Automatic loudness control circuit
US4982435A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1988 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Apr 12, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G5/165
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic loudness control circuit for automatically controlling the magnitude of boosting of the low-frequency component of an audio signal in accordance with the output signal level of a power amplifier for driving a loud-speaker. The low-frequency component of the output signal from an audio signal source is boosted by a low frequency boosting circuit to prepare a low-frequency boost signal, which is then added to the output signal of the source, and the resulting signal is fed to the power amplifier. The magnitude of boosting by the boosting circuit is controlled according to the output level of the power amplifier and is therefore increased as the output level lowers. Consequently, the circuit assures optimum loudness control at all times, permitting the loudspeaker to produce dynamic sounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.