I want to know if something (an electric fence) is turned on and I
don't particularly want to traipse out to the shed where the fence
energiser is to check.

It gets turned on and off throughout the day as different people go in
and out to check their horses so there is always a fair chance that it
might not get turned back on, especially if visits overlap.

So I'm wondering how I might rig up some sort of remote indicator that
will let me check whether it's on or not. Ideally it would be
possible for a computer to monitor it as I could then have an alarm of
some sort if it was off for, say, more than an hour.

The fence energiser is mains powered and in a building visible from
the house, something very simple and mains powered would do the job as
it can simply be powered from the same socket as the energiser, when
off there would be a 'lack of signal'. However I'm not quite sure how
to signal from there to the house (50 yards maybe). I don't really
want a whole WiFi connection just for an on/off indication. Can one
get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
sight to one of my WiFi routers so that should be OK. What's the
minimal sort of device for saying "I'm alive"?

--
Chris Green
·

On 23/11/2023 09:33, Chris Green wrote:
> I want to know if something (an electric fence) is turned on and I
> don't particularly want to traipse out to the shed where the fence
> energiser is to check.
>
> It gets turned on and off throughout the day as different people go in
> and out to check their horses so there is always a fair chance that it
> might not get turned back on, especially if visits overlap.
>
> So I'm wondering how I might rig up some sort of remote indicator that
> will let me check whether it's on or not. Ideally it would be
> possible for a computer to monitor it as I could then have an alarm of
> some sort if it was off for, say, more than an hour.
>
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'. However I'm not quite sure how
> to signal from there to the house (50 yards maybe). I don't really
> want a whole WiFi connection just for an on/off indication. Can one
> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> sight to one of my WiFi routers so that should be OK. What's the
> minimal sort of device for saying "I'm alive"?
>
A cheap LED torch fixed to the shed and pointing at the house. Switched
on with a relay whenever the supply to the fence is off. Add a timer to
make the torch flash after an hour.
Alternatively (and more expensively) there are several GSM-based "phone
home" devices that can be configured to call your mobile. Search for
<mains power failure alarm> or similar

In message <nri33k-vrrp2.ln1@esprimo.zbmc.eu>, Chris Green <cl@isbd.net>
writes
>I want to know if something (an electric fence) is turned on and I
>don't particularly want to traipse out to the shed where the fence
>energiser is to check.
>
>It gets turned on and off throughout the day as different people go in
>and out to check their horses so there is always a fair chance that it
>might not get turned back on, especially if visits overlap.
>
>So I'm wondering how I might rig up some sort of remote indicator that
>will let me check whether it's on or not. Ideally it would be
>possible for a computer to monitor it as I could then have an alarm of
>some sort if it was off for, say, more than an hour.
>
>The fence energiser is mains powered and in a building visible from
>the house, something very simple and mains powered would do the job as
>it can simply be powered from the same socket as the energiser, when
>off there would be a 'lack of signal'. However I'm not quite sure how
>to signal from there to the house (50 yards maybe). I don't really
>want a whole WiFi connection just for an on/off indication. Can one
>get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>sight to one of my WiFi routers so that should be OK. What's the
>minimal sort of device for saying "I'm alive"?

Going sideways.... I assume the visitors have to crouch under the fence
for access. Could you install a gate and have the fence wire routed
across above head height.
>

--
Tim Lamb

On 23/11/2023 09:33, Chris Green wrote:
> I want to know if something (an electric fence) is turned on and I
> don't particularly want to traipse out to the shed where the fence
> energiser is to check.
>
> It gets turned on and off throughout the day as different people go in
> and out to check their horses so there is always a fair chance that it
> might not get turned back on, especially if visits overlap.
>
> So I'm wondering how I might rig up some sort of remote indicator that
> will let me check whether it's on or not. Ideally it would be
> possible for a computer to monitor it as I could then have an alarm of
> some sort if it was off for, say, more than an hour.
>
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'. However I'm not quite sure how
> to signal from there to the house (50 yards maybe). I don't really
> want a whole WiFi connection just for an on/off indication. Can one
> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> sight to one of my WiFi routers so that should be OK. What's the
> minimal sort of device for saying "I'm alive"?
>

Try using an AM radio. Most simple electric fences radiate "clicks".

