Hi people,

Following a near death experience at the hands of an illegal immigrant
and his gang who suddenly tipped out of the back of a lorry just north of
J9 of the M3 in Hampshire (clearly they're coming in via Southampton as
well) I've decided that since the government doesn't give a f*ck about
our personal security I'd better do something about it myself. The first
thing that sprang to mind was to construct an electric fence. We used to
knock these up for fun in the 1960s using old Post Office relays in a
make/break configuration. It was dead simple, cheap and relatively non-
lethal. But that was 50 years ago and times have moved on ('elf & safety
etc).
So how could a fence best be implemented using current technology? One of
the main drawbacks of the old relay system was that it was very
inefficient, being permanently 'on' whether there were any intruders or
not. I'm now thinking perhaps it would be better to use MOSFETS and a 555
timer to chop the current supply to a large inductor say 20 times a
second once an earth path has been detected on the fence's live wire. How
best to detect this earth path, though? Bearing in mind it would have to
work in rain and shine. And how best to limit the current to non-lethal
levels?
All constructive suggestions welcome, cheers.