Fan Noise Cancellation via Active Anti-Noise Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Computer systems face challenges in simultaneously achieving efficient heat dissipation and noise reduction, as faster fan speeds for better heat dissipation generate more noise, and existing solutions fail to effectively address both issues concurrently.
Innovation Solution
An electronic system incorporating a fan module, embedded controller, reference microphone, error microphone, active noise cancellation controller, and micro speaker module, which acquires and analyzes noise frequencies and spectra to generate cancellation noise signals that counteract fan-generated noise, thereby reducing noise levels while maintaining effective heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fan speed is increased to improve heat dissipation, then heat dissipation efficiency is improved, but noise level increases
Solution Approach 1:
The system applies preliminary anti-action by generating anti-noise signals that counteract the fan noise before it fully propagates. The ANC controller continuously generates cancellation signals based on predicted fan noise characteristics, creating destructive interference with the actual noise waves to reduce overall noise levels while maintaining high fan speeds for effective heat dissipation
Solution Approach 2:
The system converts the harmful fan noise into a useful signal by using the reference microphone to capture fan noise characteristics, which are then processed by the ANC controller to generate precise cancellation signals. The previously harmful noise becomes the basis for creating the anti-noise, transforming the problem into a solution that enables both high-speed operation and noise reduction
2Temperature
If conventional heat dissipation methods are used, then heat dissipation is achieved, but noise reduction capability is insufficient
Solution Approach 1:
The fan system is enhanced with multi-functionality by integrating noise cancellation capabilities into the existing heat dissipation structure. The same fan module continues to provide heat dissipation while the added ANC components (reference microphone, error microphone, ANC controller, and micro speaker) enable simultaneous noise reduction, allowing the system to perform both heat management and acoustic control functions
Solution Approach 2:
The system introduces intermediary components between the noise source and the environment. The reference microphone acts as an intermediary to capture fan noise characteristics, the ANC controller processes these signals, and the micro speaker generates anti-noise waves. These intermediaries enable the system to control noise without compromising the primary heat dissipation function
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
The system effectively cancels noise and enhances heat dissipation by adaptively adjusting noise cancellation signals to minimize error signals, addressing the dual challenges of noise reduction and heat management.
Implementation Method 1
The micro speaker module is configured to generate a cancellation noise signal according to the speaker control signal, wherein the cancellation noise signal includes a plurality of noise compensation signals which are reverse signals respectively associated with the actual single-blade fundamental frequency, the actual single-blade overtone frequency, the actual BPF fundamental frequency, the actual BPF overtone frequency and the actual wide-band noise spectrum
Data Source
AI summary
An electronic system includes a fan module, an embedded controller, a reference microphone, an error microphone, an active noise cancellation controller, and a micro speaker module. The reference microphone is configured to output a wide-band noise signal associated with the operation of the fan module. The error microphone is configured to output an error signal by detecting the noise level during the operation of the electronic system. According to the wide-band noise signal, the error signal and the fan information provided by the embedded controller, the active noise cancellation controller calculates the narrow-band noises and the wide-band noises generated by the fan module, and drives the micro speaker module accordingly for providing a noise cancellation signal. The error signal may be reduced to zero by adaptively adjusting the noise cancellation signal for canceling the noises generated during the operation of the electronic system.