Method and apparatus for testing magnetic heads and hard disks

摘要

A method and apparatus for start-stop testing magnetic heads and hard disks in real disk-drive environment is provided. The tester has essentially the same dimensions as a conventional disk drive so that rotation of the disk pack inside the tester housing generates the same aerodynamic conditions as in a real disk drive. An accurate head positioning system, the operation of which does not depend on the deterioration of the magnetic conditions of the head and disk, is located inside the tester housing, and the friction and sticking forces can be measured till the moment of physical crash inside the housing. An essential advantage of the tester of the invention in that the measurement and positioning systems are combined into a single unit. The aforementioned combined system is based on the use of a Hall-effect sensor attached to the voice coil of the type used in the disk drive. Friction forces between the magnetic heads and the disks are measured by utilizing a voltage applied to the voltage-to-current converter.