On Mon, 22 Sep 2003 22:56:02 +0100, Chris Wilson
wrote:

You can buy some sort of neon indicators from the electric
fence makers, but they are about 20 quid each...

Neon and a capacitor (maybe 0.22uF) in parallel, fed from a bridge
rectifier. Cost a quid or so.

--
Smert' spamionam

Andy Dingley wrote:

Neon and a capacitor (maybe 0.22uF) in parallel, fed from a bridge
rectifier. Cost a quid or so.

Why the capacitor? If the fence is pulsed, as all of ours are
(at ~ 1 Hz) then just a neon with a ~1M resistor works great.

--
Grunff

In article ,
says...
Andy Dingley wrote:

Neon and a capacitor (maybe 0.22uF) in parallel, fed from a bridge
rectifier. Cost a quid or so.

Why the capacitor? If the fence is pulsed, as all of ours are
(at ~ 1 Hz) then just a neon with a ~1M resistor works great.

Neon as in a mains tester screwdriver neon? Are neons different voltages?
The HT lead to the bird enclosure runs for about 40 yards, and passes
through the roof space of a shed, the fluorescent tube it passes by
"pulses" dimly, even when off. Pity it's in the shed, or that would do
VBG Thanks for replies. If the signal lamp was fairly bright could see
it from the house, which would be good.

--
Best Regards,
Chris.

Chris Wilson wrote:

Neon as in a mains tester screwdriver neon?

A mains tester screwdriver contains a neon bulb and a series
resistor. The neon bulb is just a small glass envelope with low
pressure neon and two electrodes


Are neons different voltages?

Not as such - you need to limit the current through them with a
resistor, the value of which will depend on your voltage.


If the signal lamp was fairly bright could see
it from the house, which would be good.

Depends what your HT circuit's like, but I suspect if you were
drawing that much power from it there wouldn't be much left to
mainain a good fence voltage.

--
Grunff

In article ,
says...
In article ,
says...
Andy Dingley wrote:

Neon and a capacitor (maybe 0.22uF) in parallel, fed from a bridge
rectifier. Cost a quid or so.

Why the capacitor? If the fence is pulsed, as all of ours are
(at ~ 1 Hz) then just a neon with a ~1M resistor works great.

Neon as in a mains tester screwdriver neon? Are neons different voltages?
The HT lead to the bird enclosure runs for about 40 yards, and passes
through the roof space of a shed, the fluorescent tube it passes by
"pulses" dimly, even when off. Pity it's in the shed, or that would do
VBG Thanks for replies. If the signal lamp was fairly bright could see
it from the house, which would be good.



Sorted now, and I feel a bit of a fool. Being in the motor trade I should
have realized that a drawer in the workshop contained a spark indicator
neon to go onto spark plug leads to check for HT to a plug. Worked fine,
zero cost. Sincere thanks for all the replies!
--
Best Regards,
Chris.