Audio Signal Clipping Circuit for Speaker Overcurrent Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electronic devices face issues with overcurrent protection circuits causing unexpected shutdowns and potential speaker damage due to large current surges, leading to interruptions in output sound and equipment failure.

Innovation Solution

Implementing a current detection circuit and processor that clip signals when a threshold is exceeded for a specified time, preventing clipping until the overcurrent protection circuit activates, thus maintaining sound quality and protecting the speaker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the overcurrent protection circuit stops power supply when a large current is detected, then speaker damage is prevented, but unexpected shutdowns occur and sound quality deteriorates

Engineering Contradiction:

Improvespeaker protectionVSAvoidcontinuous sound output

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The clipper circuit performs preliminary action by clipping the audio signal before it reaches the amplifier when overcurrent is detected. This prevents the large current from occurring in the first place, thereby protecting the speaker while avoiding shutdown and maintaining continuous sound output.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The clipper circuit acts as an intermediary between the audio signal source and the amplifier. It mediates the signal by clipping it when necessary to prevent overcurrent conditions, thus protecting the system without causing shutdowns.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the clipper circuit is activated frequently to protect against overcurrent, then speaker damage is prevented, but noise and sudden volume drops occur

Engineering Contradiction:

Improvespeaker protectionVSAvoidnoise and volume drops

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system uses feedback by continuously monitoring the current through the current detection circuit and adjusting the clipping action accordingly. The clipper is activated only when overcurrent is detected and deactivated when current returns to normal levels, preventing unnecessary clipping that would cause noise and volume drops.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The clipper circuit dynamically adjusts its operation based on real-time current conditions. It transitions between active and inactive states according to the detected current levels, ensuring protection only when necessary and maintaining normal audio output otherwise.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20250392862A1Electronic device, method, and storage medium

Publication Date: 2025.12.25 CASIO COMPUTER CO LTD

AI summary

An electronic device includes: a current detection circuit (10, 20) that detects a current supplied from an adapter; and a processor (30) that processes a signal. The processor (30): clips the signal (S110) in a case where the current equal to or larger than a first threshold from the current detection circuit (10, 20) is continuously detected for a first time (S109: Yes), and outputs a clipped clip signal (I2S).