D.C. current transformer circuits
US4626777A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1984 |
| Grant date | Dec 2, 1986 |
| Priority date | — |
| Expiry date | Mar 19, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A D.C. current transformer (used for measuring D.C.) comprising a common primary winding and a pair of saturable magnetic cores on which respective secondary windings are wound and connected in opposite series in series to a source of alternating e.m.f., is provided with phase-sensitive device for determining the sense of the unknown D.C. in the primary winding. The phase sensitive device periodically senses and integrates the voltage (whose waveform is the -45.degree. to +45.degree. portion of a sine wave) across at least one of the secondary windings. The sense of the integrated waveform depends on whether said voltage is initially positive or negative, and is determined by the sense of the unknown D.C. in the primary winding. Preferably said voltage is sensed at each half cycle of said alternating e.m.f.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.