BLDC motors
US8203296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2008 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Nov 1, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A 2-phase BLDC motor is driven by a trapezoidal waveform. For one-half of the motor rotation period T, the phase is driven by the trapezoidal waveform and for the other half-period, the coil remains undriven. An up down counter is operable to increment at a first frequency f1 and to decrement at a second frequency f2. Incrementing operation is initiated at the start of the driven period of the waveform and stopped at the start of the down slope of the waveform. Decrementing operation is initiated at the start of the down slope of the waveform and stopped at the end of the down slope. The ratio of frequencies f1:f2 is used to measure the relative duration of the slope to the driven period and is selected to mirror the desired ratio of slope duration:driven period duration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.