Volume control signal coupling circuit in an audio signal processing system
US4405948A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1982 |
| Grant date | Sep 20, 1983 |
| Priority date | — |
| Expiry date | Jan 26, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An arrangement for suppressing the audible effects of operating supply voltage transients developed when a sound reproducing system including a gain controlled audio amplifier is initially energized and de-energized. A control path supplies the amplifier with a gain (volume) control voltage of positive and negative senses corresponding to maximum and minimum sound volume. A first capacitor is coupled between the control path and a source of positive operating voltage from which the gain control voltage is derived. A normally non-conductive threshold conduction device and a second capacitor are coupled in series with the first capacitor between the control path and ground. The threshold device is biased to be rendered conductive for coupling positive-going supply voltage transients away from the control path via the second capacitor when the system is initially energized, thereby suppressing the audible effects of the positive transients. Negative-going supply transients developed on the control path when the system is de-energized are in a direction corresponding to minimum volume and are essentially inaudible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.