I've got a load of assorted brushless motors kicking around, pulled from old hard drives, video recorders etc. and I've noticed that they often have what appears to be a controller IC on the same board as the motor. However, I've looked up the part numbers, and looked around on the internet, and I can't seem to find anything out about them. Is it possible to use them for anything? I know that they're unlikely to have much torque, but they'd still be useful if they were usable. If not, How hard is it to make a basic brushless speed controller? from what I can gather, they put out three sine waves to the coils, each presumably a third of a cycle out of phase, but most people seem to reckon they're a pretty tricky thing to get working, so...?
One of them's in an old VCR head, and I was thinking of using it for a computer input for scrolling through stuff, or MIDI controll in a way similar to a monome arc. If I can get the motor going, I was contemplating using it to provide a bit of haptic feedback, but if not, I was wondering if it's possible to use the existing ring magnet on the motor casing with one or more hall effect sensors to provide the position sensing. How would I go about this? I'm guessing that you'd arrange about three of them around the circumference, but I don't know. Also, would this still work if the motor was used, or would the magnetic field from the coils mess that up?
Thanks in advance.