| 摘要 |
<p>The alarm circuit has the fixed and movable frame elements (1, 2) of each window or door connected at one side with an electric alarm source (3) and at the other side connected with one another via a lock (5) so that a series current loop (4) for the alarm source (3) is formed between the movable and fixed frame elements (1, 2). Pref. one end of the series current loop is attached to the movable frame element (1), to which the alarm source (3) is connected, and the other end of the series current loop (4) is releasably attached to the fixed frame element (2) via the lock (5).</p> |
