| 摘要 |
The door drive has an electric motor that can normally be driven via an output stage (19), a mains power supply for normal operation and an auxiliary drive for abnormal or emergency operation. At least two electric motors (21a,21b) can be driven individually or synchronously. The motors can be driven from a d.c. power supply (35) if the mains supply fails. A changeover arrangement (25,51,53) can connect the motors to the battery supply, pref. by bypassing the output stage, to enable them to be driven in abnormal or emergency mode. |
