David R Street

US Patent:

6577088, Jun 10, 2003

Filed:

Sep 28, 2001

Appl. No.:

09/966673

Inventors:

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.

US Patent:

6664749, Dec 16, 2003

Filed:

Sep 28, 2001

Appl. No.:

09/966383

Inventors:

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.

US Patent:

6876510, Apr 5, 2005

Filed:

Jun 28, 2002

Appl. No.:

10/186965

Inventors:

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.

US Patent:

7062160, Jun 13, 2006

Filed:

Jun 20, 2002

Appl. No.:

10/176246

Inventors:

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.

US Patent:

7197410, Mar 27, 2007

Filed:

Aug 4, 2004

Appl. No.:

10/910993

Inventors:

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.

US Patent:

7432677, Oct 7, 2008

Filed:

Dec 16, 2004

Appl. No.:

11/014348

Inventors:

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.

US Patent:

7888965, Feb 15, 2011

Filed:

Jan 29, 2009

Appl. No.:

12/362128

Inventors:

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.

US Patent:

8237385, Aug 7, 2012

Filed:

Sep 15, 2008

Appl. No.:

12/210583

Inventors:

David Ray Street - Allen TX, US

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H02P 6/18

US Classification:

31840034, 31840006, 3184001

Abstract:

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.

Author:

David P. Street

ISBN #:

0226978508

Author:

David Street

ISBN #:

0070822832

Author:

David Street

ISBN #:

0070827052

Author:

David Street

ISBN #:

0226309622

Author:

David Street

ISBN #:

0471833258

Author:

David Street

ISBN #:

0803912277

Author:

David Street

ISBN #:

0803912285

Author:

David Street

ISBN #:

0771594518