Enhanced active port replicator having expansion and upgrade capabilities

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a port replicator and more particularly, to an active port replicator adapted to be connected to a portable personal computer to enable the portable personal computer to be connected to external I/O devices, such as a printer, full size video monitor and the like, relatively easily in a desktop application and readily disconnected for portable application, which may include one or more optional interfaces, such as a network interface for enabling the portable personal computer to be connected to a local area network (LAN) and a PCMCIA interface for enabling various options to be added, such as a fax/modem, secondary storage devices and the like.

2. Description of the Prior Art

Portable personal computers are often used in desktop applications. In such applications, it is sometimes desirable to connect the portable personal computer to external I/O devices, such as a printer, as well as a full size video monitor and a full size keyboard. For portable personal computers not equipped with an integrated trackball, it is often desired to utilize an external mouse or track ball with the portable personal computer in a desktop application.

In order to enable such portable personal computers to be used with such external I/O devices, such portable personal computers are normally provided with various ports including a parallel port, a video port, a power port and a type PS/2 port. These ports enable the portable personal computer to be connected to various external I/O devices, such as a printer, full size video monitor as well as a full size keyboard. Physically, the external I/O devices are connected to the portable personal computer with cables. When the portable personal computer is used in a desktop operation, such cables must be connected between the ports on the portable personal computer and the external I/O devices for desktop application. When the portable personal computer is used in a portable application, the cables, connected to the ports on the portable personal computer, must be disconnected and then reconnected later for desktop use, which can be cumbersome.

In co-pending patent application Ser. No. 08/104,950, filed on Aug. 10, 1993, assigned to the same assignee as the present invention, a passive port replicator is disclosed which solves such a problem. The passive port replicator is a separate unit that provides an interface between external I/O devices and a portable personal computer which facilitates use of the portable personal computer with external I/O devices as well as facilitates disconnection of such external I/O devices for portable applications. More particularly, the passive port replicator replicates external I/O ports in the portable personal computer. External I/O devices are connected to the replicated ports on the passive port replicator. The passive port replicator, in turn is connected to the external ports on the portable personal computer rather quickly and easily for desktop operation, thus obviating the need to separately connect each cable for each of the external I/O devices. For portable applications, the passive port replicator is simply disconnected from the portable personal computer rather quickly and easily, eliminating the need to disconnect each of the external I/O devices.

While the passive port replicator discussed above solves the problem associated with connecting and disconnecting external I/O devices to a portable personal computer, however, it does not provide any added functionality. In particular, in certain applications, it may be desirous to connect the portable personal computer to a local area network (LAN). Such connections are typically made by way of network interface. No such network interface is available on the passive port replicator discussed above. With an ever increasing trend of LAN's in office environments, the lack of a network interface limits the utility of a portable personal computer in a desktop application.

Additionally, newer I/O interfaces, such as a PCMCIA interface, are available which provide substantially enhanced capability for portable personal computers. Such PCMCIA interfaces also enhance the flexibility of such portable personal computers. For portable personal computers not manufactured with such a PCMCIA interface, connecting a PCMCIA interface to a portable personal computer can be difficult if not impossible, thus, undermining the flexibility of the passive port replicator.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve various problems of the prior art.

It is yet another object of the present invention to facilitate connection and disconnection of external I/O devices to a portable personal computer.

It is yet another object of the present invention to provide relatively increased capability of a portable personal computer.

It is a further object of the present invention to provide relatively increased flexibility of a portable personal computer.

It is yet a further object of the present invention to provide a port replicator for replicating ports on a portable personal computer.

It is another object of the present invention to facilitate connection of a portable personal computer to a local area network.

It is yet a further object of the present invention to provide a PCMCIA interface for a portable personal computer.

Briefly, the present invention relates to an active port replicator, adapted to be connected to a portable personal computer to enable the portable personal computer to be relatively quickly and easily connected to a plurality of external I/O devices, such as a printer, a full size video monitor and the like in a desktop application and readily disconnected from the external I/O devices for portable applications. The active port replicator replicates all of the ports on a typical portable personal computer and may provide additional ports, such as an additional type PS/2 port, for added convenience and flexibility. Once the desired external I/O devices are connected to the active port replicator, the active port replicator may quickly and easily be docked to a portable personal computer for desktop application and disconnected for portable application. In order to provide additional capability and flexibility of the portable personal computer in a desktop application, the active port replicator is user upgradeable with a network interface and a PCMCIA interface.

