Earphone Jack Detection Circuit Noise Elimination
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Solution Overview
Problem
Conventional earphone connection detecting systems in mobile devices generate noise during connection and fail to accurately detect earphones in an electrical short state.
Innovation Solution
A mobile device with a jack interface that includes a switching device, such as a dome key, which converts mechanical changes from earphone insertion into electrical signals, allowing for noise-free detection of earphone connection through a detection circuit and controller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional earphone connection detecting system uses a ground contact to check electrical contact state, then the system can detect connection, but electrical noise is generated during connection
Solution Approach 1:
The patent extracts the ground contact function from the connection detection mechanism. Instead of using ground contact to detect connection state, the system uses a dedicated detection circuit that senses electrical contact through signal lines without requiring ground contact, thereby eliminating the noise-generating ground contact operation while preserving connection detection capability
Solution Approach 2:
The patent introduces a detection circuit as an intermediary between the earphone jack plug insertion and the connection detection. This detection circuit uses a sensing signal line that can detect connection state through electrical contact without relying on ground contact, thereby mediating the detection process to avoid noise generation while maintaining detection accuracy
2Measurement precision
If a conventional earphone connection detecting system uses ground contact, then connection can be detected, but the system cannot detect earphones in an electrical short state
Solution Approach 1:
The patent removes the ground contact dependency from the detection system. By using a dedicated detection circuit with sensing signal lines, the system can independently detect connection state without relying on ground contact, enabling reliable detection even when earphones are in an electrical short state where ground contact would fail
Solution Approach 2:
The patent implements a feedback mechanism where the detection circuit continuously monitors the electrical contact state through the sensing signal line. This feedback allows the system to detect not only normal connections but also abnormal states such as electrical shorts, providing comprehensive connection status information for reliable operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate detection of earphone connection without generating noise, regardless of the earphone's electrical state, ensuring reliable audio signal output.
Implementation Method 1
a switching device, placed in the cavity, for performing a switching operation by a physical force according to the insertion of the earphone jack plug to the cavity; a detection circuit, electrically connected to the switching device, for generating an electrical change according to the switching operation of the switching device
Data Source
AI summary
A system for detecting the connection of an earphone system to a mobile device is provided. The earphone connection detecting system detects an electrical change from a mechanical change according to the insertion of the earphone jack plug of the earphone system to the jack interface of the mobile device, via a switching device electrically isolated from the earphone system, thereby identifying the connection of the earphone system to the mobile device.