Signal compressors and expanders
US3934190A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 1974 |
| Grant date | Jan 20, 1976 |
| Priority date | — |
| Expiry date | Oct 31, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/64
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Compressors and expanders for effecting dynamic range modification are constructed by connecting reactive networks in series for voltage dividing action or in parallel for current dividing action. The output signal is derived from the voltage across or current through one of the networks which includes a series or parallel variable resistance. The variable resistance is controlled in dependence upon the voltage thereacross in the sense required to achieve compression or expansion, as the case may be. The resistance change shifts a turnover frequency of the circuit so as to exclude large amplitude components from the amplitude increase or reduction which is applied to low level components within a restricted frequency band to create the compressor or expander action.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.