Abstract:
Methods, apparatuses and systems for reducing or selectively terminating the power supplied to or the voltage present at the ports of electronic devices are disclosed. Methods, apparatuses and systems for reducing or terminating the power supplied to and, thus, the voltage across electrical contacts of one or more ports of a portable electronic device when the port is not in use may be effected in a variety of ways and may prevent corrosion or other moisture-induced damage to each port, and to the electronic device of which the port is a part.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     A claim for the benefit of priority is hereby made pursuant to 35 U.S.C. §119(e) to the Jan. 8, 2013 filing date of U.S. Provisional Patent Application Ser. No. 61/750,325, titled APPARATUSES, SYSTEMS, AND METHODS FOR REDUCING POWER TO PORTS OF ELECTRONIC DEVICES, The entire disclosure of which is hereby incorporated herein. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to methods and systems for reducing or selectively terminating the power supplied to ports of electronic devices. In particular, this disclosure relates to methods and systems for reducing or terminating the power supplied to and, thus, the voltage across electrical contacts of one or more ports of a portable electronic device when the port is not in use. 
     BACKGROUND OF RELATED ART 
     The durability of electronic devices is a major concern to consumers. Protective cases for cell phones, tablets, laptops, and other electronic devices are in high demand. Most protective cases provide protection from scratches and other physical damage; very few protective cases provide protection against water damage. Protective cases that provide protection against water damage do so by ensuring that the electronic device is not exposed to water, and generally encase or envelop the entire electronic device. As a result, waterproof cases tend to be somewhat bulky or large and may limit access to the electronic device. 
     Some companies, such as HzO, Inc., take a different approach to protecting electronic devices from water. HzO&#39;s approach employs the application of a thin film, or protective coating, to circuitry and/or components inside of an electronic device. This protective coating protects the electronic device from exposure to water and other types of moisture without requiring a bulky external protective case. The moisture-resistant coatings that have been developed by HzO protect electronic devices from a variety of different types of incidental or accidental exposure to moisture, including high humidity, rain, spilled drinks, the washing machine, or even if the device is immersed in water. 
     While protective coatings like those developed by HzO may protect the interior of an electronic device, the ports of the electronic device, including ports that enable charging of the battery of the electronic device and/or enable the electronic device to electrically couple to and/or communicate with other devices (e.g., computers, peripheral devices, etc.) are typically still exposed to moisture, as it is necessary to establish electrical contact with the electrically conductive features (e.g., pins, leads, other electrical contacts, etc.) of the ports for the ports to serve their intended use(s). 
     The ports of an electronic device may be used for electrical charging of batteries or other portable power supplies, data transfer, audio output/input or other functions. Typically, when an electronic device is powered on, a constant voltage is applied to its ports, regardless of whether or not a connector is externally coupled to the port, and regardless of whether or not the port is in use. If such a port is exposed to water, a short circuit between one or more electrical connectors could damage the port or the electronic device. In addition, the voltage and resulting current, combined with the water and ions, dissolved solids or other materials in the water, can degrade or damage the port by facilitating corrosion of the electrical connections. 
     SUMMARY 
     This disclosure, in one aspect, relates to approaches for providing a reduced voltage state at one or more ports of an electronic device (e.g., a consumer electronic device; a portable electronic device (e.g., a cellular telephone, such as a smart phone, a tablet computer, a portable medial player, a camera, a laptop computer, etc.), a wearable electronic device, a medical device, etc.). A reduced voltage range may be a voltage that is closer to ground state than the normal operating voltage, a voltage that is less than about 90% of the normal voltage across contacts of a port or a voltage that is less than 99% of the normal voltage across contacts of the port. In some embodiments, the reduced voltage state may include terminating power to and, thus, a voltage across contacts of one or more ports of an electronic device. A voltage control element, or switch, associated with a port may provide a reduced voltage state for the port when a connector is not coupled to the port or another electronic device is not electrically connected with, or does not communicate with the electronic device through, the port. 
