Commutatorless DC motor drive device
US4403174A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1981 |
| Grant date | Sep 6, 1983 |
| Priority date | — |
| Expiry date | Aug 17, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A commutatorless DC motor drive device in which errors due to offset voltages of differential amplifiers used therein are eliminated to thereby cause the rotor to rotate at a stable speed. Double-balance differential amplifier circuits are arranged to receive outputs of corresponding magnetic sensitive elements, such as HALL elements, upon differential input terminals thereof and external control signals upon differential control voltage terminals thereof. The outputs from the magnetic sensitive elements are amplified with an amplification factor determined by the control signals. The control signals have an amplitude determined in accordance with the rotational speed of the rotor. Output circuits control the amount of current fed to the stator coils in accordance with differential outputs of the double-balance differential amplifier circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.