Abstract: A system interface having an interface for dual battery packs provides for power up sequencing of battery packs and pack switching under the control of a host processor within associated system electronics. The host processor communicates with each battery pack via a pack interface that includes a single wire mode control signal and a single wire status signal. The mode control signal allows the host processor to control the operational mode of selector switches within the respective battery pack. The single wire status signal provides status information to the host processor regarding the state of the selector switches within the respective battery pack. The mode and status signals are multi-state signals that permit at least three states to be identified via the single wire interface. Selector switches are provided only in the battery packs. No selector switches are included in the system electronics to minimize voltage drops between the selected battery pack and the system electronics.

Abstract: A single wire interface between an AC power adapter and end equipment, such as a notebook computer, conveys digital information from the adapter to the end equipment when the adapter is operative in a first operating mode and carries an analog signal employed in a closed loop to control the DC output voltage of the AC power adapter when the AC adapter is operative in a second operating mode. When the AC adapter is operative in the first operating mode, the AC adapter output voltage is clamped to a first predetermined voltage and when the AC adapter is operative in the second operating mode the output voltage is clamped to a second predetermined voltage, wherein the first predetermined voltage is less than the second predetermined voltage. Mechanisms for switching between the first and second operating modes are also provided.

Abstract: An apparatus for selectively coupling a system with a first power supply or a second power supply includes: (a) a first switch for effecting a first coupling of the system with the first power supply; (b) a second switch for effecting a second coupling of the system with the second power supply; (c) a first switch control unit coupled for controlling the first switch; (d) a second switch control unit coupled for controlling the second switch; (e) a connection director unit coupled with the first and second switch control units for providing control signals to effect the first and second coupling; at least one of the first and second coupling being effected as an initial coupling establishing a generally time-dependent increasing current between the system and one power supply and a continuing coupling establishing a substantially constant operating current between the system and the one power supply.

Abstract: The present invention comprises a combination of a new circuit topology utilizing microcontroller (202, 302) and a modified logic control circuit which enables the replacement of a Schottky diode, commonly used in series with AC adapter, by a MOS transistor switch (212, 312) to implement airline mode operation of a system, with the added benefits of more efficient power dissipation and minimization of sparking or arcing at the power input terminal.