Re: [Phys-l] Chimp unsuccessfully hangs from high voltage line

["John Clement" <clement@hal-pc.org>]

Apparently the source impedence is not always high enough to prevent injury
to all small animals.  We use electric fences to keep predators away from
roosting poultry.  One in a while a small animal such as a chipmunk would be
found dead by the fence.  Of course it could have been that they had heart
problems and the shock precipitated a heart failure.

John M. Clement
Houston, TX

>      The source impedance is high enough to avoid permanent injury to
> animals.   But this leads to a problem.    The grass that is no longer
>   nibbled, grows to touch the wire, and this can easily emasculate
>   the pulse.
>
> A recent approach to fence charging takes a different tack: a high
> voltage pulse is still generated, but now, its output is lower impedance.
> Instead, its duration is limited in   order to avoid injuring the
> quadrupeds. These are billed as "Low impedance" in that they are
>   not disabled by moderate grass/weed loading.
>   Chargers are also rated by pulse energy:
> 0.1 J to 1.5 J are to be seen in the feed store.