Abstract: A shelf is equipped with an audio amplifier and at least one loudspeaker. The shelf can be integrated into the interior design as a shelf while providing multimedia use for audio playback, video output, and connection to a computer, as well as serve for the high-quality enjoyment of music and its functional application, using only one device.

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: An audio amplifier and a method of operating such an amplifier are disclosed. The audio amplifier includes a switch disabling controller and/or an output set-point controller. The switch disabling controller is configured to disable switching of an output switch circuit or other switch circuit while an input signal represents at least relative silence. The output set-point controller is configured to bring and/or hold first and second switch nodes toward and/or at a set-point voltage while the input signal represents at least relative silence.

Abstract: The present invention relates to a microphone assembly comprising a microphone assembly casing having a sound inlet port and a transducer for receiving acoustic waves through the sound inlet port. The transducer converts the received acoustic waves to analog audio signals. The assembly according to the present invention further comprises an electronic circuit positioned within the microphone assembly casing, said electronic circuit comprising a pre-amplifier and an analog-to-digital converter preferably in form of a sigma-delta modulator so as to convert amplified analog audio signals to digital audio signals.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries. Various examples of efficiently generated regulation-compliant audible alerts and further enhancing such audible alerts by utilizing speaker enclosure designs are provided.

Abstract: An audio console system includes an input for receiving an audio signal. The system may also include a user adjustable input amplifier which may amplify audio signals received from the input with a predefined gain. The system may additionally include a direct out output amplifier provided after the adjustable input amplifier. The direct out output amplifier may output a direct out output signal. The direct out output amplifier may adjust a gain of a signal transmitted from the adjustable input amplifier. The direct output amplifier may be configured in such a way, that, upon a user adjustment of the adjustable input amplifier, the direct out output amplifier may adjust the gain of the direct out output signal inversely to the adjustment of the input amplifier resulting in a predefined gain of the audio signal from the at least one input to the direct out output being maintained.

Abstract: Systems and methods for scaling the number of output channels that can be provided in an audio amplification system. In one embodiment, a digital pulse width modulation (PWM) amplification system includes multiple four-channel PWM controller chips that are interconnected to enable synchronization and transfer of digital audio data from one chip to another. Input audio signals received by each of the channels are processed by sample rate converters to generate internal audio signals that have a predetermined sample rate and format. Each of the channels is synchronized so that the internal audio signal of each channel can be processed and output by any of the other channels. The PWM controller chips are connected by a high-speed interconnect that enables the transfer of data between them. Each input audio signal can be mapped to any of the outputs and can be mixed with other input signals.

Abstract: A voltage supply circuit includes a power supply booster, an amplifier operating with a voltage generated by the power supply booster as a power supply voltage and supplying a bias voltage to a sensor, and an output voltage setting part including a feedback resistor for the amplifier. The feedback resistor has resistance determined according to a set value of a bias voltage of the sensor.

Abstract: A portable amplifier for use with electric guitars and other audio output sources. The amplifier comprises a housing, which houses components required for a portable amplifier, including a power source, at least one speaker and a male input plug that can be extended or retracted into the body of the housing. In one embodiment, the male input plug can be positioned in a plurality of orientations for insertion into musical instruments.

Abstract: An entertainment system comprising a base unit with a transceiver for interacting, at times, with a control unit via a communications link, and a control unit for controlling the base unit, the control unit being dockable with the base unit to establish direct electrical connection between them, and including a transceiver for interacting with the control unit via said link when undocked. The control unit is a separate aspect of the invention or system. The base unit may contain a tuner, preferably with bandless tuning capability, and may be designed to receive into a universal docking arrangement a digitally controllable auxiliary audio source such as a portable MP3 player or other device. The base unit may further provide alarm clock functionality with numerous features including a “fail-safe' volume control system and fail-safe alarm time setting capability.

Abstract: Power amplifies are provided to correspond with a plurality of speaker units constituting a speaker array. Driving signals from the power amplifies are supplied to one terminals of the speaker units, and other terminals are connected a common line. Inverters are provided at preceding stages of the power amplifies such that the driving signals supplied to the speaker units being arranged adjacently have an opposite phase respectively. Since a correlation between the driving signals of the adjacent speaker units is high, a current flowing through the common line can be very reduced. An LED display panel can be driven by the similar method.

