| 摘要 |
<p>A door system (100) comprises a door (102), a direct current, DC, electric motor (104) configured to operate the door and a control unit (114). The DC motor comprises a first pair of brushes arranged at a commutator of the DC motor and configured to be connected to at least a first source of electric power (108), and a second pair of brushes arranged at the commutator of the DC motor and configured to be connected to at least a second source of electric power (112). The control unit is configured to detect damage to the first pair of brushes and, in dependence of such detection, disconnect the first pair of brushes from the first source and connect the second pair of brushes to the second source. That is, a redundant channel of power is provided that can be utilized when a first channel of power has been damaged, thereby maintaining safety critical functionality.</p> |
