Other

Nanowatt Inc.

Chung-Fu Chou

The present invention generally relates to a structure and method of audio amplifier with power feedback, including a power amplifying unit, a loud-speaker, a current sensing unit, a voltage sensing unit and a multiplying unit. The power amplifying unit includes an input side and an output side, the input side inputs an audio voltage signal, and the loudspeaker is electrically connected to an output side of the power amplifying unit. The current sensing unit is electrically connected to the output side of the power amplifying unit and senses the output current of the power amplifying unit and then converts it into a current control voltage signal. The voltage sensing unit is electrically connected to the output side of the power amplifying unit, and senses the output voltage of the power amplifying unit to form an output sensing voltage signal. The multiplying unit obtains the voltage of the current control voltage multiplied by the output sensing voltage, and the output side of the multiplying unit is electrically connected to the input side of the power amplifying unit to form a closed loop power feedback structure. Accordingly, the output quality of the amplifier and loud-speaker is improved.

Structure and method of audio amplifier with power feedback

The present invention generally relates to a structure and method of audio amplifier by dynamic impedance adjustment, including a power amplifying unit, a loud-speaker, a current sensing unit and a subtraction unit. The power amplifying unit has a fixed closed loop gain, with an input side and an output side; the loud-speaker is electrically connected to the output side of the power amplifying unit; the current sensing unit senses the output current of the power amplifying unit, and the sensed output current is converted into a current control voltage signal; the subtraction unit inputs the audio voltage signal and the feedback current control voltage signal, and outputs the difference of the audio voltage signal minus the current control voltage signal, and inputs it to the input side of the power amplifying unit. The output sound quality of the loud-speaker is improved by dynamic impedance adjustment.

Structure and method of audio amplifier by dynamic impedance adjustment

A flyback power switch structure for bridgeless rectifier includes a main transformer, a primary side circuit, a secondary side circuit, and a feedback control circuit. The main transformer includes a primary coil and a secondary coil. The primary side circuit is connected to the input AC power supply and the primary coil of main transformer, and is provided with a first switch component, a second switch component, a third switch component, and a fourth switch component. The secondary side circuit is connected to the secondary coil of said main transformer, generating an output voltage. The feedback control circuit is connected to the secondary side circuit and the first, second, third and fourth switch components of primary side circuit, comparing phase signals according to the feedback signals and the first and second terminal voltages of an input AC power supply to control the actuation of the first, second, third and fourth switch components.

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Yongkang, Taiwan

Chung-Fu Chou