Interface circuit with flux cancelling transformer circuit
US4414435A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1982 |
| Grant date | Nov 8, 1983 |
| Priority date | — |
| Expiry date | Apr 22, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/003
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A circuit for interfacing a subscriber loop to subscriber terminal apparatus is provided with a transformer having a split primary winding, a secondary winding and a balance winding. A constant current source is connected to the balance winding to cause a predetermined amount of current to flow therethrough. A current sink circuit is connected serially with the primary winding for regulating the direct current flowing therethrough to an amount proportional to that flowing through the balance winding whereby the DC flux generated by the current flowing through the primary winding substantially cancels the DC flux generated by the current flowing through the balance winding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.