26 May 1995


Most fencing units follow the principles shown here by Gallaghers B150, though not all use plug-together construction. Three main blocks work together to produce a very short 0.003sec current pulse whose shape is tailored to give minimum losses in the fence and produce a memorable effect in the animal.

In the picture above, the module (A) controls pulse shape, the interval between pulses and their duration. Battery power is stepped up to 600V on its circuit board and stored in the capacitor (B), which releases it into the transformer (C) at the modules signal. In the transformer, voltage is taken up to 7kV-10kV before delivery to the fence.

Where pulse interval is variable – either randomly or between day/night – the module carries a photocell to detect light levels and a switch for different modes.