Telephone circuit controlled by a 2 wire - 4 wire transmission integrated circuit microprocessor with line current emergency supply
US4562309A · kind A · utility
2Cited by
1References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1982 |
| Grant date | Dec 31, 1985 |
| Priority date | — |
| Expiry date | Nov 15, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The telephone circuit of the invention comprises a transmission circuit short-circuited during decimal numbering by an active circuit when the handset is lifted or during the emission of a decimal numbering digit, the line current supplying, through a voltage stabilizing circuit and a voltage regulation circuit, the microprocessor controlling the telephone circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.