BRIEF DESCRIPTION OF THE DRAWING

These and other objects and advantages of the present invention will become readily apparent upon consideration of the following detailed description and attached drawing, wherein:

FIG. 1 is a perspective view of a flexible connectivity system in accordance with the present invention.

FIG. 2 is a perspective view of a portable personal computer in accordance with the present invention.

FIG. 3 is a perspective view of the portable personal computer shown in FIG. 2, illustrating an external flexible bay in accordance with the present invention.

FIGS. 4A-4D are schematic diagrams for the external flexible bay in accordance with the present invention illustrating a microcontroller and a portion of the control circuitry for the system.

FIG. 4E is a mapping diagram illustrating the positional relationship of FIGS. 4A-4D.

FIGS. 5A-5D are similar to FIGS. 4A-4D illustrating the connectors for the personal computer, printer and I/O devices installed in the external flexible bay.

FIG. 5E is a mapping diagram illustrating the positional relationship of FIGS. 5A-5D.

FIGS. 6A-6I represent flow charts for the microcontroller illustrated in FIG. 4D.

FIG. 7 is a perspective view of the external flexible bay in accordance with the present invention.

FIGS. 8 and 9 are perspective views of the external flexible bay illustrated in FIG. 7, in different states of assembly.

FIG. 10 is a perspective view of a modular battery pack for use with the external flexible bay and personal computer in accordance with the present invention.

FIGS. 11 and 12 are exploded perspective views illustrating the modular battery pack shown in FIG. 10 in different states of assembly.

FIG. 13 is a perspective view of a modular disk drive for use with the external flexible bay and personal computer in accordance with the present invention.

FIGS. 14 and 15 are exploded perspective views of the modular disk drive shown in FIG. 13 in different states of assembly.

FIGS. 16-40 are schematic diagrams for a main circuit board for an active port replicator in accordance with the present invention.

FIGS. 41-47 are schematic diagrams for a network interface board for the active port replicator in accordance with the present invention.

FIGS. 48-64 are schematic diagrams for a PCMCIA interface board in accordance with the present invention.

FIG. 65 is a perspective view of the active port replicator in accordance with the present invention illustrating the replicated ports.

FIGS. 66-71 are perspective views of the active port replicator in accordance with the present invention in various stages of assembly.

FIG. 72 is a perspective view of the active port replicator in accordance with the present invention illustrating the docking system for docking the active port replicator to a personal computer.

FIG. 73A is a partial plan view of a latch assembly for the active port replicator in accordance with the present invention shown with a personal computer shown in phantom just prior to being docked to the active port replicator and with the latch assembly in an unlatched position.

FIG. 73B is similar to FIG. 73A but with the personal computer docked to the active port replicator and with the latch assembly shown in a latched position.

FIGS. 74A and 74B represent a block diagram of the multimedia system in accordance with the present invention.

FIG. 74C is a schematic diagram of a WAV option card for the multimedia system in accordance with the present invention.

FIG. 74D is a schematic diagram of an amplifier circuit which forms part of the audio subsystem for the multimedia system in accordance with the present invention.

FIGS. 75-86 are electrical schematic diagrams of the multimedia system in accordance with the present invention.

FIG. 87 is a perspective view of the multimedia system in accordance with the present invention.

FIG. 88 is a perspective view of the multimedia system in accordance with the present invention, illustrating a portable personal computer close to being docked to the system.

FIG. 89 is a perspective view of the multimedia system showing a portable personal computer docked thereto but with a latch assembly in accordance with the present invention shown in an unlatched position.

FIG. 90 is a side elevational view of the multimedia system in accordance with the present invention showing a portable personal computer close to being docked thereto.

FIGS. 91A, 91B and 91C are exploded perspective drawings of the multimedia system in accordance with the present invention.

FIGS. 92-94 are perspective views of the bottom of the multimedia system in accordance with the present invention partially disassembled.

FIG. 95 is a perspective view of the power supply portion of the multimedia presentation system in accordance with the present invention.

FIG. 96 is a perspective view of the multimedia presentation system showing the bottom cover installed thereto.

FIG. 97 is a perspective view of a portable personal computer in accordance with the present invention with a removable LCD display.

