8 thoughts on “Macro video of a hard drive in use”

  1. Thanks for the link! I cut out the sound in the video because all that you could here was my air conditioner running and not the sounds of the HD.

    1. Brian,

      No matter, the quality of the video makes up for it! (Canon 5D, right?)

      I really enjoyed watching your videos – you had me drooling over the vane displays you found, and I see you have a nixie fetish as well! Very cool.

      Thanks for sharing. 🙂

  2. I’ve heard of people playing songs via the HDD, but never seen it 🙂

    Your little HDD laser sounds like fun… If it’s a mobile drive, 5V is correct. Ground one side of the VCM and drive the other will cause motion in one direction, ground the other side and drive will go the opposite way. You’ll need to build an H bridge to get bi-directional control.

    Flyback diode is probably a good idea, they can generate a strong inductive kick. Good luck!

  3. Hmmm Voice coil .. I’ve seen people using a HDD as speaker 🙂
    Anyway. I don’t want to try to read data I’d like to glue a little mirror on the arm for toying with lasers.
    So connecting the coil to a 5v supply and drive it with pwm through a transistor should work right? Do i need a flyback diode in such a setup?

  4. Oh and watch out, the resistance of each phase of the spindle is also similar to that of the VCM. Usually near the center of the spindle, under the hard drive there are 3, (possibly 4) connectors, for each of the 3 phases of the motor (plus possible center-tap). Do a continuity test between these connectors and the PCBA to HDD connector I mentioned above to eliminate them.

  5. The HDD arm is called a VCM (Voice coil motor), it’s not actually a voice coil these days but the naming has stuck. Sometimes it’s also called the servo.

    The coil is basically just a wire loop, R+L, sat between a pair of magnets, apply some differential voltage and you’ll get movement.

    If you take away the HDD’s PCBA (remove the torx screws) from the HDD assembly, you’ll see a connector underneath it, with 12 or so connections. Two of the those are connected to the VCM. You’ll have to “guess” which is which. The best method is use a multimeter to measure the resistance between 2 pins, the VCM connections should read 5-10 ohms.

    For desktop and enterprise drives, you should use 0-12V for your driving signal, 5V for mobile HDD’s. Try to keep it under 3A, should last for several minutes before the coil burns up. PWM’ing will keep the current down.

    Let me know if you have any more questions… I work on the Power/Controller IC’s that go into HDD’s 😉

    Very unlikely you’ll ever be able to read and write from the media though, complexity is very high for this.

  6. How could one move the HDD arm without the drive electronic connected? Or the other way around: can it be done with a raw microcontroller or do i need extra parts for driving? What kind of signal do i need to send to the coil and when does the coil get burned?
    Would be nice to get some insights 🙂

Leave a Reply to Chris Zeh Cancel reply