Cooling Fan Phase Control for Computer Noise Cancellation
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Solution Overview
Problem
Cooling fans in electronic devices such as PCs and laptops generate significant noise, which is not effectively addressed by existing noise cancellation technologies, impacting the performance of active noise cancellation (ANC).
Innovation Solution
A fan control system that includes a main microphone, control circuitry, and fan controllers to calculate and adjust frequency and phase settings for cooling fans, generating square waves and modulation signals to synchronize fan speeds and reduce total acoustic noise power picked up by the microphone, thereby improving ANC performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling fans are used to dissipate heat in electronic products, then heat dissipation performance is improved, but noise level increases
Solution Approach 1:
The patent combines multiple cooling fans into a synchronized system where their rotational speeds and phases are coordinated. By merging the control of multiple fans and making them operate in unison with optimized phase relationships, the system achieves better noise cancellation while maintaining heat dissipation performance.
Solution Approach 2:
The patent dynamically adjusts rotational speed, frequency, and phase parameters of the cooling fans based on real-time noise feedback from microphones. The control circuitry continuously optimizes these parameters to minimize noise while maintaining adequate cooling, transforming fixed-parameter fan operation into adaptive parameter control.
2Object-generated harmful factors
If traditional noise cancellation methods are applied to fan noise, then some noise reduction is achieved, but performance is insufficient for effective noise cancellation
Solution Approach 1:
The patent implements a feedback mechanism where microphones capture fan noise, and the control circuitry analyzes this noise to adjust fan operational parameters in real-time. This closed-loop feedback system continuously optimizes noise cancellation by adapting fan speed and phase based on actual noise measurements, significantly improving ANC reliability.
Solution Approach 2:
The patent transitions from static fan control to dynamic control where rotational speed and phase relationships are continuously adjusted based on real-time conditions. The system adaptively changes operational parameters to maintain optimal noise cancellation performance under varying load and environmental conditions.
Data Source
AI summary
A fan control system applied to N fans inside a computer system is disclosed, comprising: a main microphone, a control circuitry, a wave generation circuitry and a number N of fan controllers. The control circuitry calculates a basic frequency value according to a temperature inside the computer system, and continuously updates a parameter by any known optimization algorithm according to a main audio signal from the main microphone. The wave generation circuitry generates N square waves according to the basic frequency value and the parameter. The N fan controllers respectively form and transmit N modulation signals to the N fans according to the N square waves and N tachometric signals from the N fans. The parameter is one of a frequency variation and a set of phase differences, and the N square waves have the same frequency.