     The voltage control element may be configured to detect whether or not a connector is coupled with the port. The voltage control element may also include a power controller that puts the port in a normal voltage state when a connector is coupled with the port, and a reduced voltage state when no connector is coupled with the port. 
     The voltage control element may control the voltage state of the port and its electrical contacts by connecting and disconnecting the port from its power source. In some embodiments, the voltage control element comprises a switch that is activated (i.e., the supply of power to at least one contact of the port reaches an operational level, or resumes) when a connector from another device is inserted into the port and deactivated (i.e., the supply or power to at least one contact of the port is reduced or terminated) when the connector is removed from the port. The voltage control element may comprise a physical switch situated adjacent to the port or within an opening of the port. 
     The voltage control element may communicate with a controller of the electronic device, which in turn controls the supply of power to the port and, thus, the voltage state of the port. 
     The voltage control element may include a moisture sensor configured to detect the presence of moisture adjacent to a port or within a port. Upon detecting moisture, the moisture sensor may cause the voltage control element to cause the port to be placed into a reduced voltage state, and the voltage control element may maintain the reduced voltage state until the moisture sensor indicates that the moisture levels adjacent to the port or within the port are acceptable. 
     A port adapter may be configured for insertion into a port that has no associated voltage control element to enable the port to be switched between a reduced voltage state and a normal voltage state. 
     A system according to this disclosure includes an electronic device with a port and an associated voltage control element, as well as a connector that is configured to couple with the port. Optionally, such a system may also include another electronic device associated with the connector. 
     A method for preventing electrical shorting or corrosion of the contacts of a port may include placing a port in a reduced voltage state when no connector is coupled with the port, and placing the port in a normal (e.g., operational, etc.) voltage state when a connector is coupled with the port. 
     Other aspects, as well as features and advantages of various aspects, of the disclosed subject matter will become apparent to those of ordinary skill in the art from the ensuing description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a schematic representation of an embodiment of a system comprising an electronic device that includes a voltage control element for controlling the supply of power to, and the voltage across, contacts of a port depending on whether or not a complementarily configured connector has been coupled with the port, as well as the complementary connector, which may be associated with another electronic device; 
         FIG. 2  is a schematic representation of an embodiment of a port and an associated voltage control element; 
         FIG. 3  is a schematic representation of a system including an electronic device with a conventional port and a port adapter that configured to couple with the port and includes a port extender and a voltage control element. 
         FIG. 4  is a schematic representation of an embodiment of a port, with which a voltage control element and a moisture detector are associated; 
         FIG. 5  is a block diagram of an embodiment of an architecture of an electronic device with a voltage control element; 
         FIG. 6  is a block diagram representative of an embodiment of a cellular telephone with multiple ports and multiple voltage control elements; and 
         FIG. 7  is a flow chart illustrating an embodiment of a method for placing a port in a reduced voltage state. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an embodiment of a system  100  that includes an electronic device  110  and a connector  160  of another device (not shown). The electronic device  110  depicted by  FIG. 1  includes at least one port  150  and a voltage control element  120  associated with each port  150 . The electronic device  110  may be any variety of devices. For example, the electronic device  110  may be a portable electronic device, such as a cellular telephone, a tablet computer, a portable media player, a camera, a laptop computer, any other portable electronic device or any other electronic device. 
     Each port  150  of the electronic device  110  comprises a conventional port that physically couples to (e.g., receives, etc.) a connector  160  of or associated with another device (not shown). Some non-limiting embodiments of ports  150  include a micro, mini or standard universal serial bus (USB) connector, a proprietary power and/or data connector (e.g., Apple, Inc.&#39;s 30-pin connector and LIGHTENING® connector, etc.), a subscribe identity module (SIM) card port, a tip-ring-sleeve (TRS) connector for an audio jack, a power charging port, or any other type of connector. The connector  160  may be at the end of a cable or cord, or it may be a part of any of a variety of devices, such as a dock connector. The connector  160  may comprise a stand-alone element, such as a cable or cord that connects an electronic device to a power source of another electronic device, a cable or cord or another device, such as a power source (e.g., an AC to DC adapter, etc.) or another electronic device, a stand-alone dock connector that is conjured to be coupled to a power source or another electronic device, or an intermediary device, such as a dock of another electronic device (e.g., an audio device, such as a stereo with a docking station; etc.). 