FIG. 98 is a perspective view of a portable presentation system in accordance with the present invention for enabling an LCD display to be used remotely from said personal computer.

FIG. 99 is a bottom view of a stand assembly which forms a portion of the portable presentation system in accordance with the present invention.

FIG. 100 is a perspective view of the stand assembly illustrated in FIG. 99 shown with a bottom cover removed.

FIG. 101 is similar to FIG. 100 but shown with a connector assembly removed.

FIG. 102 is a perspective view of the connector assembly illustrated in FIG. 101.

FIG. 103 is a plan view of the stand assembly in accordance with the present invention shown with the LCD display removed therefrom.

FIG. 104 is similar to FIG. 103 but illustrating the LCD display latched to the stand assembly.

FIG. 105 is an exploded perspective view of an adapter assembly in accordance with the present invention.

FIG. 106 is a perspective view of the housing for the adapter assembly illustrated in FIG. 105 shown with a connector assembly removed.

FIGS. 107 and 108 show the electrical connections to the adapter assembly illustrated in FIG. 106.

FIG. 109 is a partial plan view of a latch assembly on the LCD display shown with the latch assembly in an unlatched position and with a mating bracket on a personal computer removed.

FIG. 110 is similar to FIG. 109 shown with the latch assembly in a latch assembly latched to a mating bracket.

FIG. 111 is an elevational view of the rear of the portable personal computer in accordance with the present invention illustrating the brackets that are adapted to engage the latch assemblies on the removable LCD display and adapter assembly.

FIGS. 112A and 112B are perspective views similar to FIGS. 110 and 109, respectively.

FIG. 113 is a partial exploded perspective view of the latch assembly on the adapter assembly in accordance with the present invention.

FIG. 114 is a partial perspective view of the latch assembly on the adapter assembly shown in an unlatched position.

FIG. 115 is similar to FIG. 114 but with the latch assembly in a latch assembly.

FIG. 116 is a simplified block diagram of the modular portable personal computer in accordance with the present invention.

FIG. 117 is a perspective view of the bottom of the modular personal computer in accordance with the present invention.

FIG. 118 is similar to FIG. 117 showing the modular devices removed.

FIG. 119 is a front elevational view of the modular personal computer in accordance with the present invention illustrating the modular bays.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a flexible modular connectivity system for a portable personal computer (PC) is shown, generally identified with the reference numeral 100. As shown, the flexible modular connectivity system 100 enables a notebook size PC 102, such as the Z-NOTEFLEX PC, as manufactured by Zenith Data Systems Corporation, in Buffalo Grove, Ill., to be rather easily and quickly connected to various input/output (I/O) devices for use in a desktop application. In particular, as will be discussed in more detail below, the flexible modular connectivity system 100 includes an active port replicator 104, which replicates various ports on the PC 102 including serial, parallel and mouse ports to facilitate use of external I/O devices with the PC 102 in a desktop application and the active port replicator 104 is user-upgradeable to provide additional interfaces for the PC 102 including a PCMCIA and a network interface. In a desktop application, the notebook size PC 102 is docked to the active port replicator 104, which, in turn, may be connected to various I/O devices, such as a desktop size monitor 106 and a printer 108. Such a configuration enables the notebook size PC 102 to be utilized with a full-size monitor 106 and a printer 108 in a desktop application, while eliminating the need for disconnecting such I/O devices when the notebook size PC 102 is used in a portable application and reconnecting the devices 106 and 108 for a desk-type application.

As shown, the desktop size monitor 106 is directly connected to a video port 110, available on the active port replicator 104, with a suitable cable 112. The printer 108, in turn, may either be connected to a parallel port 114 on the active port replicator 104 or may be connected by way of an external flexible bay 116. When the printer 108 is connected by way of the external flexible bay 116, a cable 117 is used to connect the parallel port 114 on the active port replicator 104 to the external flexible bay 116. The printer 108, in turn, is connected to the external flexible bay 116 by way of another cable 118. In this application, the external flexible bay 116 acts as a pass-through device for the parallel port 114 on the active port replicator 104.

In addition to the parallel port 114 and video ports 110, the port replicator 104 may also be configured with a serial port 119 and two type PS/2 ports 120 and 121. The type PS/2 ports 120 and 121 enable an external mouse 122 to be connected to the port replicator 104 by way of a suitable cable 124 and an external keyboard (not shown) for desktop application.

