Abstract: According to one embodiment, an electronic apparatus includes a speaker, a terminal, a first detector, a second detector, an amplifier, a power supply circuit and a control module. The terminal is configured to connect an external device via a connection member, the external device outputting an audio signal. The first detector is configured to detect that the connection member is connected to the terminal. The second detector is configured to detect that the audio signal is received via the terminal. The amplifier is configured to amplify the audio signal and to produce sound from the speaker. The controller is configured to control the power supply circuit to supply power to the amplifier, when the first detector detects that the connection member is connected to the terminal, the second detector detects that the audio signal is received, and the electronic apparatus is in an inoperative state.

Abstract: An operational amplifier capable of compensating offset voltage includes an input stage circuit having a positive input end, a negative input end, a first current output end, and a second current output end, for outputting current corresponding to voltage received by the positive and negative input ends, an output stage circuit coupled to the first current output end and the second current output end of the input stage circuit, for outputting voltage according to current outputted from the first current output end and the second current output end, and an trimming device coupled between the input stage circuit and the output stage circuit, for adjusting current of the first current output end or the second current output end for compensating offset voltage.

Abstract: A speaker device includes: a casing having a cylindrical shape which opens at one end side; and a sounding body arranged at the other end side of the casing and driven based on an audio signal, wherein a sealed space is formed by the casing and a setting surface when the casing is set, which functions as a cabinet.

Abstract: A distortion compensation system minimizes distortion in an audio system by monitoring a supply voltage and adjusting a clipping threshold and/or compression knee. An adjustable gain circuit controls the gain of the audio signal according whether the audio signal exceeds a variable threshold. The variable threshold is adjusted within a threshold range based on the supply voltage. Distortion due to clipping of the audio signal is minimized while available power at any given time is maximized.

Abstract: An audio output apparatus includes: an audio codec outputting an analog audio signal corresponding to a digital audio signal from a system controller; a switch unit having a first end coupled to the audio codec through a capacitor, and a grounded second end; and a switch controller triggered by a trigger signal to output a control signal to a control end of the switch unit such that the switch unit couples the capacitor to ground in response to the control signal. The trigger signal is generated by one of the system controller, the audio codec, and a power circuit supplying electric power to the system controller, the audio codec and the switch controller upon occurrence of a condition associated with pop noise, and is outputted to the switch controller before the pop noise is generated, such that the pop noise is conducted to ground via the switch unit.

Abstract: Systems and methods for switched-mode amplifiers having improved harmonic distortion are disclosed. High order in-band filtering is enabled without undue trade-off of distortion due to intermodulation/aliasing. A pre-modulation block is introduced, deployed between a loop filter block and a pulse-width modulation block, performing uniform pulse-width modulation. The pre-modulation block attenuates/removes amplitude dependent high frequency ripples before pulse-width modulation. The pre-modulation block in conjunction with the pulse-width modulation block performs double sampling of the input signals.

Abstract: A method of setting a parameter for an audio apparatus including a delay processing unit which applies a delaying process and an amplifying process on an input audio signal in accordance with the set parameter, includes: performing a measuring process including: causing an outputting device to output measurement sound; and measuring a first impulse response at a sound receiving point; performing a specifying process including: analyzing the measured first impulse response; calculating a second impulse response at the sound receiving point when the outputting device outputs sound in case where a parameter is set in the audio apparatus and an audio signal indicative of the measurement sound is input to the audio apparatus; and specifying a parameter in accordance with the calculated second impulse response; and performing a setting process of setting the specified parameter in the delay processing unit.

Abstract: A preamplifier arrangement for a drum microphone, in which drum the microphone is arranged inside the drum and wherein the microphone is connected to a preamplifier, characterized in that the preamplifier is secured to the side wall or bottom of the resonance chamber of the drum via a mounting arrangement comprising a threaded part, which is fastened to the preamplifier and fitted through a hole in the side wall or bottom, and a counterpart for it.

Abstract: Two control voltages are generated, one increasing and another decreasing, in response to the rise of the voltage of a condenser of a common time-constant circuit. Based on the two control voltages, a first and a second currents are formed, from which four different combinations of currents are established. By feeding one of four combinations to each of multiple differential output amplifier circuits each having a feedback resistor, the multiple output amplifier circuits can be individually started up or shut down without generating popcorn noise, using only one single time constant circuit.

