Motor control circuit for accurate speed control with capacitor leakage compensation
US4829230A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Dec 18, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/934
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A slow start motor control circuit for applications wherein extremely accurate speed control is required, such as, in a centrifugal blood separator application is disclosed. In a blood separator, the degree of separation of cellular components, such as red blood cells and platelets, from the blood plasma is a function of the rotational speed of the centrifuge and the spin time. The control circuit controls the spin time and the rotational speed of the drive motor by controlling the voltage applied to the motor. The control circuit allows the drive motor to start relatively slowly to avoid cell breakage which can contaminate the plasma. After the centrifuge attains its desired operational speed, the speed of the motor is regulated and is relatively uninfluenced by ambient temperature variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.