As will be discussed in more detail below, the external flexible bay 116 may be used for either a modular floppy disk drive 125 (FIG. 13) or for charging a modular battery pack 127 (FIG. 10). Moreover, in order to provide optimum flexibility of the system 100, various connection configurations are possible for battery charging. For example, as shown in FIG. 1, a suitably sized AC to DC converter 126 is connected to a source of AC electrical power 128 by way of an appropriate cable 130. In this application, the AC to DC converter 126 is connected both to the active port replicator 104 and the external flexible bay 116 in order to charge the battery pack 127 (FIG. 10), disposed within the external flexible bay 116, as well as a battery pack 127 (FIG. 2) within portable PC 102. As will be discussed in more detail below, the battery pack 127 within the external flexible bay 116 is given charging priority. In particular, the AC to DC converter 126 is connected to a power port 132 on the port replicator 104 by way of a suitable cable 134 (FIG. 1). The power from the AC to DC converter 126 is passed through to the external flexible bay 116 by connecting a suitable cable 136 to an additional power port 138 on the rear of the active port replicator 104.

In an alternate configuration (not shown), the AC to DC converter 126 is connected directly to the external flexible bay 116, which, in turn, is connected to a power port (not shown) on the rear of the PC 102. Alternately, the AC to DC converter 126 can be connected directly with the PC 102 with or without the active port replicator 104 to charge the battery pack within the PC 102. Depending on the configuration used, the capacity of the AC to DC converter 126 must be sized accordingly.

The external flexible bay 116 provides for various configurations for optimum flexibility. More particularly, the external flexible bay 116 may be used as an external floppy disk drive 125 or for charging a spare battery pack 127. For example, a modular battery pack 127 (FIG. 10) may be charged by way of the external flexible bay 116. In this application the battery pack 127 is inserted within the external flexible bay 116, connected as discussed above. In an alternate configuration, the external flexible bay 116 may be used with the modular floppy disk drive 125 (FIG. 13). In this application a floppy disk drive 125, as will be discussed in more detail below, is removed from the notebook size PC 102 as shown in FIG. 2 in order to receive a spare battery pack 127 to provide additional battery capacity for the PC 102 in a portable application.

When the system 100 is configured as illustrated in FIG. 1, the external flexible bay 116 will have two modes of operation under the control of a mode select switch 137 (FIGS. 1 and 7) disposed on the external flexible bay 116. In a floppy drive mode, the external flexible bay 116 acts as an external floppy drive. In a printer mode the external flexible bay 116 merely acts as a pass-through parallel port for the printer 108. In this mode the external floppy drive 125 is disabled as will be discussed below.

The PC 102, adapted to be utilized with the flexible system 100, is illustrated in FIGS. 2 and 3. In particular, the notebook size PC 102 is configured with a flexible bay 141 and a battery pack bay 142. The battery pack bay 142 is configured to receive the modular battery pack 127, as shown. In order to provide additional battery capacity for the PC 100 in a portable application, the flexible bay 141 is adapted to receive either the modular battery pack 127 or the modular floppy disk drive 125. In particular, in order to provide additional battery capacity in a portable application, the modular floppy disk drive 125 may be removed from the flexible bay 141 and may be inserted into the external flexible bay 116. An additional modular battery pack 127 may then be disposed within the battery pack bay 141 to double the battery capacity of the PC 100 for a portable application. As will be discussed in more detail below, the modular floppy drive 125, as well as the modular battery pack 127, are dimensioned to be received within either the flexible bay 141 within the notebook size portable PC 102 or within the external flexible bay 116 to provide optimum flexibility.

External Flexible Bay

The schematic diagrams for the external flexible bay 116 are illustrated in FIGS. 4A-4E and 5A-5E. The software for the external flexible bay 116 is illustrated in FIGS. 6A-6I. A copy of the source code for the external flexible bay 116 is attached as Appendix A. As will be discussed in more detail below, the external flexible bay 116 is adapted to communicate with the modular battery pack 127 by way of a serial communications link. The modular battery pack 127, as well as the software control of the modular battery pack 127, is disclosed in detail below.

