Active noise control
US4876722A · kind A · utility
36Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 13, 1988 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | May 13, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/509
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An active noise control system for reducing the amount of noise propagated along a duct comprises a microphone mounted in the wall of the duct for detecting the noise, and an active antiphase noise source, such as a loudspeaker, which is mounted substantially in the center of the cross-section of the duct. A control circuit coupled between the microphone and the antiphase noise source includes an integrator having a specific transfer function, which improves the loop gain of the microphone/source loop at low frequencies, and secures stability by altering the phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.