Circuit arrangements for modifying dynamic range using variable combining techniques
US4801890A · kind A · utility
Inventor
Key dates
| Filing date | Jun 12, 1986 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | Jun 12, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G9/025
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Circuits for modifying the dynamic range of signals, particularly compressors and expanders for use in noise reduction compander systems, in which the advantages of fixed band characteristics (variable attenuation throughout all or part of the frequency band) and sliding band characteristics (variable attenuation through part of the frequency band achieved by a variable pass filter) are provided, without the disadvantages normally inherent in each characteristic. The outputs of fixed band and sliding band circuit elements variably selected by a combining means operated by a control circuit which senses signal frequencies and/or levels, the elements operating in generally the same level range and at least a partial overlapping in frequency range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.