Method and apparatus for determining the speed of rotation of an AC motor
US5883487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1997 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jul 25, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2235/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A speed control apparatus for determining and controlling the speed of rotation of a rotor in an AC motor. The motor includes a stator having main and auxiliary windings. Main and auxiliary winding controllers control the operational input signals supplied to the main and auxiliary windings by a signal generator. A pulse generator is connected to the main winding for providing a test pulse during a speed measurement operation. The test pulse magnetizes a portion of the rotor which induces a feedback EMF signal in the auxiliary winding. A feedback sensor circuit receives the feedback signal and forwards it to a microprocessor. The microprocessor calculates the rotational speed of the rotor based on the feedback signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.