I haven't followed much of this string, but I would
think you could do something with a neon light bulb
and a bit of wire as an antenna, if needed.  Electric
fences don't pack a lot of current, but I would think
you could get a neon light bulb or even a small
flourescent tube to light up next to the electric
fence without physically contacting it.

--- Carl Denk <cdenk@alltel.net> wrote:

> Thanks much!. :)   I'll try the suggestion in the
> next day or 2. Outdoor 
> work has me busy at the moment, but rain should
> drive me in over the 
> weekend. Those links look very good also.
> 
> Jinx wrote:
> >> Some other fence controllers (power supplies)
> have electronics and
> >> DO pulse, but not my cheap model.
> >>     
> >
> > In that case then you really are measuring plain
> AC. If you assume it's
> > 660VAC, you could use a standard red LED, Vf =
> 1.7, I = 5mA
> >
> > R = (E - Vf) * 1000/ImA
> >
> > R = (660 - 1.7) * 1000/5
> >
> > R = 658.3 * 200
> >
> > R = 131.660k
> >
> > Put a reverse parallel diode (1N914) across the
> LED. Resistor will need
> > to withstand 660VAC (don't know whether you're
> measuring pk-pk or
> > RMS) and would be better made of several smaller R
> in series. General
> > purpose Rs are usually 200V rated, but err on the
> cautious side. If the
> > LED is dim you could reduce R in increments to get
> the brightness you
> > want. Rather depends on the specs of the LED
> >
> > Alternatively a dropping capacitor to limit
> current (with suitable voltage
> > rating, eg 1kV). 1uF will pass approx 70mA, so
> 68nF will allow about
> > 5mA through. Some examples and principles of
> AC-powered LEDs here
> >
> >
>
http://ourworld.compuserve.com/homepages/Bill_Bowden/page10.htm
> >
> >
>
http://www.discovercircuits.com/H-Corner/AC-Powered.htm
> >
> > Google about for others
> >
> >   
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