Connect with us

Calculate Shunt Resistance

Discussion in 'Electronics Homework Help' started by inlineskater, Jun 16, 2012.

  1. inlineskater

    inlineskater

    13
    0
    Jun 15, 2012
    Question:

    To extend the range of a 0-8.4 mA, 46.3 ohm DC ammeter, what size of shunt resistor should be used to obtain a 92 mA range?

    Using the following formula:

    Ish/Im = Rm/Rsh

    Rsh = shunt resistance
    Rm = meter resistance
    Ish = shunt current
    Im = meter current
    ------------------------------------------------------------------------------------------------------------------

    Rsh = (46.3 ohms) (8.4 x 10^-3) / 83.6 x 10^-3

    = 3.8892 x 10^-1 / 83.6 x 10^-3

    = 4.65 ohms

    ------------------------------------------------------------------------------------------------------------------
    Could of I calculated this differently. Looking this it seems correct.
    ------------------------------------------------------------------------------------------------------------------
     
  2. john monks

    john monks

    693
    1
    Mar 9, 2012
    Yes. You can calculate the voltage needed for full scale meter deflection based on the current and resistance of the meter. With the current of the meter you can calculate the value of the current in the shunt resistance. Now you have the voltage and the current of the shunt resistor and now you can calculate the resistance of the shunt resistor.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-