Audio Output Circuit With Voltage-Sensed Current Blocking

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Solution Overview

Problem

Existing sound output circuits face issues with unnecessary current flow when a different apparatus is connected, requiring a control terminal for activating amplifiers and reference voltage, which complicates the suppression of such currents.

Innovation Solution

A sound output circuit design that includes a controller to manage the conduction state of the reference voltage output and second terminal based on the voltage of the second terminal, using a switch like a P-channel MOSFET to prevent unnecessary current flow without the need for a control terminal or activation command, and integrating the amplifier and reference voltage output without a control terminal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a control terminal and activation command are used to suppress unnecessary current, then unnecessary current flow is reduced, but device complexity increases

Engineering Contradiction:

Improveunnecessary current flowVSAvoidcontrol terminal and activation command structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The sound output circuit automatically detects the voltage level at the second terminal and independently controls the conduction state of the reference voltage output without requiring external control commands. This self-service mechanism eliminates the need for control terminals and activation commands while effectively suppressing unnecessary current flow.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The circuit uses voltage detection at the second terminal to provide feedback that automatically controls the conduction state of the reference voltage output. This feedback mechanism enables the circuit to adaptively suppress unnecessary current based on the connected apparatus without external intervention.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If the reference voltage output is always conductive, then the circuit is simple to operate, but unnecessary current flows to connected apparatus

Engineering Contradiction:

Improvecircuit operation simplicityVSAvoidunnecessary current flow

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The conduction state of the reference voltage output is dynamically adjusted based on the voltage level detected at the second terminal. The circuit automatically transitions between conductive and non-conductive states, providing both operational simplicity and energy efficiency without requiring user intervention.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The circuit autonomously determines when to conduct or block the reference voltage output based on the connected apparatus type, eliminating the need for user control while preventing unnecessary current flow.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10959030B2Sound output circuit, projector, and control method of sound output circuit

Publication Date: 2021.03.23 SEIKO EPSON CORP

AI summary

A sound output circuit includes an amplifier that amplifies a sound signal, a first terminal for external connection connected to an output terminal of the amplifier, a reference voltage output that outputs a reference voltage, a second terminal for external connection, and a controller that controls a conduction state of an output terminal of the reference voltage output and the second terminal for external connection according to a voltage of the second terminal for external connection.