| 摘要 |
<p>A device for controlling a door, the device comprising: a body; an electromagnet arranged to generate a magnetic field for retaining the door; a coupling means that couples the electromagnet to the body, the coupling means being arranged to allow a movement of the electromagnet relative to the body; and a current supply means that is arranged to supply the electromagnet with a current, the current supply means being further arranged to detect the movement of the electromagnetic and to cease supplying the current at a predetermined instant after detecting the movement of the electromagnet.</p> |
