Circuit and method for controlling brushless DC motor
US7202617B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2004 |
| Grant date | Apr 10, 2007 |
| Priority date | — |
| Expiry date | Apr 12, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/182
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for controlling a brushless permanent magnet motor is provided. The circuit comprises windings, each of the windings having a first end connected at a common node and each of the windings having a second end connectable directly to supply voltages by switches, the second end connected to an upper supply voltage or connected to a lower supply voltage or disconnected from the supply voltages; blocking circuitry connectable with the second ends, the blocking circuitry producing a blocked voltage; a comparator receiving the blocked voltage on one input and a reference voltage on another input, the comparator result indicating polarity of a back emf voltage in the associated winding; and a latch providing control signals for the circuit, an input of the latch enabled by an enable signal, an output of the latch comprising a back emf voltage detection signal. The blocking circuitry and the comparator are duplicated for each of the windings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.