Emergency D.C. power supply with the emergency state being indicated by polarity reversal
US4825349A · kind A · utility
55Cited by
5References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1988 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Apr 25, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2213/1332
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
This power supply is intended, more particularly, for powering a user digital terminal from a remote terminal in an integrated service digital telephone network. It comprises a main D.C. electricity power source (10) provided with a protection device (11) causing its output to go to a high impedance state in the absence of a voltage across its terminals, and an auxiliary D.C. electricity power source (20) connected in parallel and in opposition with the main source (10) and provided with a current limiting device (20) which is normally tripped by the additional current which the main source (10) attempts to impose thereon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.