Patents by Inventor Erika D. Mack

Erika D. Mack has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Idle current cutoff circuit
    Patent number: 5691622
    Abstract: A cutoff switch (40) separates the reference line (20) of a control circuit (18) from the B- line (24). The cutoff switch is in an electrically open state until the function of the control circuit is required, thus eliminating current flow through the control circuit when the function of the control circuit is not required. To enable the control circuit, a threshold switch (42) is provided to cause the cutoff switch to change states when the battery voltage reaches a predetermined level. To provide an override, a diode is connected between an auxiliary line (26), used a thermistor (28), for example.
    Type: Grant
    Filed: December 26, 1995
    Date of Patent: November 25, 1997
    Assignee: Motorola, Inc.
    Inventors: Erika D. Mack, Jose M. Fernandez
  • Overvoltage disconnect circuit for lithium ion batteries
    Patent number: 5637413
    Abstract: A lithium ion or similar lithium secondary battery pack (10) includes an overvoltage disconnect circuit having an overvoltage disconnect switch (14), a voltage detector (16), and a delay circuit (18). The battery pack is connectable to a recharger which was not designed to accomodate the charge regime of the lithium ion cell or cells (12), such as a nickel system recharger (20). The voltage detector samples the battery voltage and changes its output signal if the battery voltage reaches an upper voltage threshold. The output of the voltage detector will not revert back until the battery voltage drops to a lower voltage threshold, which is below the upper voltage threshold.
    Type: Grant
    Filed: October 16, 1995
    Date of Patent: June 10, 1997
    Assignee: Motorola, Inc.
    Inventors: Jose M. Fernandez, Erika D. Mack
  • Overcharge current protection circuit and battery pack using same
    Patent number: 5602460
    Abstract: A battery pack (62) comprises cells (74), and is charged by a charger (64) providing a current level. The charger (64) is a typical nickel-cadmium battery charger providing a first charge current level in excess of an optimum charge current level. The battery pack (62) further comprises a thermal sensing element (76) and an overcurrent charge protection circuit having an overcurrent switch (78), current sense circuit (80), comparator circuit (82), and temperature signal switch (84). If the current level through the cells (74) exceeds the optimum charge current level, the current sense circuit (80) provides a signal to comparator circuit (82) which actuates the temperature signal switch (84), simulating a hot battery pack. The charger (64) then switches to a second charge current level which does not exceed the optimum charge current level.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: February 11, 1997
    Assignee: Motorola, Inc.
    Inventors: Jose M. Fernandez, Vernon Meadows, Erika D. Mack, Iilonga P. Thandiwe