| 摘要 |
The wire comprises a central conductor (1) jacketed by a thin insulating sheath (2) and surrounded by conductors (3). The conductor (1) and one of the conductors (3) are connected to a resistance bridge, the diagonal of which is connected to an amplifier controlling an acoustic alarm. Any pressure on the wire (wire-cutter, weight of a person trying to scale the fence, etc.) moves the wire (3) closer to the wire (1) and causes the contact resistance between these two wires or the capacitance to vary, which destroys the balance of the bridge and triggers the acoustic alarm. <IMAGE>
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