Abstract: A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage.

Abstract: A procedure and device for linearizing the characteristic curve of a vibration signal transducer such as a microphone that includes collecting signals, transmitting the signals, extracting information from the signals, dephasing such information by 180 degrees compared to the initial signals and taking the algebraic sum of the initial signals and dephased information.

Abstract: An audio control method and audio processing system utilize an ADC to sample an analog audio input signal and convert it to a digital audio signal. A control module determines input signal level from the digital audio signal. Based on different input signal levels, output gain range of the amplifier can be set. In this way, the present invention can prevent speakers being burned out or volume being too low.

Abstract: Techniques for controlling one or more audio amplifiers in or associated with a device coupled on a local area network are disclosed. The device receives at least one selected source from other devices also coupled on the network According to one aspect of the techniques, an automatic shutdown control module is provided in the device to power down the audio amplifiers when there is no audio data flow coming to the device or power up the audio amplifiers when there is audio data flow coming to the device. In one embodiment, the procedure to power down or power up the amplifiers is in accordance with a hysteresis, wherein the hysteresis, being lagging of an effect behind its cause, protects the amplifiers and makes the powering-down or powering-up procedure unnoticeable to a user.

Abstract: A piezoelectric buzzer driving circuit (200) for driving a piezoelectric buzzer (211) with two terminals includes a reverser (216). The reverser includes an output terminal and an input terminal (24) configured for receiving a controlling signal to control an output of the reverser. The two terminals of the piezoelectric buzzer respectively connected to the input terminal and the output terminal such that a D-value of the voltage across the piezoelectric buzzer is twice as large as the voltage of the controlling signal.

Abstract: A speaker drive integrated circuit of the present invention includes: a load connection status detecting circuit configured to cause a current to flow from an external power supply to one of output terminals when an output side of an amplifying circuit is set to a high impedance state and detect whether a load connection status is normal, open, or short based on a voltage generated at the output terminal; and a transmitting terminal through which a signal indicating a detection result by the load connection status detecting circuit is output to outside.

Abstract: An apparatus and method for outputting a sound with Hearing Aids Compatibility (HAC) in a mobile terminal. The sound output apparatus includes a modem chip including a first amplifier amplifying and transferring an electric signal to a switch, a switch that selectively connects an output line of the first amplifier to a receiver or a second amplifier, a second amplifier connected with the receiver and the switch and that amplifies and transfers an electric signal received from the first amplifier to the receiver when the switch connects the output line of the first amplifier to the second amplifier, and a receiver connected with the switch and the second amplifier and that converts and outputs an electric signal received from the first amplifier or the second amplifier into a sound. This allows for the stable transfer of a sound to hearing handicapped persons with HAC without distortion of the sound quality.

Abstract: The present invention is a stereo PA amplifier that is mounted inside a desktop computer. It is powered by the computer's 12-volt power supply and receives its input via a stereo mini cable from the computer's audio line out. Standard 8-ohm, non-powered speakers are then hooked up directly to the board via its speaker connector board. The volume of the present invention is adjusted by the computer's volume controls. The device eliminates the need for an external stereo amp and external mixer, which thereby reduces the installation time, cost, interconnecting cables, and the space needed for the overall computer system, while at the same time providing quality sound.

Abstract: An audio output circuit includes an on-chip left channel amplifier module, an on-chip center channel amplifier module, and an on-chip right channel amplifier module. A left channel IC pin is operably coupled to an output of the on-chip left channel amplifier module. A right channel IC pin is operably coupled to an output of the on-chip right channel amplifier module. A center channel IC pin is operably coupled to an output of the on-chip center channel amplifier module. A center channel feedback IC pin is operably coupled to an input of the on-chip center channel amplifier module to provide a feedback loop. A left jack connection is operably coupled to the left channel IC pin. A right jack connection is operably coupled to the right channel IC pin. A jack return connection coupled to the center feedback IC pin. An inductor has a first node coupled to the jack return connection and a second node coupled to the center channel IC pin.

