A power fence is a psychological barrier
that keeps farm animals in and wild
animals and vermin out – even over
long distances.
A pulsed electric current is sent along
the fence wire, about one pulse per
second, from an energizer which is
earthed. When the animal touches the
fence it completes the circuit between
the fence and the ground and receives
a short, sharp but safe shock. The shock
is sufficiently memorable that the animal never forgets. If the ground is
very dry, the fence may require an
earth return wire (refer figures 4.9(a)
and 4.9(b)).
A power fence is a psychological barrier
so doesn’t need great physical strength.
However, it must be well designed and
constructed to absorb some pressure
from animals, snow and wind. The
energizer must have enough power for
the length of fence and for the animals
being controlled.
Resistance
It is important to understand how the
resistance of different leadout wires
can affect the performance of your
electric fence.
Resistance (Ohms) measures a wire’s ability to conduct electricity (current).
The lower the Ohms, the more current
it will conduct. It has the same effect as
the friction of a water pipe has on
water flow. Voltage in electricity is like
pressure in water. Electric current
(amps) is like water volume or flow.
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