@rw
Nothing like that out will charge your watch while its on your wrist

@bonifartius yes magnetic field decay exponentially.. no it wont require exponential power.

The energy put into a magnetic field is recovered each cycle, presuming of course you design the device to not radiate into the far-field (which isnt really going to happen at the frequencies these things operate at the size of the pads).

so while you do need more instantaneous current/voltage to produce a bigger field, that is almost fully recovered and doesnt actually cost you anything.

Basically in technical terms when it isnt charging something it costs you now "real power" but exhibits what we call "apparent power"

@freemo yeah, with physics i only have what in german is called "gefährliches halbwissen" (rough translation: "dangerous semi-knowledge") 😜

@bonifartius We would say "He has just enough knowledge to be dangerous." I wouldn't be surprised if it comes from the germans.

Always cracks me up how all our sentance-long phrases boil down to a word or two in german :)

@freemo may be interesting if you don't know it already: https://en.m.wikipedia.org/wiki/The_Awful_German_Language

@freemo @bonifartius amusingly, knowing just enough to be dangerous used to mean the opposite. it used to mean you knew just enough to be a worthy opponent to experts but weren't quite an expert. at some point it was flipped to mean you only know enough to hurt yourself.

@icedquinn

Interesting and not surprising.

@bonifartius