I’ve been considering a sensing magnet for a while, mostly idle musing but now a bit more seriously, and am curious, what can a sensing magnet sense? Can it detect a Qi wireless charging pad? An induction stove? Can you really “hear” music through it with a Lodestone Pico, or just tell that there is something vibrating there? Anything else that will surprise me when I feel it for the first time?
Adjacent to this, for fear of having to remove it for an MRI or something, what is it like to have a magnet removed? I’ve heard that having a magnet for a while starts to develop a sense like any other, and if I suddenly lost one of my normal 5 senses, I’d definitely notice and feel very weird for a while after. Is it the case with this, or easier to cope with?
Thanks for your help, and if there’s a thread I’ve missed with these questions already asked and answered, sorry about that, I tried to look for them ahead of time and must have failed
No. You will only really feel AC not DC, and it has to have a high current. The magnet has to move for you to feel it. Kind of like a speaker. If it gets pulled back and held, you won’t hear a thing. If it moves back and forth, you’ll hear a tone. Same concept.
Yes absolutely if you place things right
You can feel it now if you have a very small but strong magnet and a few different large power bricks (ie laptop brick) 
I don’t have experience loosing a magnet, and I’ve only had mine (xG3 v2, L1) for 99 days, but I don’t notice it much. Every once in a blue moon I’ll walk past something “spicy”, and I’ll feel it flutter, but 95% of the time that I do feel it, it is on purpose (ie inappropriately touching the microwave at work). I wouldn’t put this on the same level as loosing, say, your sense of smell, but closer to your sense of humidity (a subset of touch). 95% of the time, most people don’t walk into work in the morning and go “damn, it’s dry in here”. They just notice their fingers are starting to crack near their nails halfway through the day, ‘feel’ the air for a second, then notice that it’s dry. Does that make sense?
Wireless charging is DC? Can you have DC induction like that?
All I know is I’ve never felt a wireless charger with my magnet. Granted I’ve only tested crap-o-matic 10w offbrand ones.
If someone has felt a qi/similar charger please correct me and point me to the model.
Nope. It’s the building and collapsing fields when the poles flip that make the magic happen (as i understand it). Although a prolonged, steady DC discharge will cause a buildup of static electricity.
2A if we’re talking 5v–not exactly high draw.
Also the frequency is between 150khz and 400khz so good luck feeling that
I’m not entirely sure that that’s the voltage you’d find across a Qi charger coil, and the multiple turns could help in theory…
However:
Anyways, I can’t sleep and I’m answering questions that have already been answered…
But better! I always appreciate learning more from you.
Hopefully sleep comes soon.
You use primarily Meissner and Pacinian “corpuscles” as mechanoreceptors for vibration which are tuned around 20-50Hz and 200-300Hz respectively, so anything in the kHz range is not gonna work out.
50/60Hz AC works great though. Take a tiny magnet and rest it on your fingertip, then bring it close to the side of your microwave oven with the controls while it’s running and you’ll see.
You can hear from like 20Hz~15kHz though (but anything above ~3kHz will be too dampened by your tissue) so if you stick the magnet finger in your ear you can hear any sound signal produced by a coil pretty well
I smell magnets 
Yes absolutely if you place things right
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Let me clarify. After a few times you will have the illusion of hearing tones when sensing one.
Songs require a whole lot more training. You can easily recognize one you know well but “hearing” it a whole other story and will take some brain re-wirinh work.
Yup that translates to a decently sensitive range of 0-400Hz with a steep falloff after that. The peak is around 200.
(The sensitivity curve is different for different shapes of signals. And you can tell them apart too)
Library (and some store) anti theft systems, they’re surprising for sure 
Big transformers around trolley stations
Induction stoves yup
Yes. Probably easier because you don’t rely on it as much and it’s relatively new.
Before I got a magnet I never thought I’d stick my finger in so many ears
I haven’t felt a charger, but have definitely felt DC through large gauge wiring as apart of a solar/battery system if that helps…