Patent ID: 6990207
Filing Date: 2006-01-24
Classification: G10K

Abstract:
1. An active noise control system for use on a vehicle for reducing undesirable noise emanating from the vehicle due to operation of the vehicle, said system comprising: a noise detector for deriving an input signal representative of the undesirable noise; an interfering wave signal generator for processing the input signal to produce an interfering wave signal for generating a noise canceling wave; a limiting amplifier having a specified output signal amplitude threshold, for outputting amplified interfering wave signal having an amplitude equal to or less than the specified output signal amplitude threshold; and an electrical acoustic converter for propagating the noise canceling wave; wherein when an output of the limiting amplifier has a frequency of less than or equal to 30 Hz, and an amplitude less than or equal to the specified output signal amplitude threshold, the limiting amplifier has a constant gain; and when the output of the limiting amplifier has a frequency less than or equal to 30 Hz and an amplitude greater than the specified output signal amplitude threshold, the limiting amplifier has a gain which is adjusted in accordance with a size of an input signal.