Control circuit for controlling a DC supply voltage for a terminal
US8111824B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2008 |
| Grant date | Feb 7, 2012 |
| Priority date | — |
| Expiry date | Dec 8, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/005
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A control device for controlling a supply voltage which can be switched between a constant line current operation and a constant line voltage operation, wherein a line current, which consists of a direct current for supplying the terminal and of an alternating current for transmitting information, flows via a subscriber line of a terminal, comprising a sensing circuit for sensing an analogue input voltage dependent on the line current, a subtractor which, in the constant line current operation, subtracts an analogue feedback voltage dependent on an adjustable nominal direct-current value from the sensed input voltage for generating an analogue difference voltage, an analogue/digital converter for converting the generated analogue difference voltage into a digital difference voltage value, a digital low-pass filter for filtering a sequence of control error values out of the generated sequence of difference voltage values, a controller for generating a control value in dependence on the filtered-out sequence of control error values, and comprising a first digital/analogue converter which, in the constant line current operation, converts the control value in each case generated by the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.