Abstract: According to one embodiment, an electronic apparatus includes a speaker, a terminal, an amplifier, a battery, a power supply circuit, and a controller. The terminal is configured to input an audio signal from an external device. The amplifier is configured to amplify the audio signal which is input from the terminal, and to output audio from the speaker. The power supply circuit is configured to supply power from the battery to the amplifier. The controller is configured to control the power supply circuit, based on a residual capacity of the battery and a preset battery level, in order to supply the power to the amplifier when the electronic apparatus is in a non-operative state.

Abstract: The present invention discloses a half-voltage headphone driver circuit, comprising: at least one operational amplifier providing an output to a headphone speaker, and a charge pump receiving a supply voltage (VDD), generating a positive half-voltage and a negative half-voltage (VDD/2 and ?VDD/2) based on the supply voltage, and supplying the positive half-voltage and negative half-voltage as high and low operation levels to the at least one operational amplifier.

Abstract: A method for controlling a gain applied to an audio signal. The method comprises applying a gain step to a gain setting at defined time intervals, and upon detection of at least one zero crossing point within the audio signal, applying the gain setting to a gain control signal for controlling the gain applied to the audio signal.

Abstract: A multi-port combiner for an audio amplifier is configured with a plurality of series-parallel coupled connection ports to enable one or more speaker monitors coupled thereto to receive audio signals from a single output port of the amplifier. The multi-port combiner also includes a phantom load having an impedance that is equivalent to that of one of the speaker monitors. As such, the phantom load is selectively coupled to the connection ports to maintain the series-parallel configuration of the connection ports, so that the equivalent impedance of all the speaker monitors coupled to the multi-port combiner is maintained within an acceptable operating range established by the amplifier.

Abstract: A speaker system utilizes input from a transducer that receives an acoustical signal produced by a speaker that is separate from the speaker system. The acoustical signal is amplified and drives a speaker of the speaker system. The speaker system is thereby provided with the necessary electrical audio signal without the speaker system being wired into any existing sound system wiring. In automobiles, the transducer is in proximity to a speaker wired into the automobile's audio system, and the transducer obtains the acoustical signal to produce the electrical audio signal used by the speaker of the speaker system so that no access to high or low level electrical audio signals of the audio system of the automobile is necessary. Additionally, the speaker system may employ a power socket plug that is electrically coupled to the power input of the amplifier and that may be plugged into a power socket such as those typical of most vehicles to provide electrical power to the amplifier of the speaker system.

Abstract: Methods and apparatus provide for: a rectification circuit operating to convert a source of AC power into a final DC power source; a rectification filtering capacitance operating to at least partially smooth a voltage of the final DC power source, which exhibits a voltage sag and recovery characteristic in response to time-variant current drawn therefrom; a power amplification circuit drawing power from the final DC power source and producing an output signal, for driving a speaker, having audible characteristics influenced by the voltage sag and recovery characteristic of the final DC power source; and a control circuit operating to continuously vary, in response to user input, one or more parameters of the voltage sag and/or recovery characteristic of the final DC power source.

Abstract: An audio signal amplifying device and method for reducing a size and corresponding power consumption of demodulation filters in the signal amplifying device. In the device and method, carrier waves having phase shifts are generated from a received audio signal. The shifted carrier waves are compared to the audio signal to generate modulation signals, which are amplified based on a power supply voltage. The amplified modulation signals or a power supply signal are output based on a comparison between the carrier waves and the audio signal. The output signals are synthesized to produce a synthesized signal having a lower average voltage and current value, thus reducing power consumption of the signal amplifying device.

Abstract: An audio processing apparatus comprising: channel determination section for determining which one of a combination of the first left audio signal and the first right audio signal and a combination of the second left audio signal and the second right audio signal is included in multichannel audio data; and switching section for causing the first amplification section to amplify the first left audio signal and supply the amplified first left audio signal to the first speaker terminal and causing the second amplification section to amplify the first right audio signal and supply the amplified first right audio signal to the second speaker terminal when the combination of the first left audio signal and the first right audio signal is determined to be included; and causing the first amplification section to amplify the second left audio signal and supply the amplified second left audio signal to the third speaker terminal and causing the second amplification section to amplify the second right audio signal and su

Abstract: A speaker diaphragm containing resin and carbonized bamboo material with a large degree of flexibility in setting physical properties, moisture-proof reliability and strength secured, superior appearance, and productivity and dimensional stability increased, which allows making characteristics and sound highly accurately, and designing with great originality.

