Drive circuit for brushless DC motors
US4710684A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1984 |
| Grant date | Dec 1, 1987 |
| Priority date | — |
| Expiry date | Oct 12, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit for a brushless DC motor capable of generating a torque in the acceleration and deceleration directions, respectively, and effective when used in a portable device such as an electronic still picture camera. In the drive circuit, a power amplifier having an output stage composed of a pair of complementarily connected tansistors is connected to each end of each of the stator coils. Thus, the drive circuit controls the input potentials of the power amplifiers so as to produce a potential difference across the terminals of each of the stator coils and thereby control the magnitude and direction of current flow through the stator coils. Also, all the transistors of the power amplifier output stages are cut off to prevent the flow of current through the stator coils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.