Hi-Fi Audio Power Supply Noise Reduction via AC-Battery Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hi-fi audio devices are sensitive to noise from AC power-line noise, which degrades sound quality and requires additional components for noise filtration, increasing device size and economic costs, and also face system noise due to unequal current intensities for different elements.
Innovation Solution
A hi-fi audio device with a power supply unit that switches between AC and battery power based on whether it is reproducing a sound source, blocking AC power during reproduction and using battery power to minimize noise, and charging the battery when not in use, with a control unit determining the power source to supply the appropriate current to each element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AC power supply is used to provide power during sound reproduction, then the device can operate continuously with sufficient power, but noise from the AC power line degrades sound quality
Solution Approach 1:
The power supply system is segmented into multiple independent power sources: AC power supply for non-reproduction operations and battery power for sound reproduction. This segmentation allows each power source to be used in its optimal operating condition, preventing AC power line noise from degrading sound quality while maintaining continuous operation capability.
Solution Approach 2:
The power supply switching mechanism dynamically changes the power source based on the operational state. During sound reproduction, the system switches to battery power to eliminate noise; during non-reproduction operations, it switches to AC power for continuous operation. This dynamic switching resolves the contradiction between reliability and noise prevention.
2Object-affected harmful factors
If noise filter or panel board separation is used to prevent AC power line noise, then sound quality can be improved, but the device size increases and additional components are required
Solution Approach 1:
The harmful AC power source is extracted from the power supply chain during sound reproduction operations. Instead of adding noise filtering components to the AC power path, the system completely removes AC power from the audio signal path by switching to battery power, thereby eliminating noise without requiring additional filtering components.
Solution Approach 2:
The battery serves as an intermediary power source that bridges the gap between AC power availability and noise-free operation. During sound reproduction, the battery mediates by providing clean power without the noise characteristics of AC power, eliminating the need for noise filtering components.
3Device complexity
If one battery supplies power to all elements of the audio device, then the power supply structure is simple, but system noise occurs due to unequal current intensities for different elements
Solution Approach 1:
The battery power supply is segmented into multiple independent cells, with each cell connected to specific audio elements that require similar current intensities. This segmentation allows each element to receive appropriate current intensity without causing system noise, while maintaining a relatively simple battery-based power supply structure.
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
This solution effectively reduces noise interference from AC power-line noise and internal system noise by selectively using battery power during sound reproduction and AC power for charging, maintaining high-quality sound output while optimizing current usage.
Implementation Method 1
an alternating current (AC) power supply unit configured to rectify alternating current supplied from an external power supply into first direct current
Implementation Method 2
a battery unit configured to supply second direct current to the operation unit
Data Source
AI summary
A hi-fi audio device for reproducing and outputting a hi-fi sound source, the hi-fi audio device including: an operation unit configured to operate the hi-fi audio device; and a power supply unit comprising: an alternating current (AC) power supply unit configured to rectify alternating current supplied from an external power supply into first direct current and supply the first direct current to the operation unit; and a battery unit configured to supply second direct current to the operation unit, wherein the operation unit receives the first direct current and drives the hi-fi audio device when the operation does not reproduce a sound source, and receives the second direct current and drives the hi-fi audio device while the operation unit reproduces the sound source, and while the sound source is reproduced, the supply of the first direct current to the operation unit is blocked.