The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 2009
Filed:
Mar. 29, 2001
Mark Heimbaugh, Pleasanton, CA (US);
Mark Heimbaugh, Pleasanton, CA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
An apparatus for powering a voice coil motor retract circuit in a disk drive is disclosed. The apparatus allows a disk drive to power the voice coil motor retract circuit while also slowing the spinning disk. A DC-to-DC converter converts the back electromotive force from the spinning disk into voltage which drives the retract circuit. A feedback circuit controls the switching of the DC-to-DC converter based on the available voltage for performing the retract function. Importantly, the DC-to-DC converter allows the disk to be slowed while simultaneously providing power to the retract circuit. In one embodiment, the windings of the spindle motor are used as the inductor element in the DC-to-DC converter. The power MOSFETs associated with the spindle motor are used as the diode unit and the switch unit of the DC-to-DC converter. The power supply capacitor is used as the output capacitor of the DC-to-DC converter. The feedback circuit provides a fixed off time in which energy is transferred from the spindle motor windings into the DC-to-DC converter output capacitor, and a minimum on time in which energy is allowed to build in the spindle motor windings. A method for powering the voice coil motor retract circuit while braking the disk is also disclosed.