Three-phase brushless DC motor using two hall effect devices
US4039912A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1975 |
| Grant date | Aug 2, 1977 |
| Priority date | — |
| Expiry date | Oct 20, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A three-phase brushless DC motor has three power transistors with their collector-emitter paths connected to the respective stator windings, three switching transistors with their collector electrodes connected via respective resistors to the negative terminal of a DC voltage source and their emitter electrodes connected in common to the positive terminal of the DC voltage source via a current regulating circuit, and two Hall effect devices each having a pair of control current electrodes and a pair of Hall voltage electrodes. Sinusoidal Hall voltages generated at the Hall electrodes of the Hall effect devices are combined and divided by a voltage dividing network which provides three sinusoidal output voltages. Each of the switching transistors detects the voltage difference between the output voltages. Switching occurs recyclically from one switching transistor to another in response to the output voltage which is higher than any other two output voltages. The base electrodes of the power transistors are connected to the collector electrodes of the switching transistors to provide stator currents in response to the successive switching operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.