Electric Fence monitor

Discussion in 'The Projects Forum' started by Laserman4, Aug 9, 2015.

  1. Laserman4

    Thread Starter New Member

    Aug 9, 2015
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    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?
     
  2. Glenn Holland

    Member

    Dec 26, 2014
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    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?
     
  3. tcmtech

    Distinguished Member

    Nov 4, 2013
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    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! ;)
     
  4. Laserman4

    Thread Starter New Member

    Aug 9, 2015
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    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.
     
  5. Laserman4

    Thread Starter New Member

    Aug 9, 2015
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    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.
     
  6. tcmtech

    Distinguished Member

    Nov 4, 2013
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    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.
     
  7. crutschow

    Expert

    Mar 14, 2008
    16,554
    4,466
    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).
     
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