Instructables

Can I run a hard drive motor without additional drive circuitry?


anjoze10 months ago

http://www.instructables.com/id/Run-HDD-spindle-motor-using-IC-555-4017-L293D/

No, they are brushless DC motors, and need special control chips.
i know this is an old topic, but what about dc fans for your computer? could i use the circuitry from one of those to power a hdd motor?
Panchi (author)  steveastrouk5 years ago
Thanks Guys! Its such a nice motor that I can't get myself to throw it away! Any suggestions for a simple circuit? Or can I use it for a small (tabletop) windmill?
zholy5 years ago
You could - THEORETICALLY, but not practically !!! I was trying to do the same, like you asked ... and a realised, that you would have to power up each coil differently in a order and then make it faster, so your rotor turns faster - that's almost impossible without the chip.

To understand that, try to put power in one coil - hold - and the rotor will probably move and stop in a fixed position related to the coil. And then, if you powered up a different coil - just by touching it (not holding) you would give an impulse for the rotor to turn. But if you held it, it would just move a bit and stayed still in the fixed position to the coil you are powering it up.
zholy is right, read my other comment. Its not practical, but it works.
Re-design zholy5 years ago
You can't even theoretically.  You have to have some extra circuitry.

The extra circuit doesn't have to be complicated but it does have to be able to sequence the coils in the correct order and a the proper frequency for the speed you want it to run.  And it has to be able to carry the current the motor takes.  A regular disk drive won't use much current so that should not be too hard to accomplish.
Panchi (author)  Re-design5 years ago
If it does not take much current can I use an AC voltage and introduce a phase shift using an electrolytic capacitor?
Stephen3044 years ago
SOLUTION!!! Its actually IS theoretically possible, heres a video of me doing it, though its very crude and cant be used in a big project, it doesn't work very well, but it works: http://www.youtube.com/watch?v=CWx5ji_sFUw
seandogue5 years ago
As has been said, the answer is quite simply

no.
You can reuse an old hard drive brushless motor in several ways.

1. You can use the original PCB that comes on the hard drive to power the motor. You will have to run a couple of wires to ground on some hard drive to trick the PCB in keeping the motor running. Some hard drive PCB's will allow the motor to spin continually and some will stop after a certain amount of time.

2. You can build a DIY BLDC drive circuit using nothing but a handful of transistors and a signal generator. Some have even done it with a handful of transistors and a 555 timer. There are more stable options but they are more involved.

3. You can rewire the motor with larger gauge wire and attach blades to it and use it as a generator. There are many tutorials on the net with step by step diagrams on how to accomplish this. You could even use it as a generator straight out of the hard drive but it will not supply that much current or voltage. You will be able to light a few LED's without any modifications but that is about it.

For those that say that you can not reuse a hard drive's brushless (BLDC) motor for anything easily, they are sadly mis-informed or they just do not wish to learn, they do not know or they just want tutorials that explain everything because they can not think for themselves.
Keep searching. There is alot of information out there on what you were asking. Do not let others discourage you and keep you from experimenting.
I'd like to know just what the fk you're talking about Mr cosmos. Your insinuations are transparent and unfounded.

I have read no comments in these threads that is intended to discourage the original author from experimenting or in fact from using the motor.
Oh, well I never said you can't use them, I simply stated that you can't use them without additional circuitry. They do not run themselves.
joaojero4 years ago
Try looking for stepper´s motor.