Method and system for prevention of motor reversal
US8587230B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2011 |
| Grant date | Nov 19, 2013 |
| Priority date | — |
| Expiry date | May 9, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P3/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power tool includes a brushless DC motor housed inside a tool housing, an input unit, and a control unit. The motor includes a rotor, a stator, and at least one sensor positioned to sense a state of the rotational position of the rotor inside the stator. A control unit controls commutation of the motor through a series of power switches coupled to the power supply. The control unit receives a current sensor state from the sensor and a user-selected speed from the input unit and determines whether the motor has reversed direction using the user-selected speed and the current sensor state. The control unit disables commutation of the motor if the motor has reversed direction until a proper current sensor state is received from the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.