[cyphar]

Right, so there's no relative phase change between negative and positive terminals but there is a phase change between the terminals and ground (which can be interpreted as a frequency relative to ground)? And since I'm grounded I experience that frequency? Interesting. Is there a relation between the "float frequency" and the AC freqency? Is it the same because of how commutators work?

[_lm_]

I suspect that the float frequency is generally equal to the AC frequency, but I suppose it may be possible for it to be some subharmonic of the switching frequency, assuming you've got a switching power supply.