     The voltage control element  120  of the electronic device  110  is associated with the port  150  of the electronic device  110 . The voltage control element  120  is configured to determine, enable determination of or provide an indicator of whether or not a connector  160  is coupled with the port  150 . The voltage control element  120  is configured to enable power to be supplied to the port and put the port in a normal voltage state if a complementary connector  160  is properly coupled to the port  150 . Conversely, the voltage control element  120  may be configured to reduce or eliminate power supplied to the port  150 , and reduce a voltage state of the port  150 , if a connector  160  is not properly connected to the port  150 —even while the electronic device  110  is powered on and performing one or more functions. By reducing the power and/or voltage at the port  150  when no connector  160  is properly connected to the port  150 , the voltage control element  120  may reduce the likelihood of corrosion of contacts of the port or a short circuit in the event that contacts of the port  150  are exposed to moisture. 
       FIG. 1  shows the voltage control element  120  as a component of the electronic device  110 . The voltage control element  120  may be realized as hardware (e.g., as a mechanical and/or electrical switch, a proximity detector, an electrical contact, etc.) and, in some embodiments, be used with suitable programming. 
       FIG. 2  shows an embodiment of a port  150  and a voltage control element  120  associated with the port  150 . The port  150  includes electrical contacts  230 . The connector  160  ( FIG. 1 ) may include corresponding electrical contacts that correspond to and are configured to electrically connect with the electrical contacts  230  of the port  150 , facilitating the communication of data and/or power through the port  150 . Accordingly, the connector  160  may include at least a section that is sized to fit within an opening  240  of the port  150  and to couple with and establish electrical communication with the port  150 . 
     The voltage control element  120  may include a device detector  210  and a power controller  212 . 
     The device detector  210  may be configured to detect whether or not a connector  160  is properly coupled with, or connected to, the port  150  and/or whether or not another electronic device  110 ′ is connected to the electronic device  110  through the connector  160  and the port  150 . Stated again, the device detector  210  may determine that the port  150  is in one of two states: (1) coupled with a connector  160  or in communication with another electronic device  110 ′ through the connector  160  and the port  150 ; or (2) not coupled with a connector  160  or in communication with another electronic device  110 ′ through the connector  160  and the port  150 . 
     In one embodiment, the device detector  210  uses a logical determination to determine whether or not a connector  160  has been coupled with the port  150  or another electronic device  110 ′ is in communication with the electronic device  110  through the connector  160  and the port  150 . As used herein, a logical determination refers to an approach, such as that illustrated by and disclosed in reference to  FIG. 7 , that uses data communicated to and/or from the port  150  to determine whether or not the electronic device  110  communicates with another electronic device  110 ′ through the port  150 . For example, the electronic device  110  may include a controller  152  associated with the port  150  (e.g., a USB controller with a USB port, etc.). When a connector associated with another electronic device  110 ′ communicates through the port  150 , a controller or processing element of that electronic device  110 ′ may perform an enumeration process with the controller  152 . The device detector  210  may listen for communications from the other electronic device  110 ′ on the bus of the electronic device  110  to determine whether or not a connector  160  associated with the other electronic device  110 ′ has been electrically connected to the port  150  of the electronic device  110 . The term “bus” is used herein to broadly encompass a variety of approaches for communicating data, including, without limitation, peripheral component interconnect (PCI), PCI-express, InfiniBand, HyperTransport, USB, and others. The other electronic device  110 ′ may generate an interrupt or other message when the connector  160  associated therewith is electrically connected to the port  150 . The device detector  210  may listen for such a message and may determine whether or not the connector  160  associated with the other electronic device  110 ′ is electronically connected to the port  150  based on that message. 
