Magnetic Sense Trainer

edited February 2015 in Magnets
I started working on a magnetic sense trainer today. It is pretty cool to play about with so far.  I did a write up on my blog here: 

It still needs some tweaks and polish, but if there is interest I can get the design refined and get a bunch manufactured at work.
let me know what you guys think.


  • I think this is a great idea, especially for those of us lacking in every day exposure to things the implants would respond to. I'd support this.
  • That good sir is brilliant
  • Nice, put it in a box and sell em. I'd buy one for sure
  • do you guys think it would be better to use a power supply or batteries? I'm thinking power supply because batteries would get expensive quick with it running on 2 9v's but It works with ipods, phones and such already so I don't know if someone would want it portable. 
  • Fantastic idea ... Count me in for one please.
    Don't mind either way regarding batteries or power supply. Love the idea of being able to use it with my phone, though.
  • I would LOVE to get my hands on something like this. It's been interesting trying to figure out what's a genuine reaction vs what might be just in my head, especially when it comes to feeling current.
  • @Raven That's almost exactly what Osteth designed :) even uses the same IC
  • yeah it's pretty much the same thing
  • I found it when I went on amazon to find the IC :)
  • There are also signal generators available for Android (and I would assume other smartphones as well) for free download. 

  • Will different coils respond best to different frequencies? 
  • I would personally like it to be portable. To use when bored somwhere
  • edited August 2014
    @raven, Yes different coils will work better or worse, results will be based on the pairing of the large cap and the coil mainly. I am currently working on generating a board design and gerbers for this now so that I can get one set up on the spectrum analyzer and get some measurements.  I want to bring the phase noise down as low as possible so that what is being felt is exactly what you are injecting. the way I see it, It would be worthless to train your sense to an incorrect or unknown frequency.  so I am attempting to make this extremely precise.  The quick and dirty way I made my coil for the prototype was to wrap enamel wire around a 9v.  once I get the design a bit more polished I will calculate out what the induction value should be for the coil and let you all know. the easiest way to get a voice coil is to take them out of speakers. 

    I got to thinking and figured why decide on how to power it and just make it so it can be powered by either. so the next iteration of the design will have battery of outlet power. 
  • After getting a request to get off my ass and make these trainers I just ordered the parts to make 4 trainers.  I was waiting to save up cash to get a decent sized batch built at work. but I am just going to go ahead and stat hand building them instead.  parts will arrive Nov. 7 and Ill start building them then.
  • could this work if you made the coil into a bracleet and ran it off a 555 timer if all you wanted was a variable square wave
  • yeah, that should work fine. 
  • Any update on the project? @Osteth
  • I have yet to do the math @Osteth however wouldn't it require a lot of power to be able to handle any sort of decent duration from a bracelet location to reach the finger?

    Currently I am working on a similar yet slightly different project as well involving the coils and bluetooth and from what I have seen a small enough power supply to fit within a bracelet shape would not last long enough to finish a duration of a song unless I am missing something.
  • @Proxy: Have you given any thought to the idea of a wrist magnet?
  • @drew I have however for my current project having it on the wrist would not help me out as I plan on going off the previous thread and creating a bluetooth system that way I can have conversations over the phone. From how it is looking thought having the coil on the wrist does not look feasible unless I change a lot of how it operates around.

    As far as the wrist magnet what did you have in mind as far as the uses besides it being another location to sense things?
  • @Proxy: Actually, putting a coil on the wrist isn't that unfeasible. You're essentially building a Bluetooth headset, no?

    When you say "conversations", what do you mean? Actual audio?
  • @drew correct I am building a headset that instead of a speaker uses a coil and my magnet that is in my ring finger and instead of it sitting on my ear I instead bring the magnet up to my ear and press against it. When I say conversations I mean it plainly as that. Actual audio indeed. While it may be lower quality compared to anything in the practical sense it will be audio nevertheless. 

    While I could put a coil on my wrist the 8inch difference from my wrist to finger tip will either require a lot of power to force the frequency to hit my finger magnet with any decent output from what I understand and have been researching.

    Majority of this has already been posted in the portable bluetooth speaker thread and I am just working from the ground up learning as I go and testing out with all the goodies that my school so generously offers up in their labs.

    For this thread though I planned on poking the mind based around a sense trainer instead of looking for the other topic in the other thread. Like I had just mentioned though, I am still learning as I go and while I can soak up loads of information rather quickly I am aware that I am still missing out on plenty of details and knowledge that would probably make me walk in circles at some point.
  • If you had a microphone on one or more of your fingers, and recorded the sound of rubbing various different textured surfaces,

    and then played it through this coil loop, would the magnet vibrate in a way that made you feel as though you were touching the surface that recorded the sound?

    It would be interesting if so.

  • @ChilliEye the basic idea is a good one. In practice it will probably fail (I'd be very interested in the experiment and outcome tho). Reason is, the fingertips recognize the texture of a surface by the vibration caused when the groves and bumps of the finger surface slide over it (so far it lines up with your idea). Reason for it to fail is that the vibrations generated and picked up by the mechano-receptors are limited to a very small area. Or in simpler words, your fingers are like a high-resolution-vibration detector. The magnet would be able to reproduce the vibration, but not at high resolution but as a single huge area.
    The approach itself is quite awesome, just needs higher resolution in recording and reproduction. This could be a great way to improve augmented or virtual reality by adding a true touch sense. iirc I once read about a special display device for such things. It used high voltages and capacitive coupling to tingle neurons in the fingertips as the finger was sliding over the surface.
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