Telephone ring detector circuit
US4066848A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 7, 1976 |
| Grant date | Jan 3, 1978 |
| Priority date | — |
| Expiry date | Sep 7, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/654
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telephone ring detector circuit is provided which finds particular utility in telephone answering systems. The detector circuit responds only to ring signals on the telephone line to activate the system, and it is unresponsive to dialing pulses, or other signals, that may be present on the telephone line. The detector circuit of the invention distinguishes the ring signals from the other signals on the telephone line by counting the number of pulses present on the telephone line for the various signals and providing a ring detect output only when the number of pulses is in excess, for example, of the pulses which form the trains of the dialing signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.