Apparatus and method for generating rotor position signals and controlling commutation in a variable reluctance electric motor
US5783916A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 2, 1996 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Jul 2, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/089
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for generating electrical signals which are representative of the rotational position of a rotor relative to a stator and for controlling commutation in a variable reluctance electric motor includes a circuit for generating relatively small pulses of electrical current to a non-energized stator winding of the motor. As the rotor rotates relative to the stator, the inductance induced in such stator winding will vary. As a result, the magnitude of the current pulses in the stator winding will increase over time. When the magnitude of such current pulses exceeds a predetermined threshold level corresponding to a predetermined relative rotational position of the rotor, a signal is generated to cause commutation of the motor. Variations in the inductances of the stator windings are compensated for by providing maximum and minimum voltage detector and hold circuits which are responsive to the output signals from the sample and hold circuit. By generating the threshold level as a function of the maximum and minimum signals, such as by a resistive voltage divider network, compensation is made for these variations in inductance. The above functions can be accomplishe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.