Using a stepper moter from a 3.5" or a 5.25" f

[Harry]

I would like to use a stepper moter from a 3.5" or a 5.25" floppy drive.<p>I would like to operate it by using either an on-off-on toggel switch or 2 momentary push button switchs.<p>I would like to make the moter turn 90 degrees to the left or 90 degrees to the right but always return to the center.<p>Can any one out there refer me to a circuit that I can use to do this with?<p>Harry

[Engineer1138]

Making a 90degree turn with a single contact closure will either require a microcontroller, or a whole lotta logic.
If you just want to build a circuit that does one step per button press that's much easier. I can't sent a schematic right now, but if this is indeed what you need, respond here or send me a PM and I can draw the schematic when I have a free minute. It can be done with 2 TTL chips and a motor driver chip and I know I have the circuit in my lab notebook.

[peter-f]

that would be using the large (unipolar) motor- driving the disk.<p>I'd like to find a simple driver for the bi-polar motor (driving the heads) as the helical drive would do much of what I want.
Is there something to get (say,) 5 or 10 revolutions from a center point (neutral position) and hold it there... or am I better off looking into servo motors?<p>[ March 01, 2005: Message edited by: peter-f ]</p>