Drive circuit for brushless direct-current motors
US4473782A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1983 |
| Grant date | Sep 25, 1984 |
| Priority date | — |
| Expiry date | Jan 26, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2017/0806
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit for brushless direct-current motors having a cylinder-like air gap between a permanent magnetic inner or outer rotor and a stator, the stator windings being connected to a supply direct-current source in series with a respective feed transistor. The current flux depends on position signals from a semiconductor control element determining the rotor position, in particular a Hall IC, and on the switching state of a semiconductor switch responding to blocking of the rotor and serving as blocking protection for the stator windings. In order to avoid a thermal overload of the stator windings and of the semiconductor elements contained in the circuit, the semiconductor switch provided as the blocking protection is a transistor. The emitter/collector path of the blocking protection transistor is in series with the stator windings and the feed transistors associated with each of these stator windings, and the base of the blocking protection transistor receives an inductive voltage generated in the stator windings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.