| 摘要 |
<p>In safety circuits for braking or arresting devices (7) of flywheel masses or machine parts, especially a revolving door, which are driven by electric motor and can be switched on electrically, in which at least one of two edges moving toward each other is provided with a pressure-sensitive electrical switching member (3) for generating interference signals. Interference signals generated during a disturbance are sent to an electronic control unit (1) and are used, by an electronic switch (8), to switch off the drive motor (10) and/or to switch on a braking or arresting device (7). The movement of the part provided with the movable edge or element is stopped even when the electrical switch (8) of the control unit (1) does not respond correctly in the presence of an interference signal. The reliability of the safety circuit is continuously checked. An electronic switching unit (2), which interrupts the continuous excitation of a safety relay (4) having at least three relay contact switches (a, b, c) and at least one closing contact (a, b, or c), is connected before the electronic control unit (1). The relay contact switches (a, b, c) switch the circuits (9, 6) of the drive motor (10) and of the braking or arresting device (7), as well as a control circuit (11).</p> |
