Jeffrey A. Heydt - Oklahoma City OK David R. Street - Oklahoma City OK
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
A02K 2300
US Classification:
318254, 318138, 318439, 318778, 318798
Abstract:
Method and apparatus for accelerating a disc drive spindle motor from rest to a final operational velocity. During a low gear mode, the spindle motor is accelerated from rest to a first velocity through application of fixed duration drive pulses to the spindle motor. A high gear mode is next employed to accelerate the spindle motor from a first velocity to an intermediate velocity. Variable duration drive pulses are applied to the spindle motor each having a duration selected as a percentage of the duration of the most recently detected commutation period of the spindle motor. Once the spindle motor reaches the medium speed, commutation circuitry and back electromotive force (bemf) detection circuitry use detected bemf from the spindle motor to electronically commutate the motor to accelerate to the final operational speed.
Spindle Motor Initialization After A Control Processor Reset Condition In A Disc Drive
Jeffrey A. Heydt - Oklahoma City OK David R. Street - Oklahoma City OK
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
H02P 620
US Classification:
318254, 318431, 318459, 3889281
Abstract:
Method and apparatus for initializing a disc drive to bring a spindle motor to a final, operational velocity after a disc drive processor reset condition. The spindle motor is rotated using electronic commutation and back electromotive force (bemf) detection. Upon initialization of the disc drive, a control circuit checks for the presence or absence of detected bemf. The absence of bemf indicates the spindle motor is either at rest or is rotating at a relatively low velocity. In the absence of bemf, the electrical rotational position of the spindle motor is determined, a short braking pulse is applied to the motor, and rotation of the spindle motor is detected in relation to changes in the electrical rotational position. Further breaking pulses are applied until no apparent change in electrical rotational position is detected, after which the spindle motor is accelerated from rest to the final, operational velocity.
Detecting Head Landings On A Data Zone Of A Data Storage Disc
Jeffrey A. Heydt - Oklahoma City OK, US David R. Street - Oklahoma City OK, US
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
G11B021/02
US Classification:
360 75
Abstract:
Method and apparatus for detecting head landings on a data zone of a data storage disc. A disc drive includes an actuator which controllably positions a head adjacent a disc and nominally retracts the head to a parked position when the drive is deactivated. The actuator moves in response to current applied to an actuator coil immersed in a magnetic field. During disc drive initialization, the disc is accelerated to a velocity sufficient to allow the head to be aerodynamically supported over the disc, and current is passed through the actuator coil to urge the head toward the parked position. The current is monitored to detect generation of a back electromotive force (bemf) voltage induced by movement of the coil. An error condition is logged indicating that an initial position of the head was over a data zone of the disc when bemf voltage is detected.
Monitoring Current In A Motor During Acceleration To Verify Motor Frequency Lock
Jeffrey A. Heydt - Oklahoma City OK, US David R. Street - Oklahoma City OK, US
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
H02P 1/46 H02P 1/04
US Classification:
388847, 388911, 318706
Abstract:
Method and apparatus for accelerating a motor from an intermediate velocity to a final operational velocity. The motor is accelerated from rest to the intermediate velocity through application of fixed duration drive pulses to the spindle motor. Once the motor reaches the intermediate velocity, commutation circuitry and back electromotive force (bemf) detection circuitry use detected bemf from the motor to electronically commutate the motor to accelerate to the final operational speed. A phase lock oscillator (PLO) attempts to acquire frequency lock for the motor. A control circuit measures the current in the motor to evaluate the effectiveness of the phase lock. If the measured current is found to be above a threshold value, the motor is restarted.
Predicting Loss Of Frequency Lock Between A Motor Control Circuit And A Motor
Jeffrey Alan Heydt - Longmont CO, US David Ray Street - Allen TX, US
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
G01R 15/00
US Classification:
702 57, 702 75, 318807, 318810
Abstract:
Method arid apparatus for accelerating a multi-phase motor having a rotatable rotor are disclosed. The method incorporates use of a motor control circuit to predict a subsequent loss of frequency lock between the motor control circuit and a motor while the motor control circuit and the motor remain frequency locked, and based on the prediction, steps to avert a loss of frequency lock during acceleration. The apparatus includes at least a motor control circuit detecting frequency lock wit a motor when a motor signal falls within a timing window, and while frequency locked, predicting a subsequent loss of frequency lock based on a relative position of the motor signal within the timing window.
