Dual-slope current battery-feed circuit
US6301358A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1998 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | May 29, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A dual-supply line-interface circuit (100) uses a -48V power supply (V.sub.BAT1) to drive long subscriber loops (120) and uses a -28V power supply (V.sub.BAT2) to drive short subscriber loops. For intermediate-length loops, a dual-slope current-feed profile (FIG. 4) is employed to limit the line-circuit's power dissipation. The line-interface circuit operates in an apparent constant-current mode, generating about 40 mA of differential line current using the low power supply, up to a threshold line voltage of about 25V, which is equal to the low power supply voltage minus required overhead. For longer loops, the line-interface circuit switches to a second constant-current mode, generating about 22 mA of differential current using the high power supply, which maintains the loop current constant until it drops to the 48V resistive-feed value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.