Electronics > Beginners
How well would Floppy Disk film work as a micro-core transformer?
Tcll:
Those of you well versed in the area of solid state magnetic technology might be able to piece together what I'm trying to accomplish, but I don't wanna make it too painfully obvious. ;)
I'm wondering if it's possible to make basically a microscopic iron-core toroidal transformer like so that can retain it's magnetized state without power:
I can't afford to buy a gazillion iron cores, but I do have a ton of (probably 300 or so) unused trash-picked floppy disks stuffed under my bed and am wondering if the film for those would work for what I need.
or would the film be too restrictive to carry a proper magnetic current??
thanks :)
T3sl4co1l:
I mean, that's what disks are, they're core memory where the core spins past the winding(s). Can't you just use it as-is? :P
Good luck making discrete cores out of film, the layer is quite thin so mu_r and Ae will be very low.
Tim
Tcll:
--- Quote from: T3sl4co1l on December 30, 2019, 03:44:12 am ---I mean, that's what disks are, they're core memory where the core spins past the winding(s). Can't you just use it as-is? :P
--- End quote ---
that's the issue though, they need to be moving in order to even be charged...
at least I think anyways >.>
it's that motion that can be read.
in my case, I'm looking to induce a signal in the primary coil
and depending on the state of the toroid
if it works like I'd like it to
should induce a signal in the secondary coil on state change
but if it doesn't work like I'd like it to, it won't carry the field over to the secondary coil
if that's the case I may need to wind the primary coil over the secondary coil, and see if I can get a voltage spike on state change from a field collapse.
I don't have an oscilloscope to be able to test this
sure I have a linux PC, but I don't feel like DIYing a proper probe atm to plug into my sound card :P
EDIT:
note the test shouldn't be an immediate polarity switch
start with +- to set the primary coil with
then disable power
then enable power with -+ and see if you get a spike on the secondary coil
that is, if you have a floppy to rip apart anyways :P
Alex Eisenhut:
https://en.wikipedia.org/wiki/Bubble_memory
https://www.ebay.ca/itm/Intels-Bubble-Memory-and-ICs/223572383258?hash=item340df3d61a:g:iTAAAOSwzIZbthwc
T3sl4co1l:
You can still read floppy bits statically, you just have to separate the self-inductance from the media inductance. You wouldn't be able to use existing read amplifiers, of course.
Hmm, I wonder just how small of a difference that is. It might be 1% or less, which would be difficult to resolve on an oscilloscope.
Anyway, what you would see is, when you apply a slow pulse (more of a ramp) to the head, there is a corresponding voltage pulse, due to self-inductance. V = L dI/dt and all that. Somewhere along that slope, the bit flips (or not), and an extra hump of voltage (flux actually, so volts*time) is generated. You might put the head in a little H-bridge circuit (not much current is required, an analog switch I think would be okay?), so its polarity can be reversed easily, and that way you don't have to worry about positive/negative pulses being asymmetric, all your (new custom) R/W circuitry is consistent and repeatable.
You'd (obviously?) have a hard time also using the spindle motor as an indexer, so you'd need to replace that with a stepper to make single-bit seeks repeatable.
Tim
Navigation
[0] Message Index
[#] Next page
Go to full version