Would it be possible to 'erase' a magnetic multi-pole strip / sheet to 'record' a short piece of low fidelity music on it (using an electromagnetic head etc.) ? The resulting 'tape' is then expected to be 'played back' using a hall-effect sensor, much like a music box. Kindly note that this cannot use a standard cassette system for legal reasons.
What would be the feasibility of the above and any issues (magnetic or other) that one might face while doing so ?
Thanks.
What would be the feasibility of the above and any issues (magnetic or other) that one might face while doing so ?
Thanks.
I saw a magnetic recorder using iron wire, several decades ago. Quality was reasonable for speaking words, far from hifi. But it did its job.
Short answer, no.
It is a "hard" magnet (high coercitivity) , basically same as a speaker ferrite magnet, "square" hysteresis waveform, needs thousands of ampere turns to magnetize, then the opposite to magnetize the other way, the works.
No way you can record an "analog" signal there.
And even if it were "soft" magnetic material, it would not be better than regular magnetic tape.
Yes, Sir, thank you. By the way, my question comes from this video that I happened to see the other day, but maybe it's not as good as tape ...
Even I remember having read of something like that. Iron wire however should be heavier than emulsion tape.
A bare Hall effect sensor is far too large to use as a pick-up head - however you could fashion a magnetic loop to put it in with a thin gap as the pickup... Magnetic head gaps are measured in µm, Hall sensor chips are mm across... Getting the head out of an old card mag stripe reader might be one way to acquire a suitable head
@Mark Tillotson, I'd discarded the idea (as soon as I read JMFahey's post) however, for knowledge sake, isn't the flux path through the thickness of the chip (as shown below) as opposed to being across ? I found the picture in the following paper:
https://www.semanticscholar.org/pap...tera/dc7f5da723d0ca9da778238ecba8f5a381fa91e7
https://www.semanticscholar.org/pap...tera/dc7f5da723d0ca9da778238ecba8f5a381fa91e7
Yes in a Hall chip the current flows on one axis, Hall voltage develops in another, and magnetic flux is vertical w.r.t. the chip. Basically its the Lorentz force pushing the moving charge carriers to the side - any conductor displays a Hall voltage, but its easiest to measure in a semi-conductor as the charges move faster due to having a much lower density than in metals.