Since the AC to DC converter 126 provides the requisite power for the external flexible bay 116, the AC to DC converter 126 is connected to the external flexible bay 116 either directly or by way of the port replicator 104 as illustrated in FIG. 1. As discussed above, the AC to DC converter 126 may be connected to a power port 132, for example, an 8-pin connector 150 on the external flexible bay 116, or alternatively, as shown in FIG. 1 or as discussed above. When the AC to DC converter 126 is connected either directly to the external flexible bay 116 or by way of the port replicator 104 and the cable 136 (FIG. 1), the positive DC voltage from the AC to DC converter 126 is available on the DCIN and CHRGIN pins on the connector 150 (FIG. 4A). The DC voltage from the AC to DC converter 126 is used to develop a power supply VCC3, for example, 3.3 Vdc, for a microcontroller 154 (FIG. 4D). In particular, the DCIN pins on the power port connector 150 are connected to a switching power supply, indicated within the dashed box 156 (FIGS. 4A and 4B). The switching power supply 156 may include resistors 158, 160 and 162; capacitors 164, 166, 168, 170, 172, 174, 176, 178; ferrite bead inductors 180, 182; a wire-wound inductor 184; a Schottky diode 186; a field-effect transistor (FET) 188; and a switching regulator IC 190, such as a Model No. 11475, as manufactured by Linear Technology, which includes a power drive output pin Pdrv, which drives the gate of the FET 188.

The output of the switching regulator 156 is serially connected to a linear voltage regulator 192, for example, a Model No. LD2951, by Micrel, which provides a 3.3 volt output, identified as VCC3, for use as a power supply voltage for the microcontroller 154. In order to stabilize the input and output voltages, capacitors 194 and 196 are connected between the input and output pins, IN and OUT, respectively, of the linear voltage regulator 192. Two voltage divider resistors 198 and 200 are selected to provide an output voltage at the output terminal OUT to be 3.3 volts for use by the microcontroller 154.

The external flexible bay 116 is a flexible bay and, as mentioned above, is adapted to be utilized for a modular floppy drive 125 or to charge a modular battery pack 127. When the external flexible bay 116 is used to charge the modular battery pack 127, the circuitry determines the status of the modular battery pack 127 installed in the external flexible bay 116. The modular battery pack 127 when installed in the external flexible bay 116 is given priority over any modular battery pack 127 in the notebook size PC 102. As discussed in detail in U.S. Pat. No. 5,629,604, issued May 13, 1997, hereby incorporated by reference, the charging requirements of the modular battery pack 127 are provided by way of a charge control signal. In particular, the charge control signal controls the amount of charging current to be provided by the AC to DC converter 126 to the modular battery pack 127 as a function of the state of charge of the modular battery pack 127. Since the system 100 is capable of being utilized with a modular battery pack 127 installed within the external flexible bay 116, as well as a modular battery pack 127 installed within the portable PC 102, two charge control signals CHRGCNTRL and CHRGCNTRLI (FIG. 4A) are defined. The charge control signal CHRGCNTRL is used in conjunction with the modular battery pack 127 installed in the external flexible bay 116, while the charge control signal CHRGCNTRLI is used for the modular battery pack 127 installed within the portable PC 102.

The charge control signal CHRGCNTRL for the modular battery pack 127 installed in the external flexible bay 116 is available at a connector 210 (FIG. 5D), used to connect the battery pack 127 to the external flexible bay 116. The charge control signal CHRGCNTRLI is available at a connector 212 (FIG. 4A), used to connect the portable PC 102 to the system 100. A pair of multiplexers (MUXES) 214 and 216 (FIG. 4C) are used to control which of the two charge control signals CHRGCNTRL and CHRGCNTRLI are connected to the system 100. Depending on which modular battery pack 127 has priority, the charge control signals CHRGCNTRL and CHRGCNTRLI are amplified by an amplifier 218 whose output forms a charge control output signal CHRGCNTRLO to battery charger 126, available at the connector 150 (FIG. 4A). As discussed in detail in the above-mentioned U.S. Patent, the charge control output signal CHRGCNTRLO controls the amount of charging current supplied by the AC to DC converter 126 (i.e., the current supplied by the AC to DC converter 126 to the CHRGIN terminals on the connector 150 or 212).