PA

On 23/11/2023 09:33, Chris Green wrote:
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'. However I'm not quite sure how
> to signal from there to the house (50 yards maybe). I don't really
> want a whole WiFi connection just for an on/off indication. Can one
> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> sight to one of my WiFi routers so that should be OK. What's the
> minimal sort of device for saying "I'm alive"?

Add some sort of wifi gadget, powered from the same power as the fence,
then set up your laptop to ping the gadget at regular intervals.
PingInfoView can do that, and sound an alarm, send you an email, when
the pong fails.

The 'gadget', could be a Smart Plug, IP camera, old wifi router, old
wifi capable phone - anything which has wifi capability.

On 23/11/2023 09:33, Chris Green wrote:

>
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'.

Does the shed mains power go via the house. If so, put a sonoff/tasmota
WiFi power meter on the entire mains cable in/near the house.

A sonoff/tasmota style power meter isn't simple, but it is cheap.

Chris Green <cl@isbd.net> wrote:
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'. However I'm not quite sure how
> to signal from there to the house (50 yards maybe). I don't really
> want a whole WiFi connection just for an on/off indication. Can one
> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> sight to one of my WiFi routers so that should be OK. What's the
> minimal sort of device for saying "I'm alive"?

If you had a wifi access point with enough range to reach the house (might
need a directional antenna) you could write something on the computer to
detect the presence of the 'Electric_Fence' wifi network?

eg on my Ubuntu machine:

$ nmcli device wifi list | grep Electric_Fence
11:22:33:44:55:66 Electric_Fence Infra 1 130 Mbit/s 30 WPA2 WPA3

You don't need to connect to the network, just detect its presence when
scanning for available wifi networks.

Similar could be done with other kinds of RF (eg 433/868MHz) which would
have longer range although you might need to disambiguate from other sources
of those (eg car remote unlockers, tyre pressure sensors, etc). There is
software 'rtl_433' to use a cheap TV dongle to decode them.

Theo

On 23/11/2023 09:33, Chris Green wrote:
> I want to know if something (an electric fence) is turned on and I
> don't particularly want to traipse out to the shed where the fence
> energiser is to check.
>
> It gets turned on and off throughout the day as different people go in
> and out to check their horses so there is always a fair chance that it
> might not get turned back on, especially if visits overlap.
>
> So I'm wondering how I might rig up some sort of remote indicator that
> will let me check whether it's on or not. Ideally it would be
> possible for a computer to monitor it as I could then have an alarm of
> some sort if it was off for, say, more than an hour.
>
> The fence energiser is mains powered and in a building visible from
> the house, something very simple and mains powered would do the job as
> it can simply be powered from the same socket as the energiser, when
> off there would be a 'lack of signal'. However I'm not quite sure how
> to signal from there to the house (50 yards maybe). I don't really
> want a whole WiFi connection just for an on/off indication. Can one
> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> sight to one of my WiFi routers so that should be OK. What's the
> minimal sort of device for saying "I'm alive"?
>

KISS indeed. A lamp in a tube directed to the house window you would
view from. Works ok for Railtrack. Lamp on = fence powered and assumed
working order