     In another embodiment, the device detector  210  may poll the port  150  at intervals of time to determine whether or not a connector  160  associated with another electronic device  110 ′ has been coupled with and electrically connected to the port  150 . The device detector  210  may put the port  150  in a normal voltage state and then confirm that a connector  160  associated with another electronic device  110 ′ is electrically connected to the port  150  by, for example, sending or listening for one or more messages, as described previously herein. If a message is detected, the device detector  210  may confirm that communication has been established with another electronic device  110 ′ through the port  150 . If a message is not detected, the device detector  210  may determine that communication has not been established with another electronic device  110 ′ through the port  150  and the device detector  210  may return the port  150  to the reduced voltage state. 
     In other embodiments, the device detector  210  may electromagnetically determine whether or not communication has been established with another electronic device  110 ′ through the port  150 . Electromagnetic determination may employ one or more sensors to monitor the electromagnetic properties of the port  150  and/or of components attached to or otherwise associated with the port  150 . For example, the device detector  210  may monitor the resistance of one or more of the electrical contacts  230  of the port  150 . If a connector  160  is coupled with the port  150 , the connector  160  may affect the measured resistance of one or more of the electrical contacts  230 . Upon detecting this change in resistance, the device detector  210  may determine that a connector  160  has coupled with the port  150 . Alternatively, the device detector  210  may measure the voltage or the current at one or more of the electrical contacts  230  or other components connected to them to determine whether or not a connector  160  has been coupled with the port  150  or another electronic device  110 ′ communicates with the electronic device  110  through the port  150 . 
     In other embodiments, the device detector  210  may mechanically determine whether or not a connector  160  has been coupled with the port  150 . A “mechanical determination” uses a mechanical action (e.g., that caused by physically coupling a connector  160  with the port  150 , etc.) to determine whether or not a connector  160  has been properly connected to the port  150 . In the embodiment shown in  FIG. 2 , a mechanical switch  215  communicates with the device detector  210  in a manner that enables detection of a connector  160  coupled with the port  150 . For example, the mechanical switch  215  may be located within the opening  240  of the port  150  at a location that will not interfere with proper coupling of the connector  160  and the port  150 , but will enable the mechanical switch  215  to be actuated upon proper insertion of a connector  160  into the opening  240  and/or upon proper coupling of the connector  160  with the port  150 . In embodiments where a mechanical switch  215  is used, actuation of the mechanical switch  215  may cause the device detector  210  to put the port  150  in its normal voltage state. In some embodiments, the mechanical switch  215  may be depressed, and the device detector  210  may detect that a connector  160  has been coupled with the port  150 , as an electrical connection is established between the connector  160  and the port  150 . In other embodiments, the device detector  210  may determine that the connector  160  has been coupled with the port  150  before an electrical connection is established between these elements. Such an embodiment may enable the device detector  210  to restore the port  150  to its normal voltage state before the electrical connection is established between the port  150  and the connector  160 . 
     Conversely, the mechanical switch  215  may be deactivated upon (e.g., concurrently with, immediately following, etc.) at least partially uncoupling a connector  160  from the port  150 . Such action may put the port  150  in a reduced voltage state. 
     The device detector  210  is not limited to the foregoing examples in detecting whether or not the a connector has been coupled with the port  150 , or whether or not another electronic device  110 ′ communicates with the electronic device  110  through the port  150 . As another option, the device detector  210  may operate in conjunction with one or more proximity sensors or other features that enable a determination of the state of coupling, or assembly, between a connector  160  and a port  150 . The device detector  210  may, in certain embodiments, be configured to use combinations of approaches; for example, the device detector  210  may work in conjunction with a mechanical switch  215  to make an initial determination that a connector  160  has been coupled with a port  150  and, in response, temporarily put the port  150  in its normal voltage state, and then use one or more logical approaches to confirm that the connector  160  has been coupled with the port  150 . 