Closed-Loop Rotational Control Of A Brushless Dc Motor
Jeffrey A. Heydt - Longmont CO, US David R. Street - Allen TX, US Nicholas Swezey - Bartlesville OK, US Stuart Kevin Francis - Oklahoma City OK, US
Assignee:
Seagate Technology LLC - Scotts Valley CA
International Classification:
H02P 6/00
US Classification:
31840001, 318700, 318701, 31840013, 31840014
Abstract:
Method and apparatus for controlling a brushless dc motor, such as the type used in a data storage device to rotate data storage media. A sequence of drive pulses is applied to rotate the motor. The sequence is switched from first to second motor commutation states at a time determined in relation to changes in elapsed time between successive pulses in the sequence. Each drive pulse has a duration established in relation to an inductance of the motor, and is separated from adjacent pulses by an intermediate delay of predetermined value. A peak elapsed time interval between successive pulses is identified, and the next commutation state is switched in at a selected time after the peak time interval. The sequence preferably accelerates the motor from rest to an intermediate velocity, after which back electromotive force (bemf) commutation is used to accelerate the motor to a final operational velocity.
Defining A Default Configuration For Configurable Circuitry In An Integrated Circuit
David Ray Street - Allen TX, US Degang Xia - Allen TX, US
Assignee:
Texas Instruments Incorporated - Dallas TX
International Classification:
H03K 19/173 G11C 5/14 H02M 1/10
US Classification:
326 38, 326 37, 327530, 327538, 327547
Abstract:
An integrated circuit with a configurable portion, such as an input/output port, that can be placed in a default configuration prior to actual configuration of the integrated circuit. An external terminal that serves as an output during normal operation is coupled, after power-on of the integrated circuit, to a comparator that senses the voltage level at that external terminal. If the external terminal is at a particular level, a multiplexer is controlled to ignore the state of the normal configuration memory, and to place the configurable input/output port into a default protocol.
Systems And Methods For Detecting Position For A Brushless Dc Motor
A system for determining a commutation state for a brushless DC motor includes a controller configured to control current that is applied to drive each of a plurality of phases of the motor. A time delay system is configured to measure, for a given commutation state, a time delay from when a voltage associated with a driven phase of the plurality of phases crosses a predetermined threshold and a voltage associated with a floating phase of the plurality of motor phases crosses the predetermined threshold. Logic is configured to determine the commutation state for the motor based on the measured time delay.
Isbn (Books And Publications)
Organizational Change: The Political Economy Of The Ymca
Dr. Street graduated from the University of California, Davis School of Medicine in 1981. He works in Medford, OR and specializes in General Surgery and Vascular Surgery. Dr. Street is affiliated with Asante Rogue Regional Medical Center.
General Motors Feb 2011 - Feb 2012
Product Engineer
Delphi Automotive Systems Feb 2008 - Feb 2011
Advanced Design Release Engineer
Rochester Institute of Technology May 2007 - Feb 2008
Graduate Project Manager
Rochester Institute of Technology May 2006 - Feb 2008
Graduate Research Associate
Calvary Automation Mar 2005 - Dec 2005
Design Engineer (CO-OP)
Education:
Rochester Institute of Technology 2006 - 2008
MS, Manufacturing & Mechanical Systems Integration
Rochester Institute of Technology 2001 - 2006
BS, Mechanical Engineering
Skills:
Vendor Relations Concept Development Engineering Product Development Solidworks DFMEA PPAP CFD Finite Element Analysis
Interests:
Applied research and development, product development, innovation, project management, mentoring, publishing, landscaping, volleyball, electronics, automobiles, fuel cell, rapid prototyping, rapid product development
Honor & Awards:
- Honorable mention for CAST featured scholar 2006/07
Awards:
CAST Scholastic Achievement Award RIT Given to those who demonstrate leadership and exceed in their area of research. CAST Featured Scholar RIT A write-up showcasing the outstanding accomplishments of individual students who go above and beyond expectations St Lawarence Coference Best Paper Award Cornell University Certificate for excellent paper and presentation
Texas Instruments since Jan 2004
Systems Engineer
Seagate Technology 1989 - 2004
Electrical Engineer
Skills:
Semiconductors Analog Circuit Design Firmware Analog Mixed Signal SATA ASIC Debugging SoC IC Embedded Systems FPGA Hardware Architecture Power Management Electronics C Electrical Engineering CMOS Circuit Design Failure Analysis Verilog Test Engineering
JapanDirector Marketing and Business Development Asia a... Past: Director of Sales and Marketing Operations at ANSYS Japan, Director of Sales and Marketing...