In industrial environments, we often get noise on the analog signal input to PLCs or other controllers. Motors, lousy wiring, etc., can generate noise.
Placing a 1- 100 uF capacitor on the input signal and ground (common to the cabinet) will reduce the noise the input receives.
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5 thoughts on “The Secret Of Getting Rid Of Noise On Your Analog Signal”
any sample putting some capicitor in the cabinent?
cuz i didnt get it. if how my supposed to do that in the real.
Whether we have to use capacitor in parallel with analog sensor?
Is it possible to use twisted wire for analog input instead of capacitor?
Twisted wire is a good idea for external noise along the path. Depending on the type of noise it will cancel it out due to the twisting of the wire. The capacitor will also try to filter this noise out in a more progressive manner. Try the circuit without and with the capacitor to see a difference.
How about for thermocouple inputs? Put the cap between the legs of the input or just the positive to ground? I think the second, but since both legs make the input, maybe one cap on each leg?
I have not done this with thermocouples but it can be done. You must have a long run to make before the controller.
Here is a post explaining how to do this with thermocouples.
Let me know how you make out.