Hello all, Im wanting to add LoRa high voltage 0v to 10k or maybe up to 20k sensor/meter to monitor electric fences on the perimeter of a farm property. Is there any IoT LoRa battery powered sensors / IFTTT/home assistant compatible gateways that will read electric fence high voltage?
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I have been trying to develop one, on and off for the past couple years but running the farm always seems to get in the way 
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I have been using esphome to develop the esp8266 based solution. However I am having issues sourcing affordable ceramic resistors that are capable of dealing with these voltages and temperature extremes. I live in southern Ontario so I can get surface temperatures of 45°C to -40°C. If anyone has any ideas please share, maybe we can develop this solution for all us small ranchers and farmers.
3kV between every resistor?
You nailed it, use resistive voltage divider setup. I gather your design is from easy to gather parts versus special ohm resistors and wattage ratings.
Then feed that in to a voltage measuring circuit using ESPhome sensor
Wouldn’t it be easier to read the voltage going in to the transformer?
I’m not a farmer so excuse my ignorance here.
Or is the issue to make sure there is no break in the line?
Would a CT clamp work?
Is the idea to check if cell is charged or check if fence is intact?
That varies only from grid.
No, there is no current flowing in open wiring.
Not a common task, there are no “sonoff zigbee sensors” for this case.
Antenna and amplifier circuit could do it, I expect you can “hear” the fence with radio receiver.
Yes in fact farmers complained around here that DSL was screwed because of the noise from electric fences.
The difficulty here is not the sensor, but getting the data miles away, which is why the OP sensibly asked about LoRa. There are a number of threads here about LoRa, typically regarding mailboxes or garden sensors. The easiest way to integrate is probably https://docs.openmqttgateway.com/
Coupled with a small solar setup, for power.
This thread deals with LoRa programming. Awesome! LoRa Soil sensor
Or just buy an off the shelf high voltage probe and put its output to an ESP.
Did you build anything? Curious about what sensor you ended up using.
I too am looking for something similar to the LoFence but keep it local to just HA and use an ESP32 for my rotational grazing needs. I recently found this product, fencyboy, which happens to maintain a list of similar products in their documentation that might lead you to an off the shelf product.
I would assume a simple voltage divider be easy to add to an ESP32. Heck I would even be happy to use a WiFi version as my Unifi AP gives me good coverage on my property and neighbors’ properties, though LoRa would be preferred.
At 10-20 kV it’s less simple.
The LoFence git I linked above has electrical diagrams to reference.
I didn’t say it’s not doable. Just be aware that 20kV can break 10mm through air when you design your divider.
My fence zapper maxes at 10kV. It’s a pulse zapper with 5 Joules of output juice , not a continuous 10kV like Jurassic Park.
But yes it still hurts getting zapped with 5 J while accidentally holding a t-post.
What a disappointment… 
Just take care of the distances (arching) and voltage ratings of all components.
If the pulse is long enough, you should have no problem to detect it.
Ahhh arching. That must be why both the LoFence and FencyBoy have the voltage divider far away from the rest of the board.
It’s about 45 pulses a minute, give or take.
FencyBoy has a cool live dashboard where they are measuring 20kV:
https://app.datacake.de/dashboard/d/3c12e392-9fe2-40ce-94ee-14ddaaf07183
That’s not a problem, but pulse duration might or might no be…