Loop current detector with threshold setting impedance
US4454477A · kind A · utility
12Cited by
8References
12Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1982 |
| Grant date | Jun 12, 1984 |
| Priority date | — |
| Expiry date | Apr 28, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q3/00
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a loop circuit closure detector, a circuit which connects a voltage comparator to the loop circuit is biased so that the comparator indicates loop circuit closure at a predetermined minimum non-zero value of loop current. Comparator inputs are both coupled to supply voltage connections by approximately equal-attenuation paths and are both coupled to said loop circuit by approximately equal-attenuation paths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.