source positioning result storage module adopts an SD card as a storage medium, the application range of the system is improved, and thecluster chain of speaker position data is constructed by adopting a 'pre-built cluster chain method', so that the system instantaneity is improved.

A howling canceller which suppresses occurrence of howling even when an open loop gain exceeds “1” in the whole reproduction band. In the howling canceller, an adaptive filter (107) operates a digital received voice signal with a tap coefficient to generate a pseudo echo; a subtractor (108) subtracts the pseudo echo from a digital transmitted voice signal to generate a residual signal; and an amplitude limiting circuit (110) limits the absolute value of the amplitude of the digital received voice signal to be equal to or smaller than a predetermined threshold which ensures that all of a D/A converter (101), a power amplifier (102), a speaker (103), a microphone (104), a microphone amplifier (105), and an A/D converter (106) operate in a linear operation area, and outputs the amplitude-limited digital received voice signal to the D/A converter (101) and the adaptive filter (107).

A loudspeaker device for use in various sound apparatus such as a television receiver, having an acoustic pipe disposed in front of a speaker unit, the acoustic pipe being provided with a microphone for detecting sounds reproduced by the speaker unit. The sounds reproduced by the speaker unit are corrected by the signals detected by the microphone to provide flattened sound output characteristics. The speaker device comprises a power amplifier (13) to which an input signal is delivered via a subtracter (6), a speaker unit (1) for reproducing output signals delivered from the power amplifier (13), an acoustic pipe (2) coupled in front of the speaker unit (1) for guiding the sound waves, a microphone (4) for detecting an acoustic outputs radiated from the speaker unit (1), and a microphone amplifier (5) for amplifying an acoustic output signals detected by the microphone (4). Output signals of the microphone amplifier (5) are delivered to the subtracter (6), at the same time the same output signal is connected to a high-pass filter (7) to be delivered to the subtracter (6). Thus a negative feedback circuit is formed to suppress peaks and dips for providing a flattened sound pressure frequency characteristic. <IMAGE>

The invention discloses an acoustic detection method and device for egg cracks based on continuous vibration sound production. The device comprises a corrugated board, a microphone, an amplifier, a computer, a power source and a crash pad, wherein one end of the corrugated board is lifted by a theta angle, and the lower end of the corrugated board is placed on the crash pad; the microphone is closely clung to the back of the corrugated board, and the microphone is connected with an input port of the microphone of the computer through the amplifier; and the amplifier is connected with the power source, and the computer is internally provided with signal collecting and analysis software. The device provided by the invention utilizes the decay rate difference of acoustic signals of normal eggs and cracked eggs in a continuous vibration sound production process to detect the cracked eggs, and the device has the advantages of simple structure and low cost.

The invention discloses a silicon microphone amplifier capable of eliminating noise of a charge pump. The silicon microphone amplifier comprises the components of a charge pump, an input buffer, a bias buffer, a bias matching module, an amplifier and a stabilized power supply. The output end of the charge pump is connected with the high-voltage bias end of a silicon microphone device and is used for generating high-voltage bias and biasing the silicon microphone to an appropriate working voltage. The output end of the charge pump is furthermore connected with the input end of the bias matching module. The bias matching module is used for performing attenuation with a specific gain on the noise of the charge pump, thereby matching attenuation of the nose of the charge pump through a signal pathway which comprises the silicon microphone device and an input pad. The input buffer is connected with the input end of the silicon microphone device for realizing conversion between capacitance and voltage. The bias buffer is connected with the output end of the bias matching module for realizing conversion between capacitance and voltage. The amplifier is used for performing differential amplification on the output signal of the input buffer and the output signal of the bias buffer, thereby amplifying a useful voltage signal and inhibiting the noise of the charge pump.

The invention provides a power voltage regulator circuit comprising a first transistor, a first divider resistance, a second divider resistance, an amplifier and a signal processor; a source electrode of the first transistor is connected to a power supply voltage and a drain electrode of the first transistor is connected to an output voltage. the first divider resistance is in series connection with the drain electrode of the first transistor; one end of the second divider resistance is in series connection with the first divider resistance and the other end is grounded. An in-phase input end of the amplifier is connected between the first divider resistance and the second divider resistance; an anti-phase input end of the amplifier is connected with an output end of the signal processor; an output end of the amplifier is connected with a grid of the first transistor. Compared with related technologies, when the power voltage regulator circuit of the invention is applied to the microphone amplifier, the output voltage can follow the power supply voltage while providing sufficient power supply rejection ratio so as not to limit the output voltage range of the microphone amplifier and the acoustic overload point.

