Method and system for increasing subscriber line interface circuit voltage during ringing
US7480378B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 2002 |
| Grant date | Jan 20, 2009 |
| Priority date | — |
| Expiry date | Apr 20, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A voltage controller increases a DC input voltage in response to a ring instruction received from a processor in a control signal. The increased voltage is converted to an AC ring signal that causes a telephone to ring. The ring signal voltage is generated at a battery high node (“VBH”) and may be routed to a SLIC before being sent to an on-hook telephone.The voltage at VBH is kept low during off-hook and other periods when a ring instruction is not present. Thus, voltages internal to an indoor device that houses the controller are kept below a predetermined safe threshold, thereby allowing the periods of high voltage to be deemed as transient. Accordingly, if the device is unearthed, or not grounded to the earth, the device may nevertheless obtain listing by a certifying and testing organization without being subjected to abnormal testing and possible failure thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.