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4-20ma signal converter chip? — Parallax Forums

4-20ma signal converter chip?

LA6WNALA6WNA Posts: 138
edited 2013-12-18 14:40 in Accessories
Hello all.
Does any of you know about a chip that directly converts a 4-20ma signal into a , lets say 8-bits data value?
I`m gonna interface a 4-20mA industry pressure transmitter to a propeller project.
I know there`s a way to do it via a resistor in the current loop and then take the voltage over the resistor into a i.e. ADC0831, but I`m hereby looking for a chip with this feature built in.
Also, said the easy way; 4-20mA input and binary datavalue output. I dont even know if such chip is made at all, but maybe some of you guys do??

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2013-12-15 12:37
    I don't know of any ADCs with the resistor built-in. Measuring the voltage across a resistor is just the way it's done.

    -Phil
  • kwinnkwinn Posts: 8,697
    edited 2013-12-17 23:07
    Most electronics suppliers carry 250 ohm 0.1% resistors specifically to convert 4-20mA signals to a 1-5V signal for input to an ADC.
  • LA6WNALA6WNA Posts: 138
    edited 2013-12-18 14:40
    Thanks for reply folks. Yeah, guess the way to do it is with a 1-5v ADC and a resistor. Go for that.
    Wish you all a merry X-mas and a happy new Propeller-year 2014. Have fun.
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