4-20mA Output current

Thread Starter

MihirGogri

Joined Feb 10, 2020
14
Hi,
In my project i am using accerelometer which is giving me output in the form various voltages. I want to send this voltages to other circuit which is kept 10 metre away. But the problem is the voltages will not travel such distance, so I have used XTR111 ic to convert this voltages to current. On testing this setup with 1-2m wires the current is proper but on oscilloscope it's showing noise, What can be done to get a clean signal?
P.S- For current to voltage conversion I am using RCV420, which is not giving me proper voltages.
 

strantor

Joined Oct 3, 2010
5,907
On testing this setup with 1-2m wires the current is proper but [...] For current to voltage conversion I am using RCV420, which is not giving me proper voltages.
How do you know the current is correct then?
. On testing this setup with 1-2m wires the current is proper but on oscilloscope it's showing noise, What can be done to get a clean signal?
Where are your probes as you measure this noise? The good thing about 4-20mA is its noise immunity. It can have "noise" on the line without noise in the signal transmitted, because the noise does not generate any current.
 

crutschow

Joined Mar 14, 2008
29,466
Your oscilloscope it likely grounded and measures the voltage not the current, which can have noise.
To detect the 4-20mA signal, you need a current sensor that does not ground the signal.
 

Thread Starter

MihirGogri

Joined Feb 10, 2020
14
How do you know the current is correct then?

Where are your probes as you measure this noise? The good thing about 4-20mA is its noise immunity. It can have "noise" on the line without noise in the signal transmitted, because the noise does not generate any current.
i have attached ammeter in series. one end is connected to the output of the xtr ic and other to 250 ohm resistor.
 
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