The Original Hard Drive Motor

This fascinating motor was based upon a rotor scavenged from an old computer hard drive. Hence as one would expect, it is almost entirely frictionless, and also very well calibrated. Between the dual hard drive platters reside 4 1/2" (12.7mm) square faced NIB magnets, fixed in place with high strength epoxy glue, at 90 degrees apart. The diameter of the hard drive platters (disks) is 130mm. The stator cores are made from permalloy (these were found to produce better results than relay cores). The dimensions of stator cores are as follows = 6x6x45mm. Each stator has 450 turns of enameled copper wire of 0.54mm diameter / 24awg.

Back Motors

In the above picture you can see the oscilloscope reading. The back EMF (cemf) was connected to the power supply (car / automobile battery 12 V). The duration of the pulse command and back EMF spike was measured on an oscilloscope, and as can be seen, the measured back EMF is a full 80% of the delivered pulse width, even using basic transistor grade switching parts! The motor runs at about 2800 RPM, and does so ABSOLUTELY COLD, as does the circuitry.

Pulse Width

—V ^ _


Back Erhf

The battery started with a rating of 12.38V

Then a load (the motor) was placed on it, and the battery voltage fell to 12.32V

After 2 hours the battery voltage rose to 12.35 V

After 20 hours battery voltage was recorded slightly lower at 12.32V

Then the battery was then disconnected

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

Get My Free Ebook


  • Tanja Beckenbauer
    How to power hard drive motor?
    6 years ago

Post a comment