I am trying to send a signal from the Arduino to a relay to open a switch. My problem is that my Arduino will be near the AC power lines.

I searched for how to prevent the noise to ruin the signal but every site and article was talking about how to secure the input data to my Arduino BUT my case is different as I am trying to send the signal from the Arduino to a relay.

How do I prevent the noise if there is any judging by the location of the Arduino ?

up vote 0 down vote accepted

You do not send a "signal" to relay as information that can get corrupted by noise from power lines. Your relay works because of a coil of wire, that becomes a temporary magnet when current flows through it, switching the circuit contacts.

Read here: http://www.circuitstoday.com/working-of-relays

Noise will not disturb switching the relay.

I hope you are using a transistor to drive the relay, not directly trying to drive it form Arduino. In that case all relays that require more power than a GPIO of Arduino can deliver, will fail. Also, use a flyback diode in your circuit.

  • The relay may not fail, but the arduino definitely will. – Hearth Oct 11 at 13:25

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