Abstract: A ribbon loudspeaker module includes a ribbon element of electrically conductive material and having a resistance of less than 1? and a magnetic system arranged to create a magnetic field about the ribbon element. A buffer amplifier having an input is arranged to receive a loudspeaker drive signal from an audio power amplifier and an output arranged to drive the ribbon element directly. The ribbon loudspeaker module is preferably a low frequency module, designed to handle audio signals below 5 kHz, and preferably in the range 20 Hz to 3 kHz or a part thereof. The ribbon element may have a resistance of less than 0.5?, less than 0.2? and even as little as 0.15? or less.

Abstract: The present invention is directed to products, product packaging, or product displays containing an electrical component (30) integrated therein. The electrical component could be a lighting component (34), a sound component (36) or a combination of the two.

Abstract: A speaker system includes a first speaker, a second speaker and a driving circuit. The first speaker and the second speaker are different types of speakers. The driving circuit drives the first speaker with a first driving voltage and a first driving current and drives the second speaker with a second driving voltage and a second driving current, wherein the first driving voltage is larger than the second driving voltage and the first driving current is smaller than the second driving current. The present disclosure further provides a speaker driving circuit.

Abstract: An inverting amplifier which drives headphones via an output capacitor includes: an operational amplifier, an input resistor having a first terminal via which an audio signal to be amplified is received, and a second terminal connected to an inverting input terminal of the operational amplifier; and a feedback resistor having a first terminal connected to an inverting input terminal of the operational amplifier, and a second terminal connected to the output terminal. A reference voltage source generates a bias voltage Vb, and supplies it to the non-inverting input terminal. A discharging path includes a discharging resistor and a first switch arranged in series between an output terminal of the reference voltage source and an fixed voltage terminal. A second switch is arranged between the output terminal of the operational amplifier and a node on the discharging path where the electric potential is higher than it is at the discharging resistor.

Abstract: According to one embodiment, an electronic apparatus includes a speaker, a terminal, an amplifier, a power supply circuit, a setting module, a detection module, and a controller. The terminal is configured to input an audio signal from an external device. The amplifier is configured to amplify the audio signal, and to output audio from the speaker. The power supply circuit is configured to supply power to the amplifier. The setting module is configured to set data which indicates whether audio output from the speaker is to be enabled or disabled when the apparatus is in a non-operative state. The detection module is configured to detect a predetermined state of the apparatus. The controller is configured to control the power supply circuit, based on the data and the predetermined state, in order to supply the power to the amplifier when the apparatus is in the non-operative state.

Abstract: The invention relates to an audio amplifier (1) for amplifying an input signal into an output signal, comprising an output amplification stage (6), wherein the output amplification stage (6) for the amplification of an intermediate signal into the output signal is designed as an amplifier operating in switching operation, and further comprising a limiter device (4), which from a programming and/or a circuit design point of view is designed to generate the intermediate signal on the basis of the input signal, wherein the level of the intermediate signal is always limited by a maximum load as a function of a settable maximum output and a load impedance which is coupled and/or can be coupled the audio amplifier or equivalent parameter thresholds such that the output signal does not exceed the maximum load at the load impedance, or the equivalent parameter thresholds, independently of the input signal.

Abstract: A condenser microphone is obtained, in which the bias of a current amplifier circuit in emitter-follower connection immediately after an impedance converter automatically changes in accordance with the switching of phantom power supply voltages and the maximum output level and the maximum permissible input sound pressure level are increased at any power supply voltage. The condenser microphone comprising a transistor Q2 in emitter-follower connection immediately after an FET 2 that constitutes an impedance converter Q1 has a constant current diode D2 connected to an output transformer TRS that also serves as a transformer for phantom power source supply and resistors R0 and R1 that divide the voltage on the cathode side of the constant current diode D2 into a bias voltage that causes the transistor Q2 to operate.

