Position sensor
US5070264A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 14, 1990 |
| Grant date | Dec 3, 1991 |
| Priority date | — |
| Expiry date | Sep 14, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
DC motors without collectors require position sensors, which recognize or identify the angular position of the rotor, in order to supply a pulse for control of the current in the coil at a suitable point in time. Hall probes which, as a rule, are used as positional sensors, involve a series of disadvantages, such as for instance sensitivity to temperature and radiation. In order to avoid these disadvantages, coils with a magnetic core through which alternating current is passed are installed in the stator-rotor air gap in accordance with the invention. The rotor comprises in the axial segment opposite the coils a magnetic portion and a nonmagnetic portion. This generates a change in the voltage drop at the coil during each rotor revolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.