high voltage voltage/current sensor

Discussion in 'General Electronics Chat' started by coinmaster, Feb 17, 2016.

  1. coinmaster

    Thread Starter Member

    Dec 24, 2015
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    Does anyone know of a voltage/current sensor IC that will work on voltages up to 600v?
     
    Last edited: Feb 17, 2016
  2. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Please provide more information -- What exactly do you wish to do?

    FWIW, Re: the described application - a 'CAT IV' optocoupler will provide adequate isolation pursuant to safety and equipment protection (see example device HERE) --- Of course a resistive divider (or other appropriate scaling/transformation scheme) will, nonetheless, be required...

    Again, higher quality responses require less ambiguous questions!:cool:

    Best regards
    HP
     
  3. coinmaster

    Thread Starter Member

    Dec 24, 2015
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    I need to accurately measure DC voltage and current in circuits with voltage ranges between -600v to +600v where the information will be fed to a microcontoller.
     
    Last edited: Feb 17, 2016
  4. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    It wouldn't seem that you need a special sensor? -- You need merely scale and 'offset' the level such that the anticipated extremes fall within range of the ADC input...

    Best regards
    HP
     
  5. DickCappels

    Moderator

    Aug 21, 2008
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  6. coinmaster

    Thread Starter Member

    Dec 24, 2015
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    I'm assuming you mean use a resistor divider on the input of the sensor? That would be great but I would need highly matched resistors and I can't seem to find any sensors that will measure negative voltage.


    I don't get it, aren't those meant for measuring AC on DC lines? How am I supposed to measure a 600v line with an opto anyway?
     
  7. DickCappels

    Moderator

    Aug 21, 2008
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    Oh...sorry, I made some assumptions which are apparently incorrect - Do you want to measure voltages ranging from -600V to + 600V and the current being drawn from that voltage source?

    Most likely Hypatia's Protege's suggestion will work. What do you want to do with the sensed voltage and current -take an analog voltage proportional to the sensed voltage and current, take a digital representation? Something else?

    Can you show us a drawing showing precisely what you want to do?
     
  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Just throwing this out there.. There are some "generic" interface circuits here..
    http://cq.cx/interface.pl

    I'm doing some voltage/current sensing (lower voltage) and I'm just using a voltage divider circuit for the voltage and a hall effect sensor for current measurement.
     
  9. coinmaster

    Thread Starter Member

    Dec 24, 2015
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    I'm feeding the measured voltage and current into a microcontroller so I can use it as a feedback mechanism for a high voltage digital potentiometer.
    All I need here is to be able to measure what the voltage and currents are without blowing up my measurement device.

    Unfortunately none of the ICs do negative voltage very much so I would have to use a high value voltage divider with precisely matched resistors and the the IC would have to be able to measure really tiny voltages when the voltage input is low.
     
    Last edited: Feb 18, 2016
  10. alfacliff

    Well-Known Member

    Dec 13, 2013
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    I have a digital volt meter that will handle those voltages safely, and has an rs232 interface to output its readings to a computer.there are also solid state osciliscopes with that capability. why not something like that?
     
  11. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Correct.
    Standard value resistors are available to (at least) 0.5% tolerance.
    Hence the requirement of 'offsetting' the scaled EMF such that the lowest anticipated excursion corresponds to a non-negative value (post translation)...

    Best regards and good luck!
    HP:)
     
  12. coinmaster

    Thread Starter Member

    Dec 24, 2015
    350
    6
    You mean use a resistor divider with a bipolar supply? Hmmm that could work.
     
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