Automatic change-over notification for a receiver
US3944930A · kind A · utility
0Cited by
4References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1974 |
| Grant date | Mar 16, 1976 |
| Priority date | — |
| Expiry date | Sep 23, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/44
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Circuits for use with a receiver which notify the operator of a receiving station by means of an audio tone when an opposite station is calling or has ceased transmission. The transition of an opposite station from its transmitting to receiving state or vice versa is detected and a specific change-over sound based upon the detector output is introduced into the principal station's receiver audio amplifier circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.