Driving circuit for brushless DC motors
US4633150A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Dec 3, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A driving circuit for a brushless DC motor having a small amount of torque ripple comprises a magnetic pole position detecting circuit for detecting positions of magnetic poles of a rotor magnet and delivering polyphase signals indicating the positions, a rectifier adder circuit for producing a sum of positive or negative portions of the polyphase signals from the magnetic pole position detecting circuit, a first error amplifier for adjusting a gain of the magnetic pole position detecting circuit to make an output signal of the rectifier adder circuit to be proportional to an instruction signal, a power supply circuit for supplying currents to armature coils in response to the polyphase signals, a modulating signal producing circuit for producing a modulating signal synchronized with the rotation of the motor, and a second error amplifier for adjusting a gain of the power supply circuit to make the currents supplied to the armature coils to be proportional to the modulating signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.