Current Transformer Help

Discussion in 'The Projects Forum' started by Tahsina Hossain, Oct 13, 2015.

  1. Tahsina Hossain

    Thread Starter Member

    Jan 16, 2015
    40
    0
    Hi there,

    I need to use a current sensor CT-HX 3_50 in order to sense current of my inverter. I have never used a current sensor before so before going to a real circuit I am developing some test circuits. I know that the CT can go upto 3+-9 Amps and also that 4V is equivalent to 3 Amp? Now I am worried about the load, How to set it up? I mean I have no rheostat that goes up to 3 Amp. Also, I am not sure if I am constructing the circuit right. Attached are the circuit diagram and also the datasheets.

    Please help.

    Bests,

    Tahsina
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    The whole advantage of spending the big bucks for the HX module is that it should be calibrated out of the box, so shouldn't really need testing...

    For a wiring checkout, why not use it to measure the current drawn from the DC supply between the supply and the two DC-to-DC converters?
     
  3. Tahsina Hossain

    Thread Starter Member

    Jan 16, 2015
    40
    0
    Hi MikeML,

    Thanks a lot for your reply. when you say 'measure the current drawn from the DC supply between the supply and the two DC-to-DC converters' do you mean I can just directly measure the current from there without adding any kind of impedance? Sorry if this is a stupid question, I am just trying to understand how to build the circuit so that I don't blow up my current transducer.

    Also, I am trying to set up the test circuit as a part of my bigger project of load sensing and changing the switching frequency of the inverter based on the load current level and I will implement a MSP430 to do the coding and try to read current transducer output through MSP430.

    Thanks again!
     
    Last edited: Oct 13, 2015
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    The current sensor will measure the current flowing into pin5 and out of pin6 (i.e. through the sensor). I suggest temporarily using the current drawn by the two step-up converters as the test current.

    Hang a scope on pin4 (scope gnd on pin2) to see what the sensor outputs. Any additional load you hang across the +15V to -15V side of the step-up converters should increase the current sensor reading...
     
  5. Tahsina Hossain

    Thread Starter Member

    Jan 16, 2015
    40
    0
    Thanks a lot Mike, attached is the new diagram, Can you kindly check if I got your awesome suggestion right.

    I highly appreciate your time and help!!
     
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    No, dont do that!

    Loop.gif
    Do this:

    loop1.gif
     
  7. Tahsina Hossain

    Thread Starter Member

    Jan 16, 2015
    40
    0
Loading...