I am reading through the excellent All About Circuits textbook, volume II. I see that sometimes other frequencies are put 'on top' of the mains 60hz, to convey information of interest to the power company across lines, or to carry data signals. I've heard of this being done before... but my question is, doesn't this affect the total power across the lines, or rms voltage? Won't this subject some household equipment to danger, due to this? And aside from this, don't some items rely on the frequency of the mains, as sort of a clock?
Thank you
Thank you