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

On 11/23/2023 5:55 AM, N_Cook wrote:
> On 23/11/2023 09:33, Chris Green wrote:
>> I want to know if something (an electric fence) is turned on and I
>> don't particularly want to traipse out to the shed where the fence
>> energiser is to check.
>>
>> It gets turned on and off throughout the day as different people go in
>> and out to check their horses so there is always a fair chance that it
>> might not get turned back on, especially if visits overlap.
>>
>> So I'm wondering how I might rig up some sort of remote indicator that
>> will let me check whether it's on or not.  Ideally it would be
>> possible for a computer to monitor it as I could then have an alarm of
>> some sort if it was off for, say, more than an hour.
>>
>> The fence energiser is mains powered and in a building visible from
>> the house, something very simple and mains powered would do the job as
>> it can simply be powered from the same socket as the energiser, when
>> off there would be a 'lack of signal'.  However I'm not quite sure how
>> to signal from there to the house (50 yards maybe).  I don't really
>> want a whole WiFi connection just for an on/off indication.  Can one
>> get a sort of WiFi 'beacon' that simply says "I'm here"?  It's line of
>> sight to one of my WiFi routers so that should be OK.  What's the
>> minimal sort of device for saying "I'm alive"?
>>
>
> KISS indeed. A lamp in a tube directed to the house window you would view from. Works ok for Railtrack. Lamp on = fence powered and assumed working order
>

They make Wifi multimeters. But then you need power for it.

https://www.fluke.com/en-ca/product/electrical-testing/digital-multimeters/fluke-3000-fc

Apparently one way to detect run-state, is by measuring a current
on the fencer. Rather than measuring voltage. You would need a 10:1 or
100:1 probe to handle voltages higher than the meter rating. Sometimes
current can be handled on "low-side" to make safe monitoring readings.

A mains powered device could be measured with a Kill-O-Watt meter.

This Kill-O-Watt apparently has wireless, but there are many details
which don't match your physical location, so this is merely a demo
that such a thing exists. And Google is flat out refusing to help on this,
returning a random spray of garbage.

https://www.rpelectronics.com/p4200-kill-a-watt-wireless-power-meter-by-p3.html

Paul

On Thu, 23 Nov 2023 09:59:13 +0000, nothanks@aolbin.com wrote:

>On 23/11/2023 09:33, Chris Green wrote:
>> I want to know if something (an electric fence) is turned on and I
>> don't particularly want to traipse out to the shed where the fence
>> energiser is to check.
>>
>> It gets turned on and off throughout the day as different people go in
>> and out to check their horses so there is always a fair chance that it
>> might not get turned back on, especially if visits overlap.
>>
>> So I'm wondering how I might rig up some sort of remote indicator that
>> will let me check whether it's on or not. Ideally it would be
>> possible for a computer to monitor it as I could then have an alarm of
>> some sort if it was off for, say, more than an hour.
>>
>> The fence energiser is mains powered and in a building visible from
>> the house, something very simple and mains powered would do the job as
>> it can simply be powered from the same socket as the energiser, when
>> off there would be a 'lack of signal'. However I'm not quite sure how
>> to signal from there to the house (50 yards maybe). I don't really
>> want a whole WiFi connection just for an on/off indication. Can one
>> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>> sight to one of my WiFi routers so that should be OK. What's the
>> minimal sort of device for saying "I'm alive"?
>>
>A cheap LED torch fixed to the shed and pointing at the house. Switched
>on with a relay whenever the supply to the fence is off. Add a timer to
>make the torch flash after an hour.
>Alternatively (and more expensively) there are several GSM-based "phone
>home" devices that can be configured to call your mobile. Search for
><mains power failure alarm> or similar

Would a low-voltage LED with a diode in series, wired across a
low-value resistor in the mains neutral return from the fence
energiser work? When the fence energiser switches on, there'd be a
small drop in AC voltage across said resistor, say a volt or two,
rectified by the diode and enough to light the LED. Choice of resistor
value would be important to develop a small voltage without stopping
the fence energiser from working.

