Patent Document

BACKGROUND 
       [0001]    Electrical connectors are a vital, but an often overlooked part of our modern technological world. Connector design typically addresses mechanical requirements: being easy to use, durable, reliable, and safe. Connector design also typically is adapted to the electrical requirements of the application, e.g., having leads that are sized appropriately for the current that the connector will carry. 
         [0002]    Electrostatic discharge (ESD) is one concern of electrical connector design. Invisible damage may be done through ESD to some electronic components, such as capacitors, transistors, etc., that are an integral part of integrated circuit components and circuit board components in modern electronic devices. Such damage needs to be prevented even before electronic devices themselves are assembled. Technicians handling separate components, such as transistors, capacitors, circuit cards, and integrated circuits, are urged to keep electronic components in a conductive material lined static-proof bag to protect them from inadvertent ESD before they are assembled into electrical devices and products. The ESD problem is typically addressed in connector design. Even when neither electronic device being connected through a connector has a power source, there can be an ESD event for one or more of the leads of the connector. This is possible because a different charge potential may exist between the two devices when they are connected. 
         [0003]    The problem of sudden charge flow also needs to be addressed when “hot-swapping”, that is, connecting at least two components when one or more of the devices being connected with the connector has an internal or external power source providing power at the time that the connector is connected. The power source provides a means of creating a charge differential between the two components being connected whether the power source is a direct current (DC) or an alternating current (AC) source. Two leads that come in contact during a hot-swap may result in rapid discharge and potential damage to components coupled to the leads. Hot-swapping is very common today since battery powered devices are so plentiful. The installation of even a nonrechargeable battery is a hot-swap event. When the battery is rechargeable, and there is still some charge left in the battery, the connection of an unplugged charging power adapter to a connector is itself a hot-swap event. When a passively powered device is connected, for example through an Universal Serial Bus (USB) connector, plugging the passive device into the connector is a hot-swap event. Likewise, hot-swap connectors may be used for components or devices, such as laptop computers, cordless phones, cell phones, portable digital assistants, electronic notebooks, cell phones, game controllers, and remote control vehicles. 
       SUMMARY 
       [0004]    A lead of a connector is an internal or external protrusion of a connector that extends in the direction of a mating connector and that makes physical contact with a mating lead during connection of the connector. A resistive member is incorporated into the physical makeup of a connector lead by physically coupling a resistive member to a conductive member to form at least in part an improved connector lead. The conductive member has a conductive interface, such as a solder joint well, that is used to electrically join the connector through an electrical conductor, such as a lead, trace or wire to a component. Exemplary components include a capacitor, integrated circuit, memory chip, battery, computer chip, transistor, etc. A mating connector is electrically joined similarly to another component. When the two mating connector leads are connected, the improved connector at first provides a charge dissipation path through the resistive member, but subsequently provides a bypass, current-carrying, conductive path around the resistive member from one component to another. Embodiments provide an improved receptacle, plug, tab, slot, barrel plug, barrel receptacle, finger spring, finger pad, pin or pin hole connector lead. Embodiments provide a kit including an assembly consisting of an improved connector lead and a mating connector lead. Embodiments provide an electrical component, such as a battery, electronic speed controller (ESC), a computer, or a USB device incorporating an improved lead into the component, so that an improved lead is sold as part of an improved component. Embodiments provide an improved electrical device incorporating an improved lead into a product, such as a game, USB device, computer, cell phone, digital assistant, electrical gadget, toy, monitor, printer, remote control vehicle, etc. Embodiments incorporate the resistive member into the tip of a lead. Embodiments incorporate the resistive member into the middle of a lead. Embodiments incorporate an insulating jacket that is adjacent to an external conductive member, to prevent inadvertent connection or discharge, and in some embodiments, to aid retention of the resistive member. In some embodiments improved leads are joined into arrays to form an improved multi-conductor connector assembly. Embodiments provide an insulating guide. Embodiments provide a conductive ground shield. 
         [0005]    Embodiments form the resistive member from a polymer. of suitable resistance. Embodiments determine a suitable resistance value of the resistive member based on insertion time and actual or likely input capacitance, and so bound the resistance value to be used. Embodiments match the resistance value of the resistive member by determining a range within which the resistance of the resistive member is either tightly or approximately matched to a likely or actual input capacitance of an application. 
