Audio amplifier
US4369412A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 17, 1980 |
| Grant date | Jan 18, 1983 |
| Priority date | — |
| Expiry date | Oct 17, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An audio amplifier having an auxiliary terminal for connection of a feedback line to the grounded terminal of a loudspeaker and including a circuit for protection against voltage overload on the amplifier and loudspeaker if the auxiliary terminal is inadvertently connected to the ungrounded terminal of the loudspeaker, or in case of malfunction of the feedback circuit. The protection circuit includes a signal generator activated by the closing of a power switch for circuiting a check signal through the terminals of the loudspeaker to the auxiliary terminal and a controller sensitive to the voltage at the auxiliary terminal for controlling a switch for muting the output of the amplifier if the voltage at the auxiliary terminal exceed a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.