Abstract: A signal processing device includes a non-inverting amplifier, an inverting amplifier, a converter, and a controller. The non-inverting amplifier amplifies a level of an analog sound signal input from outside with a first gain whose value is variable. The inverting amplifier amplifies a level of the analog sound signal amplified by the non-inverting amplifier with a second gain whose value is variable. The converter converts the analog sound signal amplified by the inverting amplifier to a digital sound signal. The controller detects a level of the digital sound signal converted by the converter and, in accordance with the detected level of the digital sound signal converted by the converter, controls the first gain and the second gain such that a level of the analog sound signal input to the converter is at a pre-specified level.

Abstract: According to a first aspect, a method of controlling an electronic system includes the step of receiving by a first device a plurality of receivable wireless signals that are intended to control functions of a second device. The first device transmits a wireless signal that prevents a subset of the plurality of receivable wireless signals from controlling the second device.

Abstract: A configurable amplifier circuit for a karaoke player is described. In one embodiment, a karaoke player includes: a DVD/CD reader port for coupling to a DVD/CD reader, a microphone input to receive audio signals from an external microphone, an MPEG decoder coupled to the DVD/CD reader port and the microphone input, the MPEG decoder having first and second output terminals, a processor coupled to the MPEG decoder, the processor to control the MPEG decoder, and a configurable amplifier coupled to the first and second output terminals, wherein a first audio signal originating from the first output terminal is selectively amplified by the configurable amplifier circuit in accordance with a second signal originating from the second output terminal.

Abstract: An electronic amplifier for driving a capacitive load may include first and second differential input terminals to receive an input signal, and first and second differential output terminals to provide a differential output signal. The amplifier may further include a first operational device having first and second differential inputs connected to the first and second differential input terminals, respectively, and an output connected to the first differential output terminal, and a second operational device having first and second differential inputs connected to the first and second differential input terminals, respectively, and an output connected to the second differential output terminal. The first and second operational devices may be operatively configured so that both the first and the second output terminals are at a same reference potential during periods in which a module of differential output signal amplitude decrease.

Abstract: A switching section causes the first amplification section to amplify the expansion left audio signal and supply the amplified expansion left audio signal to the first speaker terminal and causing the second amplification section to amplify the expansion right audio signal and supply the amplified expansion right audio signal to the second speaker terminal when the Bi-Amp function is not used. The switching section causes the first amplification section to amplify the left audio signal for Bi-Amp and supply the amplified left audio signal for Bi-Amp the first speaker terminal and causing the second amplification section to amplify the right audio signal for Bi-Amp and supply the amplified right audio signal for Bi-Amp to the second speaker terminal when the Bi-Amp function is used.

Abstract: Systems for an expander circuit are disclosed. An expander circuit comprising a transmit amplifier for amplifying electrical signals received from a microphone. A rectifier circuit is responsive to the electrical signals and generates a D.C. voltage. A dynamic resistor circuit is coupled to the transmit amplifier for regulating the gain of the transmit amplifier. The dynamic resistor circuit includes a bipolar junction transistor for receiving the D.C. voltage. The bipolar junction transistor is operated such that the collector current is zero and the bipolar junction transistor has a variable impedance seen by the transmit amplifier dependent upon the D.C. voltage.

Abstract: An apparatus and method for biasing each amplifier of an amplification stage provides that the voltage across each current sensing element of each amplifier of the amplification stage is measured. For each pair of voltage measurements taken, a sum and difference is calculated, where the sum is processed to determine minima peaks and the difference is averaged. A portion of the sum term and the average of the difference term are summed to yield the individual bias current conducted by a first amplifier of the amplification stage. The difference between a portion of the sum term and the average of the difference term is calculated to yield the individual bias current conducted by the second amplifier of the amplification stage. The bias current conducted by the first and second amplifiers may then be individually modified manually, or conversely, may be modified automatically based upon the bias current measurements taken.

