Pet fence

A pet fence or fenceless boundary is an electronic system designed to keep a pet or other domestic animal within a set of predefined boundaries without the use of a physical barrier. A mild electronic shock is delivered by an electronic collar if its warning sound is ignored. The system was first invented and patented by Richard Peck in 1973 and was held until 1990 by Invisible Fence Co, now known as Invisible Fence Inc.

The pet wears a lightweight collar which emits a warning sound when the pet nears the boundary. If the warning is ignored and the pet crosses beyond the boundary of the fence, the pet receives a mild electric shock from the collar. The stimulus delivered to the pet may be applied more frequently and at greater strength as the animal approaches the boundary. The pet soon learns to avoid the invisible fence location, making it an effective virtual barrier. Animals (including humans) not wearing the collar are unaffected by the defined boundaries.

Although called "fences", these fence less boundary systems are more accurately termed electronic pet containment systems. In cost analysis they have shown to be much cheaper and more aesthetically pleasing than physical fences. However, an electronic fence may not be effective if an animal crosses a boundary while in a state of excitement. Pet fences are also used sometimes to contain in circumstances where ordinary agricultural fencing is not convenient or legal, such as on British common land.

In some pet fence systems, there is a wire (which may be buried) that emits a radio signal to activate the receiver collar. Other pet fences are wireless. Rather than using an underground wire, they emit a radio signal from a central unit, and activate when the pet travels beyond a certain radius from the unit.

In another type, the collar uses GPS signals to determine proximity to a predetermined "virtual fence", without the need for any physical installation at all. This system allows some additional flexibility, such as simpler inclusion of "islands" within the containment area, and easier changes to the boundary, although location of the boundary is not as precise due to GPS tolerances.

In addition, some collars have multiple settings, allowing owners to have a collar emit a tone only, or one of several levels of static shock, with higher levels used to contain bigger, stronger dogs.

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Wikipedia