About transferring 4-20mA to voltage

Dear friends,

I am working on reading 4-20 mA from Level/pressure/flow transmitters.
I used to use a 10 ohm resistor in series. so I measured the voltage drop on the resistor
but in this circuit I needed the ground from the transmitter device.
Is there a better method not using ground wire from the transmitter?

Parents
  • Electrical circuits always needs two signal traces for the poor electrons to flow continuously - with a single trace you can just charge some object until it gets the same potential after which the current will drop to zero.

    So if you then use one wire and a chassi ground or two wires depends on your situation with noise, distance, etc.

    If you do not want a shared potential, then you need to implement an isolated interface, where you might use some coupler (optical, magnetic, ...) before you return back to electrical signals.

Reply
  • Electrical circuits always needs two signal traces for the poor electrons to flow continuously - with a single trace you can just charge some object until it gets the same potential after which the current will drop to zero.

    So if you then use one wire and a chassi ground or two wires depends on your situation with noise, distance, etc.

    If you do not want a shared potential, then you need to implement an isolated interface, where you might use some coupler (optical, magnetic, ...) before you return back to electrical signals.

Children
More questions in this forum