A loudspeaker device comprising a power amplifier (13) to which an input signal is delivered via a subtracter (6), a speaker unit (1) for reproducing output signals delivered from the power amplifier (13), an acoustic pipe (2) coupled in front of the speaker unit for guiding the sound waves, a microphone (4) for detecting an acoustic outputs radiated from the speaker unit, a microphone amplifier (5) for amplifying an acoustic output signals detected by the microphone, and a negative feedback circuit. Output signals of the microphone amplifier are delivered to the subtracter, at the same time the same output signal is connected to a high-pass filter (7) to be delivered to the subtracter. Thus the negative feedback circuit is formed to suppress peaks and dips for providing a flattened sound pressure frequency characteristic.

This invention relates to one USB interface connection line with microwave amplifier, which comprises USB interface connection wire with one end connected with microphone through plug and with other end connected with computer through USB interface composed of high property microphone amplifier, low filter, special audio collection system, power manager, 48V generator, wherein, the plug sends the micro signal to high property microphone amplifier through gains of amplifier to put microphone signal to proper level then into low filter; then sending the microphone signal to special frequency collection system.

The invention provides a microphone amplifier circuit, which comprises a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a diode and a resistor, and is characterized in that a grid electrode of the first transistor acts as an input end of the microphone amplifier circuit, and a source electrode of the second transistor acts as an output end of the microphone amplifier circuit. The fifth transistor, the sixth transistor, the seventh transistor, the eighth transistor and the resistor form a bias circuit which is used for generating bias current and providing required current for the first transistor M1 and the second transistor M2 which act as source followers, and the second transistor M2 adopts a deep-N-well NMOS (N-channel metal oxide semiconductor) transistor to generate a back gate effect. Compared with related technologies, the microphone amplifier circuit provided by the invention has the advantages of low current consumption and high SNR (Signal to Noise Ratio).

The invention discloses a voice electronic lock. The voice electronic lock adopts an SPCE061A singlechip microcomputer and comprises the following parts: (1) a voice signal acquisition part: a microphone amplifier and a single channel with an AGC (Automatic Gain Control) function are arranged inside the Sunplus singlechip microcomputer SPCE061A for voice signal acquisition; a multiplexed expansion FLASH storage part for storing characteristic parameters of a speaker is also arranged; (2) a loudspeaker output part: a dual-channel 10-bit digital/analog converter with an audio output function, which is inherently arranged in the Sunplus singlechip microcomputer SPCE061A, is utilized to complete various voice playing prompts through various operations during training and recognition by users; (3) a control output part: the corresponding actions can be controlled through a programmable control input/output port of the SPCE061A. The voice electronic lock has good stability and recognizability and good effect and is worthy of promotion and application.

A secure data transmission device: employs a proprietary arrangement of individualized encodable micro-machined electromagnets embedded in a compact, plastic (or apt substrate) which insulates each electromagnet from one another. The electromagnets mimic the magnetic strip on a credit card, but have the capability to temporarily capture data, and then transmit said data to be read by a magstripe terminal. The electromagnetic device can receive, and momentarily capture a variety of data, depending on which digital data is chosen by user. It then converts that data it to an analog signal, and then by using such components as microphone amplifier, a digital-to-analog converter, and microprocessor in the mobile device, transmits that data to the secure information device, which can write that data to a magnetic card terminal. The secure transmission device can be rewritten over and over again each time the user has a separate transaction, using different transaction data.

The present invention is a small device containing at least the following elements: a MEMS microphone, an amplifier, a microprocessor with audio frequency filters, a wireless transmitter, and a battery. The device may be placed behind the ear of the user on a bony protrusion of the skull and may be held in place by a variety of known methods, including adhesives such as spirit gum, adhesive tape, and a small circular adhesive bandage. The MEMS microphone detects sounds transmitted through the skull by bone conductance and the microprocessor analyzes the sounds to determine whether they are associated with a bruxism event. If so, data associated with the sounds are sent via the wireless transmitter to an external device. The data may be stored for later review by the user or medical professional, or may trigger a response such as an auditory or vibratory alarm.