Arduino Resetting Itself with Relay

Hello I am also looking for some help on this. My setup is a little different. I’m using two relays to alter the direction of a dc motor. I aswell get the Arduino resetting when turning off relay. See photo for how the relays are withered up. I am just looking for help on where to put the Diode on my set up. Any and all help is welcome.

I would use a full wave bridge rectifier sized to the motor’s voltage and stall current, which is?

Looks like the motor is 24v 5a. Thannks for the help so far!!!

Outsider!!! Your amazing. I had a flat rectifier rated for 4amps. Hooked it up and problem solved. Thanks so much!!!!!

FYI. This is what I am building

BryanX: Hello, I am facing the same issue with switching off aquarium water pump with relay. Thinking of buying the rc snubber from this aliexpress vendor. Is it suitable and how do I connect it to the relay?

Please help.


You have to connect it in parallel across the relay contacts .

Thomen: Hi I have a similar relay operating a 12v pump my arduino resets when it shuts off.. I was hoping to learn how to work out which parts I need to use to create a snubber.. my relay has the 12v power source + the positive terminal of the pump I'm running in it.. so would I connect the snubber across those 2 lines?

hi.. have u solved ur problem.same problem i facing with a 12 volts pump.when relay is turned off ardunio resets.please let me know how u solved the problem in your case


Could you take a few moments to Learn How To Use The Forum. It will help you get the best out of the forum in the future. Other general help and troubleshooting advice can be found here.

Hey dc42. I came across this post the other day when researching how to deal with the problems caused with shutting off a 240V fan (LCD printing nonsense, Arduino freezing…).
I didn’t know the fan wattage and didn’t know where to start. Your suggestion of 0.1uF in series with 100 ohms did the trick!
Just wanted to let you know that 7.5 years after you gave that advice, it’s still helping people.
Thanks, from New Zealand

Thanks for letting me know!