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US 4,878,188 AGranted
Selective active cancellation system for repetitive phenomena
AssigneeNoise Cancellation Tech
InventorEldon Ziegler, Jr.
Life of this patent
Estimating the term…
Abstract
A cancellation system including a processor having single adaptive filters adapting its filtering characteristic as a function of a phenomena signal and phenomena timing signal and a phase circuit to maintain the adapting of the filtering characteristics within 90 degrees phase of the phenomena signal. The phase circuit has the capability to measure the delays of the processor and the environment.
Claims9
Repetitive phenomena cancellation controller comprising:
- phenomena input means for providing a phenomena signal representing a Phenomena to be cancelled;
- timing input means for providing a timing signal representative of a repetition rate of said phenomena;
- processor means, having inputs for said phenomena signal and said timing signal, for generating a cancellation signal to substantially eliminate said phenomena;
- output means connected to said processor means for providing a cancellation phenomena as a function of said cancellation signal;
- adaptive filter means, in said processor means, for generating said cancellation signal by adapting the filter means filtering characteristics as a function of said phenomena signal and timing signal;
- and
- phase means, in said processor means, for maintaining said adapting of said filtering characteristic within a 90.degree. phase of said phenomena signal.
4 more elements
Dependencies are inferred from the claim text.