Abstract: The potential of a smoothing capacitor for a speaker is smoothly changed by controlling the potential with use of a PWM signal and switching between outputting the PWM signal and an actual audio signal, thereby suppressing a pop sound. The scale of circuitry is reduced and cost is lowered by implementing a PWM circuit in a one-chip microcontroller. Noise is eliminated by outputting a pulse that has been divided in the PWM signal generation stage.

Abstract: According to one embodiment, an electronic apparatus includes a terminal, an amplifier, a speaker, a power supply circuit, a first switch and a first controller. The terminal configured to input an audio signal from an external device. The amplifier configured to amplify the audio signal which is input from the terminal. The speaker configured to output sound corresponding to the audio signal which is amplified by the amplifier. The power supply circuit connected to the amplifier. The first controller configured to control the power supply circuit in order to supply the power to the amplifier, when the electronic apparatus is in a non-operative state and the first switch is turned on.

Abstract: According to one embodiment, an electronic apparatus includes a terminal, an amplifier, a speaker, a power supply circuit and a first controller. The terminal configured to input an audio signal from an external device. The amplifier configured to amplify the audio signal. The speaker configured to output sound corresponding to the audio signal which is amplified by the amplifier. The power supply circuit configured to supply power to the amplifier. The first controller configured to control the power supply circuit to continue the supply of the power, when the electronic apparatus is in a non-operative state.

Abstract: The present technology is directed to class G audio amplifiers and the associated methods of operation. In one embodiment, a class G audio amplifier includes an input port, an audio output stage, a level detector, and a charge pump. The class G audio amplifier regulates the power supplies of the audio output stage according to the input signal, so as to realize high efficiency and high quality audio output.

Abstract: Natural fiber is beaten with a biaxial kneading machine. The beaten natural fiber is processed finely with a bead mill so as to allow the processed natural fiber to have a BET specific surface area not smaller than 1 m2/g. This method provides fine fiber in a short time to form a rigid paper component.

Abstract: The present invention is related to an improved power amplifier and a method for restraining power of the improved power amplifier. The improved power amplifier has an output power restraint unit, and the output power restraint unit is capable of restraining output power of the improved power amplifier when the output power is exceedingly large. A method for restraining power of a power amplifier, the method comprises the steps of: determining whether power of output powers signal are exceedingly large through a power signal transformation unit, if yes, adjusting two variable resistor of an input amplifier unit for adjusting the power of the power signals, and outputting the adjusted power signals for driving a load via output terminals of the power amplifier.

Abstract: A light-powered loudspeaker system including a solar power generator, a power storage device, a wireless signal receiver, a power amplifier and a speaker module is disclosed. The solar power generator is configured to receive a solar energy and convert the received solar energy into electricity energy. The power storage device is coupled to the solar power generator for storing the converted electricity energy. The wireless signal receiver is coupled to the power storage device, receives wireless audio signals and generates an output signal. The power amplifier is coupled to the power storage device and the wireless signal receiver, amplifies the output signal and generates an amplified audio signal. The speaker module is coupled to the power amplifier and produces voices according to the amplified audio signal.

Abstract: An improved self-oscillating audio amplifier and a method for restraining audio distortion of the self-oscillating audio amplifier are disclosed. The improved self-oscillating audio amplifier comprises a distortion restraint unit configured to detect whether modulated audio signals outputted from the self-oscillating audio amplifier is distorted and, if so, to restrain the distortion. The method for restraining audio distortion of the self-oscillating audio amplifier includes the following steps of: determining whether the modulated audio signals outputted from an audio amplifier positive output terminal is distorted by a first flip-flop set, and if yes, restraining the distortion of the modulated audio signals outputted from the audio amplifier positive output terminal; and outputting the modulated audio signals to drive a speaker by the audio amplifier positive output terminal and an audio amplifier negative output terminal.

Abstract: An open-loop switching amplifier achieves synchronous operation using a ring oscillator based upon a tapped delay line. A counter is clocked from the ring oscillator, periodically comparing incoming more significant data to the value of the counter to form a pulsewidth modulated output waveform. Modulating the effective width of the output waveform in incremental delay line taps is equivalent to incoming less significant data. This technique then effects time-period summation of coarse and fine resolution clocked data.