Arrangement for measuring electrical power
US4742296A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1986 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Oct 22, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F38/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention is an arrangement for measuring electrical power. The arrangement comprises a conductor traversed by an electrical current i and a voltage-to-current converter for transforming an electrical voltage u.sub.N into a proportional supply current i.sub.N for a Hall element. The Hall element is adapted to produce an intelligence containing output signal .+-.u.sub.H proportional to the product (.+-.i.u.sub.N) of the current i and the voltage .+-.u.sub.N. The Hall element is arranged in an air-gap of a ferromagnetic core that is excited by the current i. A voltage-to-frequency converter transforms the Hall element output voltage .+-.u.sub.H into a proportional output frequency. The voltage-to-frequency converter includes a capacitor for integration purposes and at least two signal sources. The power measuring device also includes a switch for periodically switching a signal proportional to the signal .+-.u.sub.H and for switching said signal sources to compensate for an offset voltage. Use of the arrangement permits an improvement in the ratio of the intelligence containing signal to an interference signal, which interference signal includes for example an offset volt…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.