Scott L Garrett

US Patent:

55743587, Nov 12, 1996

Filed:

Dec 12, 1994

Appl. No.:

8/354340

Inventors:

Scott M. Garrett - Lawrenceville GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

G05F 1569

US Classification:

323276

Abstract:

A current limited linear regulator including a pass transistor 56 is provided with a shutdown circuit 64 comprised of a shutdown transistor 90, base resistor 92, and zener diode 98. When a excessive load is placed on the regulator and the current level limit is reached, the output voltage begins to drop and the voltage drop V2 across the pass transistor 56 increases. When the voltage drop V2 across the pass transistor 56 is equivalent to the sum of the zener voltage of the zener diode 98 and the emitter-base junction bias voltage of the shutdown transistor 90, the transistor 90 switches a current into bias resistor 62 that prevents the control circuit from regulating the output, causing the pass transistor to become highly resistive and shut off. The shutdown circuit holds this condition until the offending load is effectively removed. The zener diode is chosen according to the power rating of the pass transistor 56 and the predetermined current level limit.

US Patent:

55834159, Dec 10, 1996

Filed:

Dec 27, 1994

Appl. No.:

8/364583

Inventors:

Jose M. Fernandez - Lawrenceville GA
Vernon Meadows - Lilburn GA
Scott M. Garrett - Lawrenceville GA
Dao N. Lam - Plantation FL
James F. Kamke - Libertyville IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01M 1046

US Classification:

320 15

Abstract:

A battery system (400) for use with portable electronic products which includes protection circuitry for allowing the battery system to be safely recharged in a recharging system. The battery system (400) includes cells (401) and a plurality of controls including and overcharge protection circuit (433) for limiting the amount of current to the cells (401) by a charging network and a thermistor (415) and thermistor control (417) for controlling the state of the thermistor (415) to simulate a high temperature condition allowing the charging network to switch modes and accommodate battery system (400) which does not following the charging regimen provided by charging system.

US Patent:

60878126, Jul 11, 2000

Filed:

Jun 13, 1997

Appl. No.:

8/874811

Inventors:

George Thomas - Lawrenceville GA
Scott M. Garrett - Lawrenceville GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01M 1046

US Classification:

320141

Abstract:

A hybrid energy storage system (10) including a first energy storage device (12), such as a secondary or rechargeable battery, and a second energy storage device (14), such as an electrochemical capacitor, fuel cell, or flywheel. The second energy storage device provides intermittent energy bursts to satisfy the power requires of, for example, pulsed power communication devices. The first and second energy storage devices are coupled to a current controller to assure that pulse transients are not applied to the first energy storage device as a result of charging the second energy storage device.

US Patent:

57389195, Apr 14, 1998

Filed:

Nov 25, 1996

Appl. No.:

8/755620

Inventors:

George Thomas - Lawrenceville GA
Jose M. Fernandez - Sunrise FL
Scott M. Garrett - Lawrenceville GA
Georgina More - Duluth GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01M 1600

US Classification:

429 3

Abstract:

A hybrid energy storage system (10) including a first energy storage device (12), such as a secondary or rechargeable battery, and a second energy storage device (14), such as an electrochemical capacitor. The electrochemical capacitor provides intermittent energy bursts to satisfy the power requires of, for example, pulsed power communication devices. The first and second energy storage devices are coupled to a current controller to assure that pulse transients are not applied to the battery cell as a result of charging the capacitor.

US Patent:

55766129, Nov 19, 1996

Filed:

Jan 23, 1995

Appl. No.:

8/376613

Inventors:

Scott M. Garrett - Lawrenceville GA
Jose M. Fernandez - Lawrenceville GA
Joseph Patino - Pembroke Pines FL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01M 1044
H02J 704

US Classification:

320 54

Abstract:

A battery pack (10) includes at least one battery cell (16) and a current interrupt device (18) adapted to protect said cells from damage during charging or discharge. The battery pack (10) is further adapted to be recharged at extremely fast recharge rates via the use of a bypass switch (20) which allows current to be diverted around current interrupt device (18) during recharge. The bypass switch (20) is controlled by a control circuit (22) which provides a control signal and response to sensing a charge current.

US Patent:

55876498, Dec 24, 1996

Filed:

Sep 30, 1994

Appl. No.:

8/316678

Inventors:

Scott M. Garrett - Lawrenceville GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

G05F 1573

US Classification:

323369

Abstract:

A battery pack (10) includes a circuit (14) for assuring that a device (16) connected to the battery pack performs in a manner consistent with design requirements, while not exceeding certain thresholds for safety in volatile environments. The battery pack (10) includes a circuit (14) which matches performance requirements with the overall temperature likely to be generated by the device (16).

US Patent:

56083076, Mar 4, 1997

Filed:

Dec 29, 1994

Appl. No.:

8/368267

Inventors:

Scott M. Garrett - Lawrenceville GA
Venus D. Desai - Lawrenceville GA
Vernon Meadows - Lilburn GA
Jose M. Fernandez - Lawrenceville GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H02J 716

US Classification:

320 39

Abstract:

A battery recharge current source 12 provides a recharge current 14 to battery cells 16. Recharge current 14 is in excess of an optimum recharge current level for battery cells 16 and is divided into currents 26 and 28 by variable shunt load 24 as controlled by charge current control circuit 18. Charge current control circuit 18 is comprised of current sense circuit 20 and load control circuit 22. Current sense circuit 20 produces a current sense signal in response to current through battery cells 16. Load control circuit 22 is responsive to the current sense signal and controls variable shunt load 24 as needed to conduct excess current away from the battery cells.

US Patent:

55392997, Jul 23, 1996

Filed:

Oct 31, 1994

Appl. No.:

8/332166

Inventors:

Jose M. Fernandez - Lawrenceville GA
Scott M. Garrett - Lawrenceville GA
Vernon Meadows - Lilburn GA

Assignee:

Motorola Inc. - Schaumburg IL

International Classification:

H02J 706

US Classification:

320 39

Abstract:

A battery pack 12 for powering a device 14 sensitive to input voltage contains a protection switch 28 and a control circuit 26. When the battery pack 12 is charged by a charger 10 and the voltage of the battery pack approaches the maximum safe level of the device 14, the control circuit 26 causes the protection switch 28 to electrically switch open to protect the device 14 from excessive voltage potentially output by the charger. Where the cells 16 are lithium ion cells or a type having a maximum safe voltage, a safety switch 49 is included to interrupt charge current 52 through the cells 16. The safety switch 49 is delayed by resistor/capacitor network 51, 53 so that it switches after the protection switch 28. The safety switch 49 includes a diode 58 to allow the device 14 to remain powered while the safety switch is blocking charge current. Further, diodes 40 and 42 are required to eliminate measurement error of the control circuit 26 if the battery pack 12 is charged through the device contacts 20 and 24.