Electric Fence Perimeter Intrusion Detection System

An electric fence is based on vertical or overhang electrified wires. The system makes use of wires fitted on insulators and powered by an energizer that is capable of delivering a substantial and most uncomfortable shock.The energizer in simple terms is a transformer that can convert low power to a huge quantity of power to the intruder touching the wires. The energizer used for this purpose will not allow anyone to be killed as the unit is designed to allow the power to pulsate on/off on a continuous basis. Therefore, the electric fence power switches on and off momentarily and therefore is termed a non-lethal electric fence.

 

Principle of Operation

The dual loop energizer applies the detection and pulse voltages by using the fence configuration shown below. An AC voltage is applied to each fence loop (Loop A and Loop B) simultaneously, with the voltage applied to Loop A being 180 out of phase with the voltage applied to Loop B. This ensures that there is always a potential difference between the two loops and between any loop and ground. An end-of-line resistor is connected between the end of each loop and earth to provide a ground return. This facilitates the detection of an open circuit (cut) of a fence loop generating a continuous alternating voltage that is applied to the feed terminals of the fence by means of isolation.

 

Dual Loop Energizer

The system contains Dual Loop Energizer The purpose of the dual loop energizer is to ensure that detection and pulse voltages are applied to the fence in such a way that there is always a potential difference present between adjacent fence wires and between any fence wire and earth.

 

Advantages of an Electric Fence

There are three main advantages of an electric fence installation:

• Visual appearance- deterrence

• Shock capacity

• Alarm given

 

Alarm

• Electric fence will go to an alarm when the wire is cut or shorted

• Electric fence will have served its purpose as an early warning device should the above occur.