Stabilized brushless motor drive circuit
US3988652A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 9, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Apr 9, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless motor drive circuit including at least one hall effect element and a drive transistor circuit adapted to produce a signal to energize at least two drive coils, which coils operate to drive the brushless motor. The amplitude of the signal applied to said drive coils is determined by the current supplied to the drive transistor circuit. A control circuit is provided for controlling said supplied current in response to the speed of the motor. The control circuit includes a single transistor coupled to said drive transistor circuit, the series connection of a constant voltage produced by a voltage limiting device and a voltage representative of motor speed being coupled to the base of the transistor to bias the control transistor to maintain a constant motor speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.