摘要:
An apparatus includes a computer enclosure with a first fan, a second fan, a fan controller, and an input for receiving a signal from a microphone indicating an amount of noise at a target location. The apparatus further includes a first actuator coupled to the first fan for adjusting an axial position of the first fan, wherein the controller controls the operation of the first actuator to position the first fan to reduce the noise indicated by the signal from the microphone with the first and second fans in operation. The microphone senses sound pressure and the controller automatically adjusts a position of one or more fans using an actuator to change the distance from the fan to the microphone, which may be co-located with a user, to provide destructive interference at the location of the microphone.
摘要:
An electronic device includes an enclosure for the electronic device and a duct extending from an interior to an exterior of the enclosure to exhaust airflow from the enclosure. The electronic device further includes an active noise control mechanism. The active noise control mechanism includes an internal sensor, an external sensor, and an acoustic wave generator. The internal sensor is arranged within the enclosure to sense a noise and generate an internal sensor output, and the external sensor is arranged outside of the enclosure to detect sounds and generate an external sensor output. Based on the internal sensor output and the external sensor output, the acoustic wave generator generates an acoustic wave within the duct to reduce the noise.
摘要:
Some demonstrative embodiments include a muffled rack configured to maintain at least one electronic device, wherein the electronic device has an inlet to receive air for cooling the electronic device and an outlet to discharge the air. The muffled rack may be configured to muffle noise emanating from within the rack through an air inlet and/or an air outlet of the rack. Other embodiments are described and claimed.
摘要:
A chassis with noise cancellation function which performs active noise cancellation in a first location for cancelling a noise generated in the chassis includes a sound receiving circuit receiving a surrounding sound in a second location, a memory circuit storing noise cancellation sound data and the surrounding sound that are associated with each other, a controller selecting the noise cancellation sound data corresponding to the surrounding sound received by the sound receiving circuit from the memory circuit and generating a noise cancellation signal based on the selected noise cancellation sound data and a sound output unit outputting a noise cancellation sound in said first location based on the noise cancellation signal to perform the active noise cancellation.
摘要:
A system may include a memory configured to store an attenuation waveform and control logic. The control logic is configured to receive a synchronizing signal indicative of an operating characteristic of a noise source. In response to a value of a characteristic (e.g., frequency) of the synchronizing signal, the control logic is configured to output the attenuation waveform from the memory if the attenuation waveform is associated with that value of the characteristic of the synchronizing signal. An attenuating noise generated dependent on the attenuation waveform attenuates a noise generated by the noise source.
摘要:
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.
摘要:
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.
摘要:
A method includes sensing sound pressure at a specified location, and a controller automatically adjusting a position of one or more fans among a plurality of fans to reduce the sound pressure sensed at the specified location. The position of the one or more fans may, for example, be adjusted using an actuator to change the distance from the fan and the specified location, which may be a location of a user. Optionally, the method may further include the controller automatically adjusting a speed of one or more fans among the plurality of fans to reduce the sound pressure sensed at the specified location. The position and speed of one or more fans may be adjusted to provide destructive interference at the specified location.
摘要:
A fan active noise self-lowering system includes a fan, a push assembly, at least one pickup unit and a digital signal processing unit. The pickup unit serves to capture the noise made by the fan to generate a noise input signal and transmit the noise input signal to the digital signal processing unit. The digital signal processing unit receives the noise input signal and processes the noise input signal to output a control signal for controlling the push winding assembly to operate so as to push the fan impeller of the fan to move up and down. Accordingly, the fan impeller will generate a reverse sonic wave to offset the noise.
摘要:
In a fan noise canceling system, a feedforward signal generated when a fan speed change occurs and a feedback signal read by a sensor are sent to a signal amplifying unit for signal amplification, and the amplified signals are then sent to a signal converting unit for converting into a digital signal. A hybrid controller receives and corrects the digital signals sent thereto, and conducts rapid convergence algorithm to derive a reverse digital signal. The reverse digital signal is sent back to the signal converting unit for converting into a reverse analog signal, which is then sent to the signal amplifying unit for power amplification and generating a control signal to drive a loudspeaker to produce a reverse acoustic wave, which cancels out wave of fan noise to effectively reduce fan noise without adversely affecting the heat dissipation effect of the fan.