Abstract: The present invention relates to an apparatus and method for redeeming otherwise closed and concealed information contained in audio signals. This includes both the primary reference signal, and a plurality of redundant duplicate signals, substantially identical in all respects to the primary reference signal except in relation to magnitude and phase, for the purpose of unfolding, or opening the audio signal content into layers that result in an omni-directional acoustic signal, representing the sound as it would behave in nature. The audio reproduction system uses an in-phase circuit and a separate phase layering technique circuit to drive independent multiple mixed channels, to produce an open, substantially complete sound from a discrete audio signal, for the purpose of enabling a substantially complete audio signal to be formed, or to transform existing incomplete audio signals into a substantially complete audio signal.

Abstract: Systems and method to compress digital video based on human factors expressed as a desirability score are provided. A particular method includes passing a digital input signal through a pulse-width modulator and passing an output of the pulse-width modulator through a power switching device. An output of the power switching device has a plurality of pulses. The method includes receiving the output of the power switching device at a first input of a comparator and receiving a reference voltage at a second input of the comparator. The method includes determining a net signal based on an output of the comparator and determining a timing error signal based on the net signal and the digital input signal. The method also includes adjusting the digital input signal to compensate for harmonic distortion based at least in part on the timing error signal.

Abstract: An audio processing apparatus includes an amplification unit to receive and amplify an audio signal, a power source unit to provide power source to the amplification unit, and a signal processing unit to adjust the power source level provided to the amplification unit based on audio signal level and power source level. Accordingly, high-quality audio may be reproduced.

Abstract: An audio output device is provided and includes a power source, a controller, a signal generating circuit, and a first amplifier. The power source provides a supply voltage signal. The controller receives the supply voltage signal. The controller further compares the supply voltage signal with a threshold voltage signal and generates a control signal according to the comparison result. The signal generating circuit generates a first analog signal. The first amplifier receives the first analog signal and generates a first amplified signal according to the control signal.

Abstract: An apparatus for effecting sound stage expansion in an audio system presenting two sound channels includes: (a) A first signal source coupled for providing at least one first signal representing a first sound channel to at least one first input locus of a first amplifying unit. The first amplifying unit participates in presenting the first sound channel. (b) A second signal source coupled for providing at least one second signal representing a second sound channel to at least one second input locus of a second amplifying unit. The second amplifying unit participates in presenting the second sound channel. (c) At least one first filter unit coupling the first signal source with at least one of the at least one second input locus. (d) At least one second filter unit coupling the second signal source with at least one of the at least one first input locus.

Abstract: A system includes multiple speakers arranged in a speaker array configuration. The system also includes one or more filters configured to filter audio signals and generate filtered audio signals. The one or more filters are configured to operate using filter coefficients associated with a desired beam pattern to be produced by the multiple speakers. The system further includes at least one amplifier configured to amplify the filtered audio signals and provide the amplified filtered audio signals to the speakers. The one or more filters reside within or are coupled to the at least one amplifier. The system may further include a controller configured to modify at least one of the filter coefficients based on a change in the speaker configuration. The filters may operate independently of a centralized processor, and a centralized processor may not even be required to provide electronic beam forming.

Abstract: Ground skimming output stages that are designed to drive wideband signals with the ability to provide a high quality output signal all the way to the low supply rail are provided. In accordance with an embodiment of the present invention, the output stage of the present invention includes a translinear current controller, an output transistor and a current mirror. While not limited thereto, embodiments of the present invention only require a single positive power supply, consistent with the recent trend toward integrated circuits that only require a single low voltage power supply.

Abstract: An intelligent notification appliance circuit has a controller and one or more addressable notification appliances coupled with a single pair of wires. The controller outputs integrated power, audio and control signals, and transmits the integrated signals to the one or more addressable notification appliances. Thus, the one or more addressable notification appliances are powered, operated, controlled, and monitored using the intelligent notification appliance circuit. When the intelligent notification appliance circuit is implemented in a fire and/or mass notification system, that system is able to provide integrated audio signals, power signals and control signals over a single pair of wires. The integrated audio signals may carry data indicative of live or recorded music and/or voice messages, such as: mass notification messages, general page, voice evacuation, and the like.

Abstract: An apparatus is provided for attenuating electrical signals in the signal path of an electronic audio frequency amplifier for amplifying signals from musical instruments. In accordance with a preferred embodiment, the apparatus is configured to be coupled to the amplifier in more than one arrangement and the apparatus exhibits different attenuation characteristics depending on which arrangement is used to couple the apparatus to the amplifier.

Abstract: The present invention provides a class D amplifier and method for driving a tri-wired stereo amplifier. Additionally, the class D amplifier includes a first filter, a second filter, a processor, a 2D-quantitizer, a signal generator, and a logic circuit. The class D amplifier and method of the invention can reduce cost of production and increase processing efficiency. More particularly, the class D amplifier and method of the invention are processed in an optimal feedback mode, so as to reduce the reciprocal effect between the two channels, and avoid mismatch of the two amplifiers.

