I have been having ringing spike issues at the output of SMPS power supplies. I don't know what is this phenomenon is about but it is definitely related to switching devices on the same electrical network. When a switch or switching device is on the same electrical network. The switching device upsets the SMPS output. This is directly related to my previous question. Bu that time I didn't figure out the issue starts with SMPS output getting upset.
To demonstrate that I used a grinder as shown below:
And next to the grinder from the same power strip a 5V SMPS is powered.
Here is the output of the 5V power supply and the spikes "during" the short time the grinder is swithcing ON:
And here looks like high frequency ringing when AC coupled:
The problem is this power supply noise propagates through all sensitive devices it powers.
Does anybody have experience with such phenomenon? I even tried with EMI power line filter and isolation transformer but it didn't help. I guess SMPS already have filters at their input. Is there a way to filter out this at the power supply output? Would that issue happen with a linear supply?