I'm designing a project which consists of Arduino + long wires connected to buttons so I needed to test it and see how resistant it is to EMI. (Because the long wires can act as antennas).
I looked for material about this online but the only thing I could find was this link.
I tried what is suggested there but it did not work.
However in the process, by pure accident, I was able to create electromagnetic interference!
I have this old linear adjustable regulator and I realized when I plug it in and out, my PC speakers give out a very strong sudden noise. I figured this has to be EMI from the supply. So I hooked up my Arduino and my long wire to an input and voila! The input pin (even tho it had a 10k pullup resistor) would get triggered multiple times when I plugged the supply in and out of the AC outlet.
This was great news and I was able to test different filters.
Now I'm wondering what exactly is creating this EMI? (I'm assuming it's the transformer)
And how can I create a device that does this? Plugging in and out the power supply isn't very convenient and I'm not sure if it gets damaged in the process. So I wanna make a standalone device for this kind of testing in the future.
Also is it possible to change the strength and perhaps the frequency range of the EMI created?