Electric fence

**1. Design and Function of Electric Fences:**
– Electric fences complete an electrical circuit when touched by an animal.
– Power energizer converts power into high voltage pulses.
– Animal touching the wire and earth during a pulse conducts the shock.
– Effects of the shock depend on voltage, energy, and degree of contact.
– Voltage multiplier-based energizers store high voltage potential.

**2. Fence Energizers and Materials:**
– Early AC fence chargers used transformers and mechanically-driven switches.
– Later systems replaced switches with solid-state circuits.
– Weed burner chargers destroyed weeds but caused grass fires.
– Modern energizers emit high voltage pulses at intervals.
– Energizers can be powered by batteries or solar panels.
– Smooth steel wire is commonly used for electric fences.
– Woven wire or barbed wire fences can also be electrified.
– Synthetic webbing and rope-like materials are available for visibility.
– Fences must be insulated from the earth and conducting materials.
– Insulators are attached to wooden or plastic posts.

**3. Uses and Innovations of Electric Fences:**
– Electric fences are cheaper and faster to construct compared to conventional fences.
– They lower the risk of injury to livestock.
– Temporary electric fencing supports managed intensive grazing and overnight confinement of animals.
– Electric fences are effective in controlling the movements of wild animals.
– Used in agriculture, wild animal control, small livestock farming, and airport runways.
– Inventions like non-shortable electric fences and moveable fence components have improved efficiency.
– Adoption of high tensile steel fence wire and synthetic materials has enhanced durability.

**4. Regulations and Materials in Electric Fencing:**
– Underwriters Laboratories and ANSI/UL standards have regulated electric fence controllers.
– Changes in laws occurred, allowing certain types of electrical outputs for fences.
– Introduction of synthetic webbing, rope-like fencing materials, and plastic insulators.
– Polyethylene insulators are cheaper and less breakable than porcelain.
– High tensile steel fence wire was introduced in the 1970s.
– Moveable fence components like Tumblewheel enable mobile one-wire fences for rotational grazing.

**5. Security and Impact on Animals:**
– Security electric fences are used for perimeter security in various sectors.
– Non-lethal and lethal electric fences are used for animal management and security purposes.
– Impact on vulnerable species like pangolins and reptiles.
– Lethal fences have been historically used for anti-personnel purposes.
– Electrified fences cause harm to various species, with significant annual death estimates for reptiles and pangolins.