The charge control signal amplifier 218 (FIG. 4C) may be configured as an operational amplifier with its inverting input tied to its output, which, in turn, is connected to the charge control output signal CHRGCNTRLO. The charge control signals CHRGCNTRL and CHRGCNTRLI from the modular battery packs 127 from the external flexible bay 116 or the PC 102, respectively, are applied to the noninverting input of the amplifier 218. In particular, the charge control signal CHRGCNTRL is dropped across a resistor 220 and applied to the non-inverting input of the operational amplifier 218 by way of a pair of voltage divider resistors 222 and 224 and the MUX 214. The charge control signal CHRGCNTRLI from the modular battery pack 127 within the PC 102 is applied to the noninverting input of the amplifier 218 by way of the MUX 216 and the voltage dividing resistors 222 and 224. Thus, depending on the states of the MUXES 214 and 216, either the charge control signal CHRGCNTRL or CHRGCNTRLI will be amplified by the amplifier 218 to provide the control signal CHRGCNTRLO to the battery charger 126.

The system 100 is further adapted to sense when the PC 102 is on. In particular, the DC current supplied by the AC to DC converter 126 is dropped across a sensing resistor 226 (FIG. 4A), connected to the DCIN pin on the connector 150 by way of a fuse 228. The voltage drop across the resistor 226 is amplified by an amplifier 230 (FIG. 4C). In particular, the junction between the resistor 226 and the fuse 228 is applied to an inverting input of the amplifier 230 by way of a resistor 232. The other side of the resistor 226 is applied to a noninverting input of the amplifier 230 by way of a resistor 234. The noninverting input of the amplifier 230 is referenced to a predetermined reference voltage by way of the voltage divider resistors 235 and 237 being connected to the output of the VCC3 of the linear regulator 192 (FIG. 4B). The inverting input is also connected to the output by way of a resistor 239 and connected to ground by way of a resistor 243. The resistors 232, 234, 237 and 243 determine the gain of the amplifier 230 while the resistors 235 and 243 add a DC offset.

Since the amplifiers 218 and 230 are, in essence, being used as current amplifiers, the negative power supply input -V is grounded. The positive power supply voltage +V is derived from the input voltage from the AC to DC converter 126, available at the DCIN terminal at the connector 150 by way of the resistor 226 and the fuse 228. A capacitor 241 stabilizes the voltage to the input power supply +V of the amplifiers 218 and 230.

As mentioned above, the current-sensing resistor 226 is used to determine when the PC 102 is on to ensure that the maximum composite output current (i.e. DCIN+battery charger) of the battery charger 126 is not exceeded. In particular, the DC current supplied from the AC to DC converter 126 is dropped across the resistor 226, a resistor 235 and a resistor 237 to define a voltage, proportional to the amount of DC current supplied by the AC to DC converter 126. This voltage is read by the microcontroller 154 (FIG. 4D) at port PB4 by way of a voltage divider which includes the resistors 242 and 244 (FIG. 4C). In order to ensure that the signal does not change during the A/D sample period, a low-pass filter (FIG. 4C) is connected between port PB4 and ground. The low-pass filter includes a single capacitor 248 incorporated into the voltage divider network. The microcontroller 154 may be, for example, an SGS Thompson type ST6225 microcontroller, which includes an on-board analog-to-digital converter. As such, the analog voltage signal representing the DC current being supplied by the AC to DC converter 126 may be applied directly to the microcontroller 154.

As will be discussed in more detail below, the modular battery pack 127 installed in the external flexible bay 116 is given priority over the modular battery pack 127 within the notebook size PC 102. The charge control signal CHRGCNTRL is used to read the battery charge level and set an external port PB3. Thus, when the charge level of the modular battery pack 127 within the external flexible bay 116 is low, the output signal on the external port PB3 (FIG. 4C) on the microcontroller 154 will be low, which, as will be discussed in more detail below, will connect the output power from the AC to DC converter 126 to the modular battery pack 127 installed in the external flexible bay 116. More particularly, the DC power from the AC to DC converter 126 is available at the CHARGIN pin on the input port connector 150 (FIG. 4A). This signal CHARGIN is connected to a switch 245, which may be implemented as a FET. In particular, the source terminals of the FET 245 are connected to the CHARGIN pin on the power port connector 150, while the drain terminals of the FET 245 are connected to a positive DC terminal BATT+ on the connector 210 (FIG. 5D) to connect the AC to DC converter 126 to the modular battery pack 127 within the active port replicator 104. The FET 245 is under the control of another switch 247, which may be implemented as a bipolar junction transistor (BJT).