Range extender with variable gain for coin telephone loops
US4323733A · kind A · utility
6Cited by
4References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1980 |
| Grant date | Apr 6, 1982 |
| Priority date | — |
| Expiry date | Nov 28, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M17/023
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A range extender with gain unit for coin telephone loops is disclosed. When coin control signals to be applied from a central office to the coin loop are detected, an amplifier circuit and a line feed circuit connected to the loop are disconnected thereby directly connecting the central office with the coin telephone. After coin control is completed, the amplifier and line feed circuit are reinserted into the coin loop. Coin tests and off-hook detection are aided by the use of circuits which draw current from the central office.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.