Or would there just be a bang and puff of smoke? :-)

--
Chris

Harry Bloomfield Esq <a@harrym1byt.plus.com> wrote:
> On 23/11/2023 09:33, Chris Green wrote:
> > The fence energiser is mains powered and in a building visible from
> > the house, something very simple and mains powered would do the job as
> > it can simply be powered from the same socket as the energiser, when
> > off there would be a 'lack of signal'. However I'm not quite sure how
> > to signal from there to the house (50 yards maybe). I don't really
> > want a whole WiFi connection just for an on/off indication. Can one
> > get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> > sight to one of my WiFi routers so that should be OK. What's the
> > minimal sort of device for saying "I'm alive"?
>
> Add some sort of wifi gadget, powered from the same power as the fence,
> then set up your laptop to ping the gadget at regular intervals.
> PingInfoView can do that, and sound an alarm, send you an email, when
> the pong fails.
>
> The 'gadget', could be a Smart Plug, IP camera, old wifi router, old
> wifi capable phone - anything which has wifi capability.

Yes, I think this may be the best answer. I have a couple of WiFi
enabled microcontrollers that should do the job. I'm just trying an
ESP32 based one and it seems to be possible, I'm not quite sure about
the range yet.

--
Chris Green
·

Peter Able <stuck@home.com> wrote:
> On 23/11/2023 09:33, Chris Green wrote:
> > I want to know if something (an electric fence) is turned on and I
> > don't particularly want to traipse out to the shed where the fence
> > energiser is to check.
> >
> > It gets turned on and off throughout the day as different people go in
> > and out to check their horses so there is always a fair chance that it
> > might not get turned back on, especially if visits overlap.
> >
> > So I'm wondering how I might rig up some sort of remote indicator that
> > will let me check whether it's on or not. Ideally it would be
> > possible for a computer to monitor it as I could then have an alarm of
> > some sort if it was off for, say, more than an hour.
> >
> > The fence energiser is mains powered and in a building visible from
> > the house, something very simple and mains powered would do the job as
> > it can simply be powered from the same socket as the energiser, when
> > off there would be a 'lack of signal'. However I'm not quite sure how
> > to signal from there to the house (50 yards maybe). I don't really
> > want a whole WiFi connection just for an on/off indication. Can one
> > get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> > sight to one of my WiFi routers so that should be OK. What's the
> > minimal sort of device for saying "I'm alive"?
> >
>
> Try using an AM radio. Most simple electric fences radiate "clicks".
>
Good point, annoying usually but this could be the answer!

--
Chris Green
·

On 23/11/2023 13:06, Chris Hogg wrote:
> On Thu, 23 Nov 2023 09:59:13 +0000, nothanks@aolbin.com wrote:
>
>> On 23/11/2023 09:33, Chris Green wrote:
>>> I want to know if something (an electric fence) is turned on and I
>>> don't particularly want to traipse out to the shed where the fence
>>> energiser is to check.
>>>
>>> It gets turned on and off throughout the day as different people go in
>>> and out to check their horses so there is always a fair chance that it
>>> might not get turned back on, especially if visits overlap.
>>>
>>> So I'm wondering how I might rig up some sort of remote indicator that
>>> will let me check whether it's on or not. Ideally it would be
>>> possible for a computer to monitor it as I could then have an alarm of
>>> some sort if it was off for, say, more than an hour.
>>>
>>> The fence energiser is mains powered and in a building visible from
>>> the house, something very simple and mains powered would do the job as
>>> it can simply be powered from the same socket as the energiser, when
>>> off there would be a 'lack of signal'. However I'm not quite sure how
>>> to signal from there to the house (50 yards maybe). I don't really
>>> want a whole WiFi connection just for an on/off indication. Can one
>>> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>>> sight to one of my WiFi routers so that should be OK. What's the
>>> minimal sort of device for saying "I'm alive"?
>>>
>> A cheap LED torch fixed to the shed and pointing at the house. Switched
>> on with a relay whenever the supply to the fence is off. Add a timer to
>> make the torch flash after an hour.
>> Alternatively (and more expensively) there are several GSM-based "phone
>> home" devices that can be configured to call your mobile. Search for
>> <mains power failure alarm> or similar
>
> Would a low-voltage LED with a diode in series, wired across a
> low-value resistor in the mains neutral return from the fence
> energiser work? When the fence energiser switches on, there'd be a
> small drop in AC voltage across said resistor, say a volt or two,
> rectified by the diode and enough to light the LED. Choice of resistor
> value would be important to develop a small voltage without stopping
> the fence energiser from working.
>
> Or would there just be a bang and puff of smoke? :-)
>
Would it work - possibly, if you got the sums right, but it would be
more reliable and easier to have a few back-back diodes in series.
Having said that, I would simply use a relay (perhaps one with in-built
adjustable delay such as
https://knxshoponline.co.uk/pcm-02-time-relay-switch-off-delay-230v-ac/)
to switch a cheap LED torch. If you're concerned about battery life then
use one of the many wall warts you probably have in a box somewhere) to
replace the batteries.

