Gentlemen, no matter how far away they are in the house from each other, when I plug in
*Electric blanket (with sine wave chopping current limiter) + uninterruptible power supply, (attempt to keep warm and use a computer at the same time) or
*Electric frying pan (with sine wave chopping low power setting) + 12 V amateur radio power supply (attempt to cook something and not have to turn off a ham radio)
I get this terrible hum out of the latter of each, due to some kind of electrical resonance. Is there some kind of electronic filter one can use?
Each sine wave chopping device is just a LOW-MED-HIGH switch that does something funny to the AC wave form as a simple way of cutting down from full power.
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