Other

Amazing Microelectronic Corporation

Princeton Technology Corporation

Ming-Hsiung Chen

Shang-Shu Chung

Tung-Sheng Ku

Ming-Chung Li

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.

Power amplifier and method for restraining power of improved power amplifier

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.

Self-oscillating audio amplifier and method for restraining the improved self-oscillating audio amplifier

An audio playback apparatus is disclosed. The audio playback apparatus processes an audio signal and provides at least one output signal to at least one speaker or an earphone connected to a phone-jack. The audio playback apparatus comprises a clock generating module, a processing module, an amplifier module, and a detecting module. The processing module is connected to the clock generating module and processes the audio signal to generate a processed signal according to a clock signal generated by the clock generating module. The amplifier module amplifies the processed signal to generate an output signal. The detecting module detects whether the earphone is plugged in the phone-jack. If the earphone is plugged in the phone-jack, the amplifier module provides the output signal to the earphone. If not, the amplifier module provides the output signal to the speaker.

Audio playback apparatus

An audio signal processing apparatus is provided. The audio signal processing apparatus comprises a clock generator, a processing module, an amplifying module and an output module. The clock generator is used for generating a clock signal. The processing module is coupled to the clock generator for processing the clock signal and generating a processing signal. The amplifying module is coupled to the processing module for amplifying the processing signal and generating an amplifying signal. The output module is coupled to the amplifying module for outputting the amplifying signal.

Audio signal processing apparatus

An audio amplifier includes a plurality of sub-audio amplifier sets, a clock source, and a speaker. When the audio amplifier is under an audio amplify mode, the plurality of sub-audio amplifier sets is operated under a synchronic operating frequency with a same clock signal generated by the clock source. When the audio amplifier is under a self-oscillation mode, the clock signal is isolated from being input to the plurality of sub-audio amplifier sets. A higher distortion is prevented by repeatedly charging and discharging an oscillating capacitor of a sub-audio amplifier in a sub-audio amplifier set.

Audio amplifier capable of performing self-oscillation

A Class D amplifier capable of setting restraint power is provided, which comprises: an audio amplification unit, a pulse width modulation (PWM) unit, a first pre-drive unit, a second pre-drive unit, a first power transistor set, a second power transistor set and a power restraint unit. The power restraint unit has a comparator circuit and a power restraint circuit. The comparator circuit is configured to compare the level of first/second amplified audio signals against the level of a first reference voltage that is externally settable. When the high level of the first/second amplified audio signals is higher than the level of the first reference voltage, the comparator circuit outputs a first comparison signal and a second comparison signal to the power restraint circuit to restrain the power.

Class D amplifier capable of setting restraint power

A class D amplifier including a PWM circuit, a buffer amplifying circuit, a low-pass filter, and two current sources is provided. The PWM circuit transfers an analog signal into a PWM signal. The buffer amplifying circuit amplifies the PWM signal and generates an amplified signal. The low-pass filter will filter high frequency components out from the amplified signal and then transmit the filtered signal to a loading of the class D amplifier. The two current sources provide currents flowing into and out from a feedback node in the PWM circuit, respectively. The charging and discharging provided by the two current sources can generate a triangular signal for the PWM circuit.

Class D amplifier

The invention discloses a class-D amplifier, which is used for driving a two-terminal load according to a set of analog signals. The D-class amplifier includes a pulse-width modulation (PWM) circuit, a signal processing circuit and a driving amplifier circuit. The PWM circuit receives the set of analog signals and converts them into a set of PWM signals with identical phase. The signal processing circuit generates a set of pulse signals which are attached to the set of PWM signals respectively. The driving amplifier circuit is coupled between the signal processing circuit and the two-terminal load. The driving amplifier circuit receives and amplifies the set of PWM signals. According to the set of PWM signals, the driving amplification circuit drives the two-terminal in a filterless way.

Class-D amplifier

A Class-D power amplifier having a distortion-suppressing function includes a gain control unit, a first PWM unit, a second PWM unit, a current control unit, and a level control unit. The level control unit includes at least one D flip-flop and at least one XNOR gate. The D flip-flop has an output end coupled with the gain control unit and an R end coupled with an output end of the XNOR gate. When the Class-D power amplifier has its positive output end and negative output end respectively and simultaneously outputting a high-level signal and a low-level signal to the XNOR gate, the XNOR gate outputs the high-level signal to the D flip-flop. Then the D flip-flop outputs the high-level signal to the gain control unit as feedback for controlling the gain control unit to reduce audio gain, thereby suppressing audio distortion.

