Someone recently was discussing places to salvage motors from…I recently found a VERY beat-up portable CD player. Checking it out, to see what I coukd salvage from it, I found it had 2 small DC motors. Both run on 3 volts or so ( the box was powered by 2 AA batteries); the spindle motor (that spins the disc) is sort of a chubby pancake affair, the positioner (moves the laser diode and pickup in and out) is a long thin job, about 1/2" dia. x 1 1/2" long. Not sure what they’d be good for, but in this case, they’re free…
Someone also mentioned motors in .old computer disc drives – 5 1/4" floppy drives have a DC spindle motor.It runs on a 12v. supply, by way of a speed regulator circuit that keeps the speed constant. That could be done away with; just don’t connect the tach output to anything (the motors have 4 leads; 2 are the motor proper, the other 2 are a feedback tach signal that goes to the regulator. You could experiment by applying 6-12 volts to leads, 2 at a time, until the motor runs).
The positioner motor in these drives is a stepper; there are circuits available on this Forum and elsewhere for driving them, but that’s a lot more complicated than the straight DC motors.
I’m not sure about 3 1/2" floppies, but I suspect their spindle motors are DC, too.
If you are referring to floppy disk drives, some are some are not.
If you are referring to hard disk drives; you are way off base. All 5¼" and smaller hard disk drives have 3 phase brushless DC motors. There maybe as many as nine wires for these; 3 for power to the windings as a minimum, additional contacts are: center tap, ground, +5V input, three for the Hall sensor outputs. Modern hard disk drives have only three wires to the spindle motor, with the controller sensing the BEMF to determine when to switch the windings on.
Brushless DC motors are more common than straight DC in current computer related equipment. Brushless DC motors require a sophisticated controller.
the only problem is finding a 3 volt power supply without having to convert back to the AA batteries again…you might be able to find a 5 volt supply and put in a resistor in series in the line to get it down to a 3 volt supply but resistors get pretty hot dropping the voltage that much…chuck
You could build your own 3 volt power supply. It’s just the same as building a throttle. Check out this throttle design: http://home.cogeco.ca/~rpaisley4/TTRThrottle.html. Substitute an LM317 for the LM350K (1.5 amps output instead of 3 amps) and you won’t need D3 and D4. Adjust R2 until you get 3 volts output, then remove R2 from the circuit, measure its resistance, and replace it with a fixed resistor of the closest standard value. Or you could use the equation the author gives to calculate the value of R2.