That's really quite fascinating as a concept.
I think you mean as in rotating magnetic field areas of the disk in big chunks ?
Though, HDD's employ some very good shielding with their cases. Unless it was to run in cabriolet mode ? lol, top off, open to the sunshine.
Another way of using such a technique, may be to send the data to a DAC and on to a MOSFET or similar ?
As such, you could have all sorts of data trains feeding in, based on track number.
It would be similar to an old record player in function, or, I guess a CD, or even a function generator...but infinitely programmable.
The point being that if a certain wave was tweaked in the right way, you could alter it to be exactly at resonance with a transmitting coil or other circuit components. At exactly 50ms (or whatever) the waveshape could change to offset a null point. A regular square wave train of 0's and 1's would be just the same as a sig gen, but what if your HDD track snapped out to a sine wave mid way in the cycle.
Most would likely say to use a microcontroller for that, but, yes, reusing old tech is a great route and may set up mechanical resonances that were wholly unexpected..
Hmm, well I hope I have the idea somewhat right. Looking forward to more of your thoughts on it.
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