System for communicating through partitions
US5384838A · kind A · utility
11Cited by
13References
13Claims
0Family size
Inventor
Key dates
| Filing date | May 19, 1992 |
| Grant date | Jan 24, 1995 |
| Priority date | — |
| Expiry date | May 19, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/025
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An intercommunication system for transmitting signals through a door, and having piezo transducer devices mountable on each side of the door, a matrix of analog switches connecting the piezo transducer devices to the input and output of a bridge amplifier, and a TALK switching device which controls which piezo transducer device is connected to the bridge amplifier through the analog switches as a speaker or as a microphone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.