| 摘要 |
<p>An alarm system in the form of a support layer is arranged to be secured to a wall, and is provided with a printed circuit of a series (1) of electrical conducting wires in a particular pattern (fig. 1) on both the front and the back. The wires lie very close side by side and crosswise to each other, thus forming a mesh pattern. Some of the wires are current-carrying while others are not. If just one of the wires is cut over or carries a voltage other than that applied to it, the alarm is activated. The alarm system is simple and easy to produce because printed circuits are used, and the support layer is impossible to break through.</p> |
