Audio Jack Impedance Recognition Circuit for Portable Terminals
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Solution Overview
Problem
Small portable terminals, due to size constraints, can only accommodate a single jack interface, making it difficult to recognize and connect multiple types of audio devices, such as headphones, earphones, and microphones, as existing techniques fail to distinguish between these devices accurately.
Innovation Solution
A portable terminal with a jack interface, converter, comparators, and a controller that converts impedance values of audio device poles into voltage values and compares them with reference voltages to recognize the type of audio device connected, allowing for optimal operation and switching of audio signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single jack interface is used in small portable terminals to maintain compact size, then the device size is reduced, but the ability to recognize and accommodate multiple types of audio devices deteriorates
Solution Approach 1:
The patent applies parameter changes by measuring impedance values (electrical parameters) of the connected audio device and converting them to voltage values for comparison. Different audio device types exhibit distinct impedance characteristics that serve as identification parameters, enabling the terminal to recognize device type through electrical parameter analysis rather than physical interface differentiation.
Solution Approach 2:
The patent replaces mechanical recognition methods (physical plug shape, pole configuration) with electrical measurement methods. Instead of relying on mechanical interface variations to distinguish device types, the system uses electrical impedance measurement and voltage comparison to identify audio devices, substituting a mechanical recognition system with an electrical sensing system.
2Measurement precision
If impedance values are converted to voltage values and compared with reference voltages to recognize audio device types, then device recognition accuracy is improved, but circuit complexity increases
Solution Approach 1:
The patent segments the recognition process into distinct functional stages: impedance measurement, voltage conversion, and comparison judgment. Each stage is handled by a dedicated circuit component (impedance measurement circuit, converter circuit, comparison circuit), allowing the complex recognition task to be divided into manageable, modular functional blocks that can be independently optimized and maintained.
Solution Approach 2:
The patent introduces voltage values as an intermediary between the raw impedance measurement and the final device type recognition. The converter circuit transforms impedance values into comparable voltage values, serving as a mediator that enables the comparison circuit to function effectively. This intermediary transformation simplifies the comparison process by providing a standardized format for evaluating different device types.
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 recognition and optimal operation of multiple audio devices connected to a single jack interface, enhancing the audio functionality of small portable terminals while maintaining their compact size and reducing user intervention and potential errors.
Implementation Method 1
a converter for converting the impedance of each of the poles that correspond to a LEFT channel, a RIGHT channel, and a MIDDLE channel of a plug of an audio device, connected to the jack interface, to a voltage value
Data Source
AI summary
A portable terminal includes a jack interface for connecting an audio device thereto, a converter for converting an impedance of each of the poles, that correspond to a LEFT, RIGHT channel, and MIDDLE channel of a plug of an audio device, connected to the jack interface, to a voltage value in order to deliver the respective voltage values, a first comparator for comparing the voltage value, converted from the impedance of the pole corresponding to the LEFT channel, a second comparator for comparing the voltage value, converted from the impedance of the pole corresponding to the RIGHT channel, a third comparator for comparing the voltage value, converted from the impedance of the pole that corresponds to the MIDDLE channel, and a controller for recognizing the type of audio device connected to the jack interface based on a combination of the comparison results supplied from the first to third comparators, respectively.