Active Noise Cancellation for Micro Device Fan Cooling

Solution Overview

Problem

Micro devices face challenges in thermal management due to high fan noise, which limits cooling output and requires noise reduction to enhance fan efficiency and operator alertness for system events.

Innovation Solution

A noise reduction system is integrated into micro devices, comprising a reference microphone to detect fan noise, a controller to generate a masking sound signal, and a speaker to produce a masking sound, thereby reducing fan noise and allowing increased cooling output. Additionally, an audio system generates verbal warning messages for system events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fan speed is increased to improve cooling output, then thermal management performance is improved, but fan noise increases

Engineering Contradiction:

Improvecooling outputVSAvoidfan noise

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful fan noise into a beneficial signal by using the noise-producing component as an acoustic reference for active noise cancellation. The controller generates an anti-noise signal based on the detected fan noise, transforming the harmful acoustic interference into a useful reference for cancellation algorithm.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a microphone as an intermediary device to detect fan noise and a speaker as an intermediary to generate anti-noise. These intermediary components mediate between the noise source and the user, enabling active noise cancellation without directly modifying the fan itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If fan noise is reduced by lowering fan speed, then noise level is reduced, but cooling output is limited

Engineering Contradiction:

Improvefan noiseVSAvoidcooling output

Core Design Contradiction:

Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent converts the harmful fan noise into a beneficial signal by using the noise-producing component as an acoustic reference for active noise cancellation. The controller generates an anti-noise signal based on the detected fan noise, transforming the harmful acoustic interference into a useful reference for cancellation algorithm.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a microphone as an intermediary device to detect fan noise and a speaker as an intermediary to generate anti-noise. These intermediary components mediate between the noise source and the user, enabling active noise cancellation without directly modifying the fan itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of information

If conventional warning light is used to alert operator of system events, then device can notify operator, but warning is visible only from certain locations or distances

Engineering Contradiction:

Improvesystem event notificationVSAvoidoperator awareness

Core Design Contradiction:

Loss of informationVSEase of operation

Solution Approach 1:

The patent makes the speaker serve multiple functions: it acts as both an active noise cancellation actuator and a warning notification device. This multi-functionality eliminates the need for separate warning light components and provides omnidirectional notification capability through audio signals.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces the visual warning light system with an audio-based warning system using the speaker. This substitution allows the warning to be transmitted through sound waves that propagate in all directions, overcoming the line-of-sight limitations of visual indicators.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 noise reduction system effectively minimizes fan noise, allowing for increased fan output and improved thermal management, while the audio system ensures timely operator notification of system events, enhancing device reliability and usability.

Implementation Method 1

a reference microphone for detecting a noise from the noise producing component

Methodology Applied

Scientific EffectMicrophone transduction:

Implementation Method 2

a speaker coupled to the housing for producing a masking sound corresponding to the masking sound signal

Methodology Applied

Scientific EffectSpeaker transduction:

Implementation Method 3

Cooling fans transfer heat using forced convection

Methodology Applied

Scientific EffectForced convection: Forced Convection

Data Source

PatentUS20250069579A1Fan noise reduction

Publication Date: 2025.02.27 XILINX INC

AI summary

In one example, a micro device includes a housing; a chip package disposed in the housing; a noise producing component coupled to the housing. The micro device also includes a noise reduction system having a reference microphone for detecting a noise from the noise producing component and a controller configured to receive the noise from the reference microphone and generate a masking sound signal in response to the detected noise. A speaker is coupled to the housing for producing a masking sound corresponding to the masking sound signal, whereby the masking sound reduces the noise. In another example, the noise producing component comprises a fan.