360 Degree linear variable phase transformer
US4297698A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1977 |
| Grant date | Oct 27, 1981 |
| Priority date | — |
| Expiry date | Nov 2, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2291
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A linear variable phase transformer directly converts mechanical displacement information to phase information capable of varying fully over preferably more than a 120.degree. period of a typical AC cycle and up to 360.degree. or more phase variation. Three or more linearly arranged primary windings produce respective AC magnetic fluxes that are phase separated by equal amounts over such full period. A core, which is movably positioned relative to the primary windings, receives and/or combines one or more of such fluxes to produce an output flux that induces in a secondary winding an output AC electrical signal having a phase corresponding to that of the output flux and, thus, the positional relationship of the core and the primary windings. The output AC electrical signal is a time-based signal that can be utilized directly in analog applications or readily demodulated for digital use. The use of anti-fringing primary windings to reduce fringe effects and an elongated core that has an apparent or effective length shorter than its actual physical length also are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.