Low jitter zero crossing BEMF detector and motor incorporating the same
US6094022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1999 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Jul 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/182
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A BEMF detector and method detect the BEMF of a three-phase motor using a fully differential detection system. The motor has a first coil coupled between a first coil tap and a center tap, a second coil coupled between a second coil tap and the center tap, and a third coil coupled between a third coil tap and the center tap. The BEMF detector includes a differential amplifier having first and second inputs and first and second outputs, with the first input being coupled to one of the coil taps and the second input being coupled to the center tap. The BEMF detector also includes a comparator having first and second inputs coupled respectively to the first and second outputs of the differential amplifier and an output at which a BEMF signal is produced that is related to the BEMF of the motor. The differential amplifier may be part of an anti-alias filter structured to fix to a known stable value a common mode at the outputs of the differential amplifier. The BEMF detector also may include one or more fully differential filters positioned between the differential amplifier and the comparator to reduce noise and smooth the BEMF signal output by the comparator. One of the filters can b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.