     If the device detector  210  determines that a connector  160  is properly connected to the port  150  (i.e., the connector  160  is configured complimentarily to the port  150  and is properly positioned relative to the port  150 ) or another electronic device  110 ′ communicates with the electronic device  110  through the port  150 , the device detector  210  may communicate the same to the power controller  212 , which may then adjust the voltage state of the port  150  accordingly. A normal voltage state refers to a voltage state for the port  150  that occurs under normal operating conditions of the electronic device  110  and the port  150 . In the normal voltage state, the electrical contacts  230  of a port  150  are at a non-zero voltage. 
     For example, a USB port  150  on a so-called “host” or “primary” electronic device  110  (e.g., a laptop computer, etc.) may have a normal voltage state of a +5 V signal at one electrical connector  230  and a 0 V (ground) signal at another electrical connector  230 , which voltages are used to provide power to peripheral devices, even if no connector  160  is properly coupled with the USB port  150 . 
     As another example, a USB port  150  of a so-called “ancillary” or “peripheral” electronic device  110  may have a 3.3 V signal on either its D+ line or its D− line to indicate the speed of the electronic device  110  and to enable the host or hub of another electronic device  110 ′ to which the electronic device  110  is connected, to detect the presence of the electronic device  110 ; when the electronic devices communicate with one another through the port  150 —even if no connector  160  is properly coupled with the USB port  150 . The normal voltage state for a port  150  may differ from one type of port to another or from one port to another, and may also differ on the basis of whether the electronic device  110  is a host device or an ancillary device. 
     If the device detector  210  determines that a connector  160  is not properly connected to the port  150 , or if another electronic device  110 ′ does not communicate with the electronic device  110  through the port  150 , the power controller  212  puts the port  150  in a reduced voltage state. A reduced voltage state for the port  150  refers to a voltage state that is closer to ground (zero volts) than the normal voltage state for the port  150 . In one embodiment, each of the electrical contacts  230  of the port  150  is set to substantially zero volts or to zero volts when the port  150  is in the reduced voltage state. 
     In another embodiment, the reduced voltage state is one where less than all of the electrical contacts  230  are set to substantially zero volts or to zero volts. For example, the power controller  212  may leave one electrical contact  230  at its normal voltage, but reduce the voltage of all of the other electrical contacts  230  to substantially zero volts or to zero volts. Such an embodiment may reduce the risk of short circuit and corrosion while enabling the port  150  to signal to the device detector  210  that a connector  160  has been properly connected to the port  150 , or that another electronic device  110 ′ is in communication with the electronic device  110  through the port  150 . The device detector  210  may, upon determining that a connector  160  has been connected to the port  150  and/or that another electronic device  110 ′ communicates with the electronic device  110  through the port  150 , cause the power controller  212  to return the port  150  to its normal voltage state. 
     In another embodiment, the reduced voltage state is one where a smaller than normal voltage (e.g., a voltage closer to ground than to the absolute value of the voltage of the normal voltage state, etc.) is applied to one or more of the electrical contacts  230 . Such a reduced voltage may comprise a small, but measurable voltage that facilitates easier detection of a connector  160  and any electronic device  110  associated therewith by the device detector  210 . 
     The power controller  212  may be situated between the port  150  and a bus  430  for communicating data and/or power to and from the port  150 . The term “bus” is used herein to broadly encompass a variety of approaches for communicating data, including, without limitation, peripheral component interconnect (PCI), PCI-express, InfiniBand, HyperTransport, USB, and others. The power controller  212  may be electrically transparent to the bus  430  and other devices in communication with the bus  430 . The power controller  212  may also be electrically transparent to other electronic devices  110 ′ that communicate with the electronic device  110  through a connector  160  and the port  150 . When the power controller  212  (which may operate under control of a program) provides the port  150  with a normal voltage state, and the electronic device  110  and another electronic device  110 ′ are electrically connected through the port  150 , the power controller  212  may act as a pass-through that simply passes along messages through the port  150 . In some embodiments, the power controller  212  may intercept messages to the port  150 . In other embodiments, the power controller  212  may emulate the port  150  on the bus  430  such that the transitions of the port  150  between the normal voltage state and a reduced voltage state are hidden from the bus  430  and the devices connected to it. 
