Electronic filter circuit
US4078215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1976 |
| Grant date | Mar 7, 1978 |
| Priority date | — |
| Expiry date | Nov 26, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G5/025
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic filter circuit having controlled "Q" with variations in attenuation. A plurality of filter networks are connected in parallel between the output and the input of an amplifier in a manner such as to be capable of selectively providing negative feedback to the amplifier. Each filter network includes inductive, capacitive and resistive elements, with a potentiometer forming part of the resistance thereof. Each potentiometer is connected in series with a resistor having the same value thereas, the arm of the potentiometer being connected to its associated filter network such that the "cut" to which the potentiometer is set determines the total value of the resistance presented by the filter network in the feedback circuit. The potentiometers and associated resistors are each connected in series with each other, these series connected elements being connected in parallel between the input and the output of a unity gain amplifier. With the potentiometers in the "flat" positions, the feedback signals are zero and thus have no effect on the output of the main amplifier. Various amounts of frequency responsive attenuation are provided by various settings of selected potentiome…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.