18678645. METHOD OF OPERATING HARD DISK DRIVES, CORRESPONDING CONTROL CIRCUIT, HARD DISK DRIVE AND PROCESSING DEVICE (STMicroelectronics International N.V.)
Contents
METHOD OF OPERATING HARD DISK DRIVES, CORRESPONDING CONTROL CIRCUIT, HARD DISK DRIVE AND PROCESSING DEVICE
Organization Name
STMicroelectronics International N.V.
Inventor(s)
Michele Boscolo Berto of Milan (IT)
METHOD OF OPERATING HARD DISK DRIVES, CORRESPONDING CONTROL CIRCUIT, HARD DISK DRIVE AND PROCESSING DEVICE
This abstract first appeared for US patent application 18678645 titled 'METHOD OF OPERATING HARD DISK DRIVES, CORRESPONDING CONTROL CIRCUIT, HARD DISK DRIVE AND PROCESSING DEVICE
Original Abstract Submitted
A voice coil motor (VCM) in a hard disk drive is operated in a discontinuous mode with an alternation of on and off times. A drive current to the VCM is facilitated and countered with a variable voltage across the during the on-times and off-times. The intensity of the drive current is controlled as a function of a Back ElectroMotive Force (BEMF) of the VCM. A method includes sampling during the alternation of on-times and off-times first and second values of the voltage across the VCM. The first value is sampled at a first time in response to the end of the off-time. The second value is sampled at a second time in response to the drive current of the VCM zeroing following the supply of drive current to the VCM being countered during the off-time. The BEMF is calculated as a function of first and second values.