Class-D power amplifier having distortion-suppressing function

In a speaker system, pulse width modulation signals are utilized for driving said speaker system, and duty cycles of both left audio channel signals and right audio channel signals of an earphone in said speaker system are modulated by said pulse width modulation signals. When the left audio channel or the right audio channel of the earphone has no inputted audio signals with the abovementioned modulated duty cycles, the speaker system may be prevented from unnecessary power consumption. Besides, audio signals from both the left audio channel and the right audio channel of the earphone and outputted from the speaker system may thus be synchronized further by both the pulse width modulation signals and a sawtooth wave source for generating said pulse width modulation signals, for reducing noise and increasing an output audio quality of the speaker system. The abovementioned speaker system is preferably utilized for a Class D amplifier.

Speaker system of utilizing pulse width modulation signals for saving idling power consumption

After coupling a first voltage source to a voltage supply circuit, a second voltage source having a same electrical level but an opposite electrical pole with said first voltage source is generated. An audio amplifier is then driven by both the first voltage source and the second voltage source, where said audio amplifier requires a pair of voltage sources having the same electrical level but opposite electrical poles to be driven. The voltage supply circuit generates the second voltage source from the first voltage source by simultaneously switching two sets of switches, where said both sets of switches have non-synchronous statuses in switching.

Audio amplifier driven by single voltage source and related voltage supply circuit

A lamp socket with a water sealing and electric leakage preventing structure, including a channel-like rubber gasket fitted into a top wire groove in a socket body to hold an electric wire and having two slots for the passing of a positive metal contact plate and a negative metal contact plate of the socket body, a rubber cover pad covered on the rubber gasket over the electric wire and compressed against the electric wire and the rubber gasket by a socket cap being fastened to the socket body to seal the periphery of the electric wire and to prevent water from passing to the contact areas between the electric wire and the positive and negative metal contact plates.

Lamp socket with a water sealing and electric leakage preventing

An electric socket in which the socket body has two outer electric wire supports transversely raised from the two opposite ends of the top wire groove thereof, and an intermediate electric wire support transversely raised from the top wire groove between the positive metal contact plate and the negative metal contact plate, the outer electric wire supports and the intermediate electric wire support having a respective transversely corrugated top edge fitting the transverse cross section of the periphery of the electric wire being mounted in the top wire groove and forced into engagement the periphery of the electric wire to stop rain water from causing an electric short circuit or current leakage.

Structure of lamp socket

A lamp socket including a rubber top water seal member and a rubber bottom water seal member respectively fastened to two opposite ends of the socket body thereof to stop rain water from passing to the inside of the body, the rubber top water seal member having a bottom mounting groove engaged with the top edge of the socket body, two plug portions fitted into two opposite ends of a transverse wire groove of the socket body to support an electrical wire in the transverse wire groove, and two pairs of wedge blocks forced into close contact with the periphery of the electrical wire at the top by a pressure block of a socket cap, which is fastened to the socket body to hold down the electrical wire, the rubber bottom water seal having an upright annular flange fitted into an annular bottom groove at the bottom end of the socket body, a plurality of upright hooks raised from the upright annular flange and hooked in respective hook hole in the socket body, and an inward annular flap forced into close contact with the periphery of the bulb installed.

Lamp socket with water seal means for X'mas tree light set

A lamp socket in which a rubber water sealing cushion is mounted in a top recess at the center of the transversely grooved top wall of the socket body and covered around the electric wire to protect the positive metal contact plate against outside water, a rubber socket is mounted inside the socket body and covered around the positive metal contact plate, having an outward flange which is pressed on the base top of the lamp bulb and circularly covered over the tip contact thereof, and a metal strip transversely suspending on the inside and forced by the tip contact of the lamp bulb into contact with the positive metal contact plate.

Growing community of inventors

Taipei, Taiwan

Ming-Hsiung Chen