Chris Green <cl@isbd.net> wrote:
> Harry Bloomfield Esq <a@harrym1byt.plus.com> wrote:
> > On 23/11/2023 09:33, Chris Green wrote:
> > > The fence energiser is mains powered and in a building visible from
> > > the house, something very simple and mains powered would do the job as
> > > it can simply be powered from the same socket as the energiser, when
> > > off there would be a 'lack of signal'. However I'm not quite sure how
> > > to signal from there to the house (50 yards maybe). I don't really
> > > want a whole WiFi connection just for an on/off indication. Can one
> > > get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> > > sight to one of my WiFi routers so that should be OK. What's the
> > > minimal sort of device for saying "I'm alive"?
> >
> > Add some sort of wifi gadget, powered from the same power as the fence,
> > then set up your laptop to ping the gadget at regular intervals.
> > PingInfoView can do that, and sound an alarm, send you an email, when
> > the pong fails.
> >
> > The 'gadget', could be a Smart Plug, IP camera, old wifi router, old
> > wifi capable phone - anything which has wifi capability.
>
> Yes, I think this may be the best answer. I have a couple of WiFi
> enabled microcontrollers that should do the job. I'm just trying an
> ESP32 based one and it seems to be possible, I'm not quite sure about
> the range yet.
>
The range is the issue, nothing like what I need even with
line-of-sight between router and the ESP32 microcontroller. If the
range was OK it would work perfectly, so maybe I need to find an ESP32
board (or similar) with an aerial.

--
Chris Green
·

On Thursday, 23 November 2023 at 21:18:07 UTC, Chris Green wrote:
> Chris Green <c...@isbd.net> wrote:
> > Harry Bloomfield Esq <a...@harrym1byt.plus.com> wrote:
> > > On 23/11/2023 09:33, Chris Green wrote:
> > > > The fence energiser is mains powered and in a building visible from
> > > > the house, something very simple and mains powered would do the job as
> > > > it can simply be powered from the same socket as the energiser, when
> > > > off there would be a 'lack of signal'. However I'm not quite sure how
> > > > to signal from there to the house (50 yards maybe). I don't really
> > > > want a whole WiFi connection just for an on/off indication. Can one
> > > > get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> > > > sight to one of my WiFi routers so that should be OK. What's the
> > > > minimal sort of device for saying "I'm alive"?
> > >
> > > Add some sort of wifi gadget, powered from the same power as the fence,
> > > then set up your laptop to ping the gadget at regular intervals.
> > > PingInfoView can do that, and sound an alarm, send you an email, when
> > > the pong fails.
> > >
> > > The 'gadget', could be a Smart Plug, IP camera, old wifi router, old
> > > wifi capable phone - anything which has wifi capability.
> >
> > Yes, I think this may be the best answer. I have a couple of WiFi
> > enabled microcontrollers that should do the job. I'm just trying an
> > ESP32 based one and it seems to be possible, I'm not quite sure about
> > the range yet.
> >
> The range is the issue, nothing like what I need even with
> line-of-sight between router and the ESP32 microcontroller. If the
> range was OK it would work perfectly, so maybe I need to find an ESP32
> board (or similar) with an aerial.
>
There are some very low cost vhf and uhf radios that could be made to do what you
want. For example,
https://www.ebay.co.uk/itm/295699300577
There are lots of other suppliers of similar products. The vhf versions are likely
to have longer range than the uhf ones.
John