Abstract: An audio host device has a connector having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a first cold input, a second cold input, and hot input. The first cold input is coupled to an output of the speaker amplifier, while the second cold input is coupled a sense point for the reference contact. The hot input is coupled to the microphone contact. Other embodiments are also described and claimed.

Abstract: The present invention relates to an audio amplification circuit with first and second signal channels which generate first and second digital audio signals with different signal amplifications from a common audio input signal and a method of amplifying a common audio input signal with different signal amplifications to provide first and second digital audio signals with different amplification. The audio amplification circuit is particularly well-adapted for cooperating with an external or integral audio signal controller configured for receipt and processing of the first and second digital audio signals.

Abstract: An edge (29) for supporting a diaphragm assembly (100) with respect to a frame (26) is bonded to the frame (26) along the outer periphery thereof and joined to a diaphragm (27) in a position more peripherally inward than a voice coil (28) along the inner periphery thereof. The edge (29) partly overlaps diaphragm (27). This structure allows downsizing of the speaker, without reducing the sizes of a permanent magnet (21) and the edge (29).

Abstract: A high efficiency audio amplifier is disclosed. The high efficiency audio amplifier includes an input end for receiving an input audio signal, an output end for outputting an output audio signal, a signal generator coupled to the input end for determining a frequency of an oscillating signal according to the distribution of the input audio signal and a reference voltage, and generating the oscillating signal accordingly, a waveform transformer coupled to the input end and the signal generator for comparing the input audio signal with the oscillating signal to generate a pulse width modulation (PWM) signal, a pre-drive circuit for generating a pre-drive signal according to the PWM signal, an output stage coupled to the pre-drive circuit for generating an output signal, and a filter coupled to the output stage for filtering the output signal to generate the output audio signal to the output end.

Abstract: A method and apparatus to provide an automatic alarm for a cell phone. A user of the cell phone can set a safe zone, which is a geographic area centered at a particular location with a circular boundary of a preset radius. If the cell phone is removed outside of this radius, the cell phone is presumably stolen, and thus an audible alarm on the cell phone can be triggered.

Abstract: A travel carrier suitable for use in transporting a live animal via a mode of transportation, comprises an enclosure of suitable size and shape for a live animal; a power source; a video camera connected to the power source and arranged in the enclosure for capturing a video image of the animal in the enclosure; and an RF transmitter. The transmitter, which is operatively connected to the video camera, transmits a signal representing a video image of the animal to a remote receiver. The carrier may also comprise a GPS unit disposed on or in the enclosure, which is operatively connected to a transmitter, for transmitting a signal representing the location of the carrier to the remote receiver.

Abstract: A class H amplifier circuit includes a Buck converter 20 and a charge pump 30 which are used to generate voltages which are used in turn to power an output driver 10. A feedback path 36 controls the loop. The circuit is particularly suitable as a high efficiency circuit for driving headphones or loudspeakers.

Abstract: An audio system comprises a first enclosure for housing a first audio component and a second enclosure for housing a second audio component. The first enclosure includes a surface having a plurality of first structures, the first structures comprising one selected from a group consisting of a plurality of protrusions and a plurality of receptacles. The second enclosure includes a surface having a plurality of second structures, the second structures comprising the other one from the group consisting of the plurality of protrusions and the plurality of receptacles. The protrusions are configured to be inserted into the receptacles along a first direction such that the first enclosure is maintained in a first position relative to the second enclosure in the presence of a shear force that is applied in a direction that is perpendicular to the first direction.

Abstract: An audio processing circuit is provided, receiving a microphone signal from a microphone to output a differential signal. A preamplifier receives the microphone signal to output a first preamplified voltage and a second preamplified voltage. A gain stage receives the first preamplified voltage and the second preamplified voltage to output the differential signal comprising a first differential output and a second differential output. In the preamplifier, a first operational amplifier is provided. A first voltage controlled current source is controlled by the output end of the first operational amplifier to provide a first current. A first transistor has a gate coupled to a ground voltage supply, a source coupled to the first voltage controlled current source for receiving the first current, and a drain coupled to a voltage ground. Likewise, a second voltage controlled current source and a second transistor are presented symmetrically to render the differential output.

Abstract: An operation-mode conversion apparatus for an image display compound device includes a power-state detector which detects a power state of the compound device, an operation-mode determination unit which determines a present operation mode of the compound device, and an operation-mode controller which converts the operation mode of the compound device based on the power state, the present operation mode, and whether one of an optical storage medium and a movable memory is detected by the compound device, in response to a user input signal, regardless of the preset operation mode.

