An active noise reduction exhaust fan and its line spectrum noise active control method

Abstract

This case is an active noise-reducing exhaust fan, including: fan, grille; air duct; speaker, which is composed of one or more speaker units and the rear cavity shell of the speaker; controller, which is a digital signal processing system , should have at least 3 input ends and 2 output ends, the controller is installed on the outer wall of the air duct, wherein, the input end of the speaker unit is connected to the output end of the controller; the microphone, the microphone consists of one or more microphones The unit structure, the output end of the microphone unit is connected to the input end of the controller after conditioning and adding circuit; it also includes a motor, a motor shaft; a rotary transformer, including a stator and a mover, the stator and the motor shell are fixed, and the mover and the motor are fixed. The rotating shaft of the motor is fixed; the resolver contains three sets of coils, one of which is an excitation coil, and the other two are induction coils; the input end of the excitation coil is connected to the output end of the controller, and the output end of the induction coil is respectively connected to the controller of the two inputs.

Description

technical field [0001] The invention relates to the field of electrical appliances, in particular to an exhaust fan with an active noise reduction function. Background technique [0002] Exhaust fan is also called ventilation fan, its function is to promote the circulation of indoor air, so that the indoor solvent can be quickly removed after volatilization, not only can adjust the temperature, humidity and sensory effect, but also can avoid the pollution caused by the high content of solvent in the indoor air. Explosion or poisoning incident. According to different airflow forms, exhaust fans can be divided into centrifugal type, axial flow type and cross flow type. Exhaust fans are widely used in households, public places and industrial fields. [0003] The exhaust fan is generally driven by a motor to rotate the fan blades to drive the airflow. Affected by the rotation of the motor and fan blades, the radiated noise generally has significant low-frequency periodic nois...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the deficiencies in the prior art, the purpose of the present invention is to solve the problem of high radiation noise of the current exhaust fan, and propose a new type of exhaust fan with an integrated active noise control system, which can effectively monitor the low-frequency line spectrum components of the radiation noise. In addition, a new active control method for line spectrum noise is proposed, using a resolver to synthesize the reference signal necessary for the adaptive algorithm, so that the active system has a better line spectrum control effect

Images