Overload protection for series resistances of electric motors, especially of fans of vehicles driven by electric motors
US4752851A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 26, 1986 |
| Grant date | Jun 21, 1988 |
| Priority date | — |
| Expiry date | Sep 26, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/91
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Overload protection for the series resistance of an electric motor in which a voltage drop across the electric motor is monitored. During the occurrence of a reduced voltage drop, for example, as a result of a blocking of the motor or of a fan driven by the electric motor, the series resistance is short-circuited by a relay so that the blocking can be overcome by an increased driving torque of the electric motor or a fuse in the load current input line to the motor responds. As a result thereof, an effective overload protection is created which is of simple construction, involves no additional wiring expenditure and requires few additional components and which also permits to dimension the series resistance for normal operating currents and to be able to dispense with a thermal monitoring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.