Field weakening circuits for electric motors
US4250437A · kind A · utility
9Cited by
3References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Apr 17, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/921
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A field weakening circuit for an electric motor comprises a switching circuit the impedance of which is variable connected in parallel with a field winding of the motor. The switching circuit impedance is variable in dependence upon motor speed and current, either continuously or in a plurality of discrete steps, to control the current through the field winding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.