     In some embodiments, such as that depicted by  FIG. 2 , the port  150  may receive power over the bus  430 . The power controller  212  may provide a reduced voltage state by electrically disconnecting the port  150  from its power source  400 . The power controller  212  may provide the normal voltage state by electrically connecting the port  150  to the power source  400 . The power controller  212  may act as a relay that connects the port  150  to the bus and disconnects the port  150  from the bus  430 . 
       FIG. 3  shows an embodiment of a port adapter  310  for use with an electronic device  110 . The port adapter  310  includes a port  150  and a voltage control element  120 . The port adapter  310  is configured to connect with a port  150  and facilitates communication and/or power transfer between the port  150  and a connector  160  that may be associated with another electronic device  110 ′ ( FIG. 2 ). The port  350  of the port adapter  310  is configured to couple with the connector  160  and, thus, to enable communication between an electronic device  110 ′ associated with the connector  160  and the electronic device  110  through the port  150  of the electronic device  110 . The port  350  may have the same configuration as the port  150  of the electronic device  110  or a different configuration. The voltage control element  120  of the port adapter  310  may function in the same manner or a manner similar to the function of the voltage control elements  120  described in reference to  FIGS. 1 and 2 . The voltage control element  120  may include a device detector  210  that detects whether or not a connector  160  is coupled with the port  350 , and a power controller  212  that controls the voltage state of the port  350 , like the device detector  210  and the power controller  212 , respectively, described in reference to  FIG. 2 . 
     The port adapter  310  may be configured to form a watertight seal against an exterior of the electronic device  110  when the port adapter  310  is coupled with the port  150 , such that liquid cannot enter the port  150  between the port adapter  310  and the exterior of the electronic device  110  (e.g., the port adapter  310  may include a sealing element, etc.). 
     In  FIG. 4 , an embodiment of an electronic device  110 ″ is depicted that includes a port  150 , a voltage control element  120  associated with the port  150  and a device detector  210  and a power controller  212  associated with one another and with the port  150 . In addition, the electronic device  110 ″ may include a moisture sensor  410 . The moisture sensor  410  may be configured and positioned to detect the presence of moisture at the port  150 . The moisture sensor  410  may indicate whether the port  150  is submerged in liquid, is contacted by moisture or is exposed to humidity. When the moisture sensor  410  detects moisture, the device detector  210  may cause the power controller  212  to put the port  150  in a reduced voltage state. The device detector  210  may further cause the power controller  212  to maintain the port  150  in the reduced voltage state while the moisture sensor  410  continues to sense moisture. In such an embodiment, the device detector  210  and the power controller  212  may keep the port  150  in the reduced voltage state even if a connector  160  is coupled with the port  150  or another electronic device  110 ′ communicates with the electronic device  110 ″ through the port  150 . By keeping the port  150  in the reduced voltage state when moisture is sensed by the moisture sensor  410 , the device detector  210  may reduce the possibility of corrosion or other damage to the electrical contacts  230  of the port  150 , electrical shorting between the electrical contacts  230  or damage to other components of the electrical device  110 ″. 
     Turning now to  FIG. 5 , a more specific embodiment of a system  500  for controlling the voltage states of a port  150  is illustrated. In the depicted embodiment, the system  500  includes a processor  510 , a cache  512 , a north bridge  514 , memory  516 , a south bridge  518 , a basic input/output system (BIOS)  520 , PCI  522 , a port controller  530 , and a port  150 . The system  500  may include more, fewer, or different components than those shown in  FIG. 5 ; for example, the system  500  may include a serial AT attachment (SATA) controller, a network interface card (NIC), or another component. 
     While the ensuing description relates to a specific embodiment, the components of the described system  500  may be arranged in a different manner than that described hereinafter. Without limitation, the features and functionality of the north bridge  514  and the south bridge  518 , as described below, could be flipped. 