Abstract: A portable electrical appliance comprises an audio signal source, a power supply module having a housing external to the portable electrical appliance for providing power to the electronic appliance having, a power converter for providing DC power to at least the portable electrical appliance, a speaker for generating sound and audio processing means for manipulating audio signals from the audio signal source, wherein the power converter, audio processing means and speaker are mounted within the housing, and communication means for coupling the audio signal to the processing means. The communication means is able to be wireless or wired.

Abstract: A feed-forward amplifier includes a main amplifier having input signals and amplified output signals and an error amplifier for amplifying distortion signals to be added to the amplified output signals of the main amplifier to produce an amplifier output. A pilot tone modulation and recovery circuit modulates a pilot tone to be coupled to the input signals of the main amplifier and recovers the pilot tone from the amplifier output. The pilot tone modulation and recovery circuit includes a digital filter and a signal source. The signal source is used to both modulate the pilot tone and control the digital filter for recovering the pilot tone.

Abstract: A projector includes: a first audio input section adapted to input a first sound signal; a second audio input section adapted to input a second sound signal; a first sound amplifier section adapted to amplify the first sound signal received through the second audio input section to generate a first amplified signal; a second sound amplifier section adapted to amplify the second sound signal received through the second audio input section to generate a second amplified signal; a first audio output section adapted to output a first sound based on the first amplified signal; a second audio output section adapted to output a second sound based on the second amplified signal; and a determination section adapted to determine whether or not the first sound signal is being input.

Abstract: A loudspeaker input switch system for a truck cabin includes set of loudspeakers arranged in a perimeter arrangement, and an amplifier for amplifying signals from both a stereo player with a forward front-of-stage simulation, and a surround sound player with a front-of-stage simulation rotated 90° from the forward direction. A switching mechanism is used to selectively control the amplifier to change orientation of the front-of-stage simulation. A stereo music program can be played oriented correctly for a user driving the truck and a surround sound program can be played correctly oriented for a user turned 90° from the driving position.

Abstract: An apparatus and a method for outputting an audio signal in a portable terminal are provided. The portable terminal for outputting an audio signal includes an ear jack, a modem, and an amplifier. The ear jack connects the portable terminal with one of an earphone and an external apparatus. The modem detects whether one of the earphone and the external apparatus is connected to the ear jack. When connection of the external apparatus is detected, the amplifier high power-amplifies the audio signal and outputs the same to the external apparatus according to a control of the modem.

Abstract: In some embodiments, a subwoofer enclosure includes a substantially triangular first face, second face, third face, and fourth face, a first corner at an intersection of the first, second and third faces, a second corner at an intersection of the first, second and fourth faces, a third corner at an intersection of the first, third and fourth faces, a fourth corner at an intersection of the second, third and fourth faces, wherein an angle between the first corner and a midpoint between the third corner and the fourth corner, having the second corner as its vertex, is substantially ninety degrees, wherein an angle between the third corner and the fourth corner, having the second corner as its vertex, is substantially ninety degrees, and a subwoofer driver attached to the third face, having a free air resonant frequency less than one hundred Hertz.

Abstract: A thermal sensor at the output of a switching amplifier senses heat dissipation at the output switch. If an overheating condition is sensed, gain of the digital input signal is lowered to reduce output power of the audio output signal.

Abstract: An amplifier having at least one switch controlled by an output voltage of a hysteresis block, wherein the hysteresis block is adapted to receive an input voltage signal based on an integration of an error signal, a low threshold voltage and a high threshold voltage, and is arranged to change the output voltage from a first value to a second value when the input voltage signal is higher than the high threshold voltage and to change the output voltage from the second value to the first value when the input voltage signal is lower than the low threshold voltage, and wherein the low threshold voltage is equal to Vref??VDD and the high threshold voltage is equal to Vref+?VDD, where Vref is a common mode voltage level, ? is a non-zero constant, and VDD is a power supply voltage.

Abstract: An AC/DC power supply and platform for a military radio has been developed. The apparatus includes a base that supports at least one SINCGARS RT-1523 radio. The base is connected to an AC power supply and at least one DC power supply. The AC supply and DC power supply are configured to switch automatically to the DC power supply should the AC power supply fail. The housing of the platform is sealed from the exterior environment with gaskets.

Abstract: Addressable amplified speakers assembly, and method for addressing the same, suitable for any permanent or temporary public address paging application. Amplified speakers assembly may incorporate VHF and UHF radios to provide wireless, one-way paging from a few feet to many miles away. These speakers can be added to any existing radio system with minimal effort or cost. The need for routing signal cable is eliminated, greatly reducing installation costs. Each speaker can be programmed for individual, group, or all-page access via DTMF or 2-Tone coding (up to 8 different addresses). The volume of each speaker can also be controlled remotely.

