Telephone ringing generators
US4015091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1975 |
| Grant date | Mar 29, 1977 |
| Priority date | — |
| Expiry date | Dec 5, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A single channel carrier system for telephone service is disclosed including a remote terminal having a battery charger for charging a battery during idle periods to power the remote carrier electronics. The remote electronics include a ringing generator and supervisory circuits to implement normal telephone supervision over the carrier channel. The ringing generator is a DC-to-DC converter for stepping the battery voltage up to ringing voltage level. This high unipolar ringing voltage is then interrupted at a 20 Hz rate during the ringing portion of the ringing cycle. Simple diodes serve to isolate the unipolar ringing signals from other portions of the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.