On Sep 28, 9:25 pm, larkim wrote:
On Sep 27, 11:53 pm, Matty F wrote:

On Sep 27, 9:20 pm, (Andrew Gabriel)
wrote:

Decided to make an electric slug fence yesterday, after my new
autumn crocus shoots got eaten for the second night in a row.

http://www.facebook.com/photo.php?pi...17&id=16195464...

No slug damage this morning!

I was going to make a slug/snail electric fence for my new garden.
I already have a 12 volt DC supply nearby so I was intending to run
two bare copper wires about a quarter of an inch apart on the timber
around the garden. After reading this I will put a resistor in the
supply line!

My wife will be interested in this. But please explain to me what the
resistor is for? I'm sure my physics GCSE (grade B, 1988) will
stretch to me actually understanding it, but I can't bring enough pre-
existing knowledge to understand it on my own!! Also, why the LED?

The resistor would be just to limit the current in case of a short,
e.g. a whole pile of dead slugs across the wires!. I already have a
fuse but I don't want that to blow or I could lose my garden
overnight. According to the OP, only a very small current is enough to
stop the slugs.