     The processor  510  may, under control of appropriate programming, execute a series of stored instructions for the system  500 . The programming, or instructions, and other data may be stored in memory  516 . The memory  516  may be dynamic random access memory (DRAM), static random access memory (SRAM), or other suitable memory. The processor  510  may use a fast cache  512  to reduce the time necessary to access frequently used instructions and/or data stored by memory  516 . The north bridge  514  is a component for handling communications between the processor  510 , the memory  516 , and the south bridge  518 . The north bridge  514  may handle communications from other components as well, such as a video card. 
     The south bridge  518  provides input/output (I/O) functionality for the system  500  and allows the system  500  to make use of various additional components. The south bridge  518  may, for example, handle the BIOS  520 , PCI  522 , and a port controller  530 . The south bridge  518  may provide additional functionality, such as direct memory access (DMA), Ethernet connectivity, or the like. 
     The port controller  530  includes hardware and software/firmware that may enable connectivity between an external electronic device  110 ′ that communicates through the port  150  and the system  500 . The port controller  530  may, in some embodiments, be integrated into the south bridge  518 . In other embodiments, the port controller  530  is a separate element that communicates with the south bridge  518 . 
     The device detector  210  and the power controller  212  may be embodied, in whole or in part, as part of the port controller  530 . Without limitation, the power controller  212  and the device detector  210  may comprise firmware on the port controller  530 . The power controller  212  in such an embodiment may leverage the existing functionality of the port controller  530  to manage the voltage state of the port  150 . The port controller  530  may be configured to control the voltage levels at the electrical contacts  230  of the port  150  as part of its functionality for providing connectivity at the port  150 . 
     The device detector  210  of such a port controller  530  may similarly determine whether or not another electronic device  110 ′ communicates with the electronic device  110  through a connector ( FIG. 2 ) and the port  150 . For example, the port controller  530  may enable the device detector  210  to monitor changes in the voltage on the electrical contacts  230  of the port  150 . The device detector  210  may use the port controller  530  to monitor other changes in electrical properties that indicate the electrical connection of connector  160  to the port and/or communication of the electronic device  110  with another electronic device  110 ′ through the port  150 . The device detector  210  may, for example, monitor for changes in resistance, current, or electrical properties. 
     The port  150  may include a switch  215  for detecting a connector  160  coupled with the port  150 , as discussed above. In such embodiments, the system  500  may include a connector that couples the port controller  530  with the switch  215 . The port controller  530  may, for example, be a chip with one or more electrical connectors, such as pins, that are not used. A pin of the chip implementing the port controller  530  may be connected to the switch  215 . In such an embodiment, the device detector  210  implemented on the port controller  530  may be configured to recognize input on the pin as indicative of the presence and absence of a connector  160 . 
     In certain embodiments, the port controller  530  is configured to receive messages from another electronic device  110 ′ in advance of uncoupling a connector  160  from the port  150 . The other electronic device associated with the connector  160  may share one or more communications with a port controller  530  in order to prepare for separation. For example, the electronic device  110  and the other electronic device may go through an ejection process before the other electronic device is disconnected to prevent data corruption. The device detector  210  may listen for one or more messages associated with the ejection process and, once the process is complete, notify the power controller  212  that the connector  160  is no longer coupled with the port  150 . The device detector  210  may include a component implemented at the operating system (OS) level of the electronic device  110  that listens for appropriate messages indicating that the other electronic device is about to be disconnected. 
       FIG. 6  shows an embodiment of an electronic device that comprises a cellular telephone  600  with an audio port  670  and a charge port  650 . The cellular telephone  600  may include a processor  510 , a cache  512 , memory  516 , and other peripherals (such as the global positioning system GPS module  680 ), including a charge port controller  630  and an audio port controller  660 . One or more of these components may be connected by a communications channel  690  that may include one or more controllers and electrical connections that facilitate sharing power and data among components of the cellular telephone  600 . The charge port controller  630  manages the charge port  650  through which the battery of the cellular telephone  600  is charged. The charge port  650  and charge port controller  630  may provide other functions as well, such as sending and receiving audio, video, and other forms of data. The charge port  650  may be a USB port, a 30-pin port, a LIGHTNING® port, or any other suitable variety of port that may be used to charge a cellular telephone  600 . 
