cd drive motors

[samarsingla]

hi all
i recently opened an old cd rom drive. i was wondering what kind of motor was it that dove the cd rom. i should be some kind of stepper, waht is the nose it makes, like as if there were some bearings in that. how couls it be used?? please help if anybody has tinkered with it before....
thanx

 

[Nigel Goodwin]

The CD-ROM is spun by a DC motor, it may well be a brush-less one, likewise the sled motor is probably just a DC one as well - I wouldn't expect to find a stepper motor in a CD-ROM.

If you want a stepper motor?, try an old 5-1/4 inch floppy drive, they used a nice uni-polar stepper to move the heads. 3-1/2 inch drives aren't as useful, they usually use a smaller, less useful, bi-polar stepper.

 

[samarsingla]

shouldnt it then be having two wires coming out of it? it has thre a bit thicker and ten a bit thinner wires coming out of it. also three very small 4 legged ics are there. i cant see the exact configuration, can anyone please help clearing my doubts?
thanx

 

[zevon8]

The IC's may be Hall-Effect sensors to help determine motor speed on spin-up.

It has 13 wires connected to the motor ????? 3 or 4 , maybe 5 I could understand.

 

[samarsingla]

i am not sure how many wires go to the motor, some may go to ics only, maybe only three thicker wires are for motors, i am not sure, any suggestions?

 

[Nigel Goodwin]

i am not sure how many wires go to the motor, some may go to ics only, maybe only three thicker wires are for motors, i am not sure, any suggestions?

Yes, as I've already said - they won't be steppers - what use would steppers be?. If you REALLY don't believe me?, try turning them with your fingers - you will feel the individual steps on a stepper motor.

As I also said, they may be DC brush-less motors, which have more wires from the windings and sensors to the electronics controlling them.

 

[samarsingla]

that was what i tried first of all, i can feel the steps...

 

[Nigel Goodwin]

that was what i tried first of all, i can feel the steps...

Which motor?, and how many 'steps' can you feel per revolution?.

 

[Styx]

that was what i tried first of all, i can feel the steps...

The motor is a brushless DC and the "steps" you feel are the cogging due to to the surface magnets of the rotor finding a path of least reluctance with the stator (ie at the poles).