Rotational speed control circuit for a D.C. motor
US4274036A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1979 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Jan 19, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/91
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rotational speed control circuit for a D.C. motor includes a power transistor with its emitter-collector path connected in series with the D.C. motor and a power supply. A base current of the power transistor is controlled by an output of a differential amplifier which is supplied at its one of input terminals with a constant voltage and at the other input terminal with a voltage changing in accordance with a terminal voltage of the D.C. motor. Further the latter input terminal of the differential amplifier is given a variable bias potential by means of an adjustable mechanism. By this circuit configuration, the rotational speed of the D.C. motor can be continuously and proportionally adjusted over a wide range and once the rotational speed is set to predetermined value by the adjustable mechanism, a stable and constant speed control for the D.C. motor can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.