Variable gain electronic current transformer
US3995210A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1975 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | Jun 11, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A variable gain electronic current transformer for detecting the current flow into a power consuming system. An operational amplifier amplifies the detected current and the output of the operational amplifier is converted into a magnetic flux field which is directed onto one surface of a Hall effect element. A variable current source supplies current to a second orthogonal surface of the Hall effect element to thereby generate an output voltage which is directly proportional to the product of the output of the operational amplifier and the variable current source. This output voltage from the Hall effect element is coupled back to the input of the operational amplifier. A second Hall effect element is positioned in the flux field generated at the output of the operational amplifier and in addition has a second variable current source coupled to one surface thereof so that the output of the second Hall effect element is a voltage which is proportional to the product of the output of the operational amplifier and the second variable current source. Accordingly, the output voltage of the second Hall effect element is directly proportional to the product of the detected current and the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.