| 摘要 |
PCT No. PCT/DK82/00063 Sec. 371 Date Mar. 4, 1983 Sec. 102(e) Date Mar. 4, 1983 PCT Filed Jul. 6, 1982 PCT Pub. No. WO83/00246 PCT Pub. Date Jan. 20, 1983.An alarm system for safeguarding against the breakthrough of a wall includes a network of electrically conducting wires distributed over the wall and arranged to lie in at least two layers which are spaced a small distance from each other. The wires are comprised of a series consisting of a predetermined number of wires running uninterrupted through the layers with each wire having an input terminal in a corresponding output terminal. Some of the input terminals are provided with a first voltage or signal and other input terminals are provided with a second voltage or signal which is different from the first voltage or signal. An electronic device is connected to the output terminals for actuating an alarm when the voltage or signal on any one of the output terminals does not correspond to the voltage or signal on the corresponding input terminal. |