John Walliker <jrwalliker@gmail.com> wrote:
> On Thursday, 23 November 2023 at 21:18:07 UTC, Chris Green wrote:
> > Chris Green <c...@isbd.net> wrote:
> > > Harry Bloomfield Esq <a...@harrym1byt.plus.com> wrote:
> > > > On 23/11/2023 09:33, Chris Green wrote:
> > > > > The fence energiser is mains powered and in a building visible from
> > > > > the house, something very simple and mains powered would do the job as
> > > > > it can simply be powered from the same socket as the energiser, when
> > > > > off there would be a 'lack of signal'. However I'm not quite sure how
> > > > > to signal from there to the house (50 yards maybe). I don't really
> > > > > want a whole WiFi connection just for an on/off indication. Can one
> > > > > get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
> > > > > sight to one of my WiFi routers so that should be OK. What's the
> > > > > minimal sort of device for saying "I'm alive"?
> > > >
> > > > Add some sort of wifi gadget, powered from the same power as the fence,
> > > > then set up your laptop to ping the gadget at regular intervals.
> > > > PingInfoView can do that, and sound an alarm, send you an email, when
> > > > the pong fails.
> > > >
> > > > The 'gadget', could be a Smart Plug, IP camera, old wifi router, old
> > > > wifi capable phone - anything which has wifi capability.
> > >
> > > Yes, I think this may be the best answer. I have a couple of WiFi
> > > enabled microcontrollers that should do the job. I'm just trying an
> > > ESP32 based one and it seems to be possible, I'm not quite sure about
> > > the range yet.
> > >
> > The range is the issue, nothing like what I need even with
> > line-of-sight between router and the ESP32 microcontroller. If the
> > range was OK it would work perfectly, so maybe I need to find an ESP32
> > board (or similar) with an aerial.
> >
> There are some very low cost vhf and uhf radios that could be made to do what you
> want. For example,
> https://www.ebay.co.uk/itm/295699300577
> There are lots of other suppliers of similar products. The vhf versions are likely
> to have longer range than the uhf ones.

They look useful, even if not for the present requirement, thank you.

--
Chris Green
·

On Thu, 23 Nov 2023 09:33:11 +0000, Chris Green <cl@isbd.net> wrote:

>The fence energiser is mains powered and in a building visible from
>the house, something very simple and mains powered would do the job as
>it can simply be powered from the same socket as the energiser, when
>off there would be a 'lack of signal'. However I'm not quite sure how
>to signal from there to the house (50 yards maybe). I don't really
>want a whole WiFi connection just for an on/off indication. Can one
>get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>sight to one of my WiFi routers so that should be OK. What's the
>minimal sort of device for saying "I'm alive"?

Two solutions:

<https://www.patura.com/App/WebObjects/XSeMIPSPatura.woa/cms/page/locale.enGB/pid.102.104.954/agid.45.52.57/ecm.ag/Blitzlicht.html>

Flashy light powered by the fence itself. So it shows the fence -- good because
what good is power to the fence if it's shorted out? It's cheap, simple,
measures th eimportant part, but you need to look at it.

<https://www.patura.com/App/WebObjects/XSeMIPSPatura.woa/cms/page/locale.enGB/pid.102.104.954/agid.45.46/ecm.ag/Alarm-Devices.html>

Bunch of alarm devices, pricey, but send stuff to your phone via GSM, or measure
fence voltage and upload it.

Prices disapper when set to UK, but this

<https://www.patura.com/App/WebObjects/XSeMIPSPatura.woa/cms/page/locale.enGB/pid.102.104.954/agid.45.46.3796/ecm.ag/PATURA-Farm-Network-Zaun-%C3%9Cberwachungsstation.html>

is 189 € incl. 19% VAT.