     The audio port  670  of the cellular telephone  600  shown in  FIG. 6  may be a TRS type audio port, as described above. The audio port controller  660  may be responsible for sending electrical signals to the audio port  670 , which electrical signals can be converted to audio by headphones or other suitable audio device connected to the audio port  670 . 
     In the depicted embodiment, the charge port controller  630  comprises a charge voltage control element  620  with a charge power controller  612  and a charge device detector  610 . The charge voltage control element  620  provides the normal voltage state and the reduced voltage state for the charge port  650  based on whether a second device  160  is connected to the charge port  650 .  FIG. 6  represents the audio port controller  660  having an audio voltage control element  662  with an audio power controller  664  and an audio device detector  666 . The audio voltage control element  662  provides the normal voltage state and a reduced voltage state for the audio port  670  based on whether or not another electronic device  110 ′ ( FIG. 2 ) is connected to the audio port  670 . 
     While  FIG. 6  shows a separate charge voltage control element  620  and audio voltage control element  662 , in certain embodiments, the charge voltage control element  620  and audio voltage control element  662  may share one or more hardware and/or logical components. A cellular phone  600  may include additional ports  150  in addition to the charge port  650  and the audio port  670 . In one embodiment, each port  150  of a cellular telephone  600  or another electronic device  110  ( FIG. 2 ) has an associated voltage control element  120  that provides a normal voltage state and a reduced voltage state. 
     Referring now to  FIG. 7 , a flow chart illustrating an embodiment of a method  700  for managing the voltage of a port  150  of an electronic device  110 , such as that represented by  FIG. 2 , is provided. The method  700  begins, at reference numeral  702 , with monitoring a port  150  of an electronic device  110 . A device detector  210  monitors a state of the port  150  to determine whether or not a connector  160  is coupled with the port  150  or another electronic device  110 ′ communicates with the electronic device  110  through the port  150 . The device detector  210  may also monitor for possible exposure of the port  150  to moisture. 
     At reference numeral  704 , the device detector  210  may determine whether or not a connector  160  associated with another electronic device  110 ′ has been coupled with the port  150  or uncoupled from the port  150 . If the device detector  210  determines that a connector  160  is not connected with the port  150 , the device detector  210  may cause the power controller  212  to put the port  150  in a reduced voltage state, at reference numeral  706 . Once the port  150  is in the reduced voltage state, the device detector  210  may continue to monitor the port  150  of the electronic device  110 , at reference numeral  702 . It may be unnecessary to proceed to a determination of whether liquid is within the port  150  if the port  150  is not connected to a second device  160  since the port  150  will already be in a reduced voltage state. 
     If the device detector  210  determines that a connector  160  and/or an associated electronic device  110 ′ have been connected with the port  150 , the power controller  212  may, at reference numeral  706 , change the voltage state of the port  150  from the normal voltage state to the reduced voltage state. 
     The method  700  may also involve, at reference numeral  708 , determining whether or not the port  150  is exposed to moisture. If the device detector  210  determines that the port  150  is exposed to moisture, the power controller  212  may, at reference numeral  706 , cause the port  150  to enter the reduced voltage state even if the port  150  is connected to the second device  160 . If the device detector  210  does not detect liquid within the port  150 , the power controller  212  may provide, at reference numeral  710 , a normal voltage state for the port  150 . As a result, the electronic device  110  may exchange power and/or data with another electronic device  110 ′ through the port  150 . 
     Although the foregoing disclosure provides many specifics, these should not be construed as limiting the scope of any of the ensuing claims. Other embodiments may be devised which do not depart from the scopes of the claims. Features from different embodiments may be employed in combination. Accordingly, all additions, deletions and modifications to the disclosed subject matter that fall within the scopes of the claims are to be embraced thereby. The scope of each claim is indicated and limited only by its plain language and the full scope of available legal equivalents to its elements.