When I dare to use an
A) electric blanket, or a electric frying pan set on "low",
at the same time when there is a
B) UPS computer power supply, or Ham radio power supply
also turned on anywhere in the house, the power supplies hum most
worryingly. One must make a choice: A) food, warmth, or B) fun.

What is the name of this waveform resonance with the current limiters
of A phenomena? Is there some kind of filter I can apply?