Thomas Prufer

I was going to suggest a laser light pen customised to work off a psu, you
could even have a photodiode receiver set up to look for the beam. A torch
might not be bright enough to be seen on a sunny day. Many years ago they
used to make intercoms that worked over the mains wiring and on some you
could lock down the speak/call button. The other unit would be needed to
receive the signal of course.
I guess these are probably too low tech for today.

Brian

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<nothanks@aolbin.com> wrote in message
news:ks8m3gF273fU1@mid.individual.net...
> On 23/11/2023 09:33, Chris Green wrote:
>> I want to know if something (an electric fence) is turned on and I
>> don't particularly want to traipse out to the shed where the fence
>> energiser is to check.
>>
>> It gets turned on and off throughout the day as different people go in
>> and out to check their horses so there is always a fair chance that it
>> might not get turned back on, especially if visits overlap.
>>
>> So I'm wondering how I might rig up some sort of remote indicator that
>> will let me check whether it's on or not. Ideally it would be
>> possible for a computer to monitor it as I could then have an alarm of
>> some sort if it was off for, say, more than an hour.
>>
>> The fence energiser is mains powered and in a building visible from
>> the house, something very simple and mains powered would do the job as
>> it can simply be powered from the same socket as the energiser, when
>> off there would be a 'lack of signal'. However I'm not quite sure how
>> to signal from there to the house (50 yards maybe). I don't really
>> want a whole WiFi connection just for an on/off indication. Can one
>> get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>> sight to one of my WiFi routers so that should be OK. What's the
>> minimal sort of device for saying "I'm alive"?
>>
> A cheap LED torch fixed to the shed and pointing at the house. Switched on
> with a relay whenever the supply to the fence is off. Add a timer to make
> the torch flash after an hour.
> Alternatively (and more expensively) there are several GSM-based "phone
> home" devices that can be configured to call your mobile. Search for
> <mains power failure alarm> or similar

As long as he does not have too many short horses. Electric fences do not
always work as many pulse and are not very good att the furthest point.
Brian

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"Tim Lamb" <tim@marfordfarm.demon.co.uk> wrote in message
news:3sXgAMDndyXlFwSz@marfordfarm.demon.co.uk...
> In message <nri33k-vrrp2.ln1@esprimo.zbmc.eu>, Chris Green <cl@isbd.net>
> writes
>>I want to know if something (an electric fence) is turned on and I
>>don't particularly want to traipse out to the shed where the fence
>>energiser is to check.
>>
>>It gets turned on and off throughout the day as different people go in
>>and out to check their horses so there is always a fair chance that it
>>might not get turned back on, especially if visits overlap.
>>
>>So I'm wondering how I might rig up some sort of remote indicator that
>>will let me check whether it's on or not. Ideally it would be
>>possible for a computer to monitor it as I could then have an alarm of
>>some sort if it was off for, say, more than an hour.
>>
>>The fence energiser is mains powered and in a building visible from
>>the house, something very simple and mains powered would do the job as
>>it can simply be powered from the same socket as the energiser, when
>>off there would be a 'lack of signal'. However I'm not quite sure how
>>to signal from there to the house (50 yards maybe). I don't really
>>want a whole WiFi connection just for an on/off indication. Can one
>>get a sort of WiFi 'beacon' that simply says "I'm here"? It's line of
>>sight to one of my WiFi routers so that should be OK. What's the
>>minimal sort of device for saying "I'm alive"?
>
> Going sideways.... I assume the visitors have to crouch under the fence
> for access. Could you install a gate and have the fence wire routed across
> above head height.
>>
>
> --
> Tim Lamb

Brian Gaff <brian1gaff@gmail.com> wrote:
> As long as he does not have too many short horses. Electric fences do not
> always work as many pulse and are not very good att the furthest point.
>
You're welcome to come and touch our electric fence at its furthest
point! The energiser is supposed to be able to drive over 50km of
fence and we have only a fraction of that.

--
Chris Green
·