Abstract: A two-channel amplifier with common signal including a splitter for establishing three intermediate signals on the basis of two input signals, wherein the three intermediate signals represent two channels, one of the three intermediate signals being a common signal common to both of the two channels and having a representation based on a sum of the two input signals.

Abstract: An amplifier circuit which, includes a first input for receiving a first input signal and a second input for receiving a second input signal. A first amplifier section is connected to the first input and the second input is present. The first amplifier section can combine the first signal and the second signal into a first combined signal, the first amplifier being connected to a first output, for outputting the first combined signal. A second amplifier section is connected to the first input and the second input, for combining the first signal and the second signal into a second combined signal, the second amplifier being connected to a second output, for outputting the second combined signal. A common mode section is connected to the first input and the second input, for generating a common mode signal based on a combination of the first signal and the second signal and outputting the common mode signal at a common output connected to the common mode amplifier.

Abstract: An audio power amplifier provides a virtual ground to reduce power on/off noise and a method for processing a signal in the audio power amplifier. The audio power amplifier includes a switching amplifier to amplify a small output pulse width modulation (PWM) signal so as to generate a large output PWM signal, a pulse generating unit to generate a pulse signal having the same level as that of the PWM signal level, a first low pass filter to allow the large output PWM signal amplified by the switching amplifier to be low-pass filtered so as to restore the PWM signal to an audio signal, and a second low pass filter to allow the pulse signal generated by the pulse signal generating unit to be low-pass filtered so as to convert the pulse signal into a virtual ground voltage with respect to the restored audio signal.

Abstract: A band-splitting time compensation signal processing device 2 includes a band-splitting circuit 211 for extracting, after extracting a signal of a high-frequency band component or low-frequency band component from an input signal, a signal of the low-frequency band component or high-frequency band component by subtracting the signal of the high-frequency band component or low-frequency band component from the input signal; a delay circuit 212 for delaying, for adjusting arrival time, at least one of the high-frequency band component and low-frequency band component output from the band-splitting circuit 211; and a mixing circuit 213 for combining the high-frequency band component or low-frequency band component output from the delay circuit 212 with the low-frequency band component or high-frequency band component output from the band-splitting circuit 211.

Abstract: A multi-channel power amplifier for driving a plurality of loads, each associated with a respective channel, each channel comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable by configuring switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage output by a dedicated voltage buffer of the multi-channel amplifier for driving the respective load of the channel, comprises a window comparator for monitoring the level of the input signal of the channel and producing a logic control signal for the configuring switches. Each channel has a dedicated window comparator monitoring the level of the input signal of the channel that generates a logic signal for positioning the switches that configure the output power structure of the channel in single-ended or bridge configuration.

Abstract: In an amplifier circuit of a capacitor microphone, when a too high input signal from the capacitor microphone is inputted, the levels of output signals of the amplifier circuit are limited. A first feedback capacitor of an operational amplifier is formed using a changeable capacitance type MOS capacitor element, and has a characteristic of increasing the capacitance value CAf1 according to the amplitude of an input signal generated by a capacitor increases. Therefore, CAf (=CAf1+CAF2) increases according to the amplitude of the input signal increases, and accordingly the gain of the operational amplifier decreases, thereby limiting the output signals of the operational amplifier. This realizes the appropriate limitation of the output signals of the operational amplifier, even when the amplitude of the input signal becomes too high.

Abstract: Provided is an electronic device which can prevent operation stop attributed to lowering of an electronic device operation voltage. A pre-stage of a power amplifier (24) is connected to a capacitor and a first and a second current limit circuit. A CPU (21) monitors a voltage of the capacitor and corrects a gain of the power amplifier (24) in accordance with the voltage value. Moreover, when the electronic device includes a speaker system having a plurality of channels, an audio signal reproduction mode is switched, for example, between a stereo reproduction and a monaural reproduction according to the voltage value of the capacitor.

Abstract: An amplifier circuit comprises differential amplification circuitry comprising an input stage having first and second differential inputs, and an output stage, having respective first and second amplifier components with first and second differential outputs. The first amplifier component of the output stage comprises a first power transistor operably coupled to the first differential output and driven by a first differential output of the input stage, and a third power transistor operably coupled to the first differential output of the amplifier circuit and driven by a second output of the input stage. The second amplifier component comprises a second power transistor operably coupled to the second differential output and driven by a second output of the input stage, and a fourth power transistor operably coupled to the second differential output and driven by the first output of the input stage.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.