System and method for detecting D.C. motor circuit failures
US5652525A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1992 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Mar 16, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P29/0241
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus and method are provided for determining and indicating if certain types of circuit failures have occurred in a D.C. motor circuit such as a locked rotor condition, a short-circuit or an open circuit. The method includes the steps of, and the apparatus involves applying a voltage to two leads of the D.C. motor sufficient to cause motor rotation, determining if flyback exists, determining if back EMF exists, and, finally, if a back EMF does not exist and flyback does exist then indicating a locked rotor condition. However, if a back EMF does not exist and flyback does not exist then an indication is provided that either an open-circuit or short-circuit condition exists. The same apparatus and method can be used with a voltage not sufficient to cause motor rotation, although given this limitation only flyback can be detected, so that only an open-circuit or short-circuit condition can be indicated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.