Automatic meter reading system with malfunction protection
US5025470A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1989 |
| Grant date | Jun 18, 1991 |
| Priority date | — |
| Expiry date | Sep 8, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/002
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An output metering pulse signal is developed by measuring impedances at input terminals which are connected through lead wires to a metering unit shifted between low impedance and high impedance states while output malfunction signals are developed in response to open and shorted conditions of the lead wires, each open or shorted condition malfunction signal being developed by sensing the magnitude of the voltage at an input terminal during periodic brief applications of a strobe voltage to the input terminal through an impedance. Such output metering pulse and malfunction signals are developed in each of a plurality of automatic meter readers and are stored in the automatic meter for subsequent transmission over telephone lines to a utility control center.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.