I am working on a monitoring system for local farmers who are using an electrical fence to keep wild hogs and deer out of fields. The electric fence has a single energizer on the fence. The energizer is outputting 6-12K VAC for 400ms every 1.3 seconds, and I am needing to read this voltage. When I accepted the project, I thought the system was working on DC which I already have a system that will read that. I have made a voltage divider to set that voltage down the where I'm working with a 1:10 scale. I can't seem to find a way to read something that is only active for 400ms. Does anyone have any ideas?

 

There is a company called Dranetz that makes instruments for measuring and recording transients on high voltage power systems.

The output of a fence charger is very high voltage (like an ignition coil), but very little current. What is your objective in reading this output?

 

What exactly do you need to know?

The easiest way to know if the fence is working is to put a old automotive spark plug gapped really wide,(~.100") at the very end of the fence and see if it fires off.

If its popping the whole fence is working. If not then something needs fixing!

 

There is a company called Dranetz that makes instruments for measuring and recording transients on high voltage power systems.

The output of a fence charger is very high voltage (like an ignition coil), but very little current. What is your objective in reading this output?

So the customer has 8 systems around his crops. Right around 150000 feet of fence. He has to have a guy ride the whole line every day and possibly twice a day depending on weather. So my company makes a monitoring telematics system for irrigation and we are wanting to adopt our system in the fence monitoring market.

 

What exactly do you need to know?

The easiest way to know if the fence is working is to put a old automotive spark plug gapped really wide,(~.100") at the very end of the fence and see if it fires off.

If its popping the whole fence is working.
If not then something needs fixing!

What I need to know is when the fence starts outputting <7K V I want to get an alert. So I need to read the voltage and input into my monitoring system.

 

I see.

As others mentions you will need a resistance divider for high voltage to bring the fence voltage down to a level your electronics can work with.

It shouldn't be all that hard. Just a few high voltage high ohm resistors in series to divide to make something like a 1000:1 divider so your electronics would only see around 12 volts at a 12,000 volt input. The rest of the circuit would just be made up of a comparator to trigger a high or low output stage that goes to your other monitoring systems.

 

A neon bulb in series with the high voltage divider should also give a visual indication of the line's operation (at least whether it's shorted or not).