Method and apparatus for preventing excessive current flow in a motor
US5721474A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1996 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Aug 7, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/903
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control circuit comprises a current command circuit generates a current command signal proportional to a selected motor speed. A comparator generates a comparator output signal proportional to the difference between the current command signal and a signal proportional to current flow in the motor. An output terminal of the comparator is operatively connected to a logic circuit which generates a control signal having a duty cycle that varies proportional to the comparator output signal. A drive circuit has an input terminal to which the control signal is applied and an output terminal connected to the motor. The drive circuit generates a motor drive signal proportional to the control signal for driving said motor. A current command control circuit has an input terminal to which the current control signal is applied and an output terminal to which the current command signal is applied. The current command control circuit generates a signal proportional to the control signal and reduces the current command signal when the proportional signal is less than the current command signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.