         [0006]    An assembly process provides a charge dissipation path that is used during connection of an electrical device. A first connector lead is assembled by physically coupling a first resistive member to a first conductive member, so that when the first connector lead is connected to a mating connector lead, the resistive member initially dissipates charge in a charge dissipation path through the resistive member, but the connector lead subsequently provides a conductive path that bypasses the resistive member. The conductive member of the improved lead is joined to an electrical component to provide a current carrying conductive path for an electrical device. A first mating connector is joined to a second component. The components are protected when a first improved lead is connected to the mating connector lead. In some embodiments a second connector lead is formed by joining a second conductive member to an electrical component and physically coupling a second resistive member to the second conductive member to form a second connector lead. In some embodiments an insulating jacket is installed on an exterior conductive region of an improved lead. In some embodiments an insulating guide is provided that is adjacent to the first improved lead so that the insulating guide aids in physically aligning the first connector lead to the first mating connector lead. In some embodiments a conductive shield is provided that aids in physically aligning a first improved lead and a mating lead. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention is described in detail below with reference to the attached drawing figures, wherein: 
           [0008]      FIG. 1A  presents a conventional substantially rectangular receptacle and a mating plug connector that may encounter destructive rapid discharge; 
           [0009]      FIG. 1B  presents a side elevation view of the connectors of  FIG. 1A  to expose the internal structures of the connectors; 
           [0010]      FIG. 1C  presents a conventional pin connector lead and a mating pin hole connector lead that may encounter destructive rapid discharge; 
           [0011]      FIG. 1D  presents a plan view of a conventional receptacle barrel lead and a mating plug lead that may encounter destructive rapid discharge; 
           [0012]      FIG. 1E  presents a cross-sectional view of the connector leads of  FIG. 1D , taken generally along the plane  1 E- 1 E of  FIG. 1D , in the direction of the arrows; 
           [0013]      FIG. 1F  presents an end view of a conventional receptacle barrel lead; 
           [0014]      FIG. 2A  presents a plan view of an improved receptacle barrel lead and a mating plug lead; 
           [0015]      FIG. 2B  presents a cross-sectional view of an embodiment of the connector leads of  FIG. 2A , taken generally along the plane  2 B- 2 B of  FIG. 2A , in the direction of the arrows; 
           [0016]      FIG. 2C  presents the solder-joint end view of an improved receptacle barrel lead; 
           [0017]      FIG. 2D  presents a cross-sectional view of an alternative embodiment of the connector leads of  FIG. 2A , taken generally along the plane  2 B- 2 B of  FIG. 2A , in the direction of the arrows; 
           [0018]      FIG. 3  presents a cutaway and partial cross-sectional enlarged view of the improved receptacle barrel lead of  FIG. 2A ; 
           [0019]      FIG. 4A  presents a plan view of an improved receptacle slot lead and a mating tab lead; 
           [0020]      FIG. 4B  presents a cross-sectional view of the connector leads of  FIG. 4A , taken generally along the plane  4 B- 4 B of  FIG. 4A , in the direction of the arrows; 
           [0021]      FIG. 4C  presents an end view of an improved receptacle slot connector; 
           [0022]      FIG. 5A  presents a plan view of an alternative embodiment of an improved receptacle barrel lead connector and a mating connector lead; 
           [0023]      FIG. 5B  presents a cross-sectional view of the connector leads of  FIG. 5A , taken generally along the plane  5 B- 5 B of  FIG. 5A , in the direction of the arrows; 
           [0024]      FIG. 5C  presents the solder-joint end view of an improved receptacle barrel lead; 
           [0025]      FIG. 5D  presents a cutaway and partial cross-sectional view of an embodiment of the improved barrel receptacle lead of  FIG. 5A ; 
           [0026]      FIG. 6A  presents a plan view of an improved pin connector lead and a mating pin hole connector lead; 
           [0027]      FIG. 6B  presents a cross-sectional view of the connector leads of  FIG. 6A , taken generally along the plane  6 B- 6 B of  FIG. 6A , in the direction of the arrows; 
           [0028]      FIG. 7  presents an end view of a pin hole connector lead; 
           [0029]      FIG. 8  presents a simplified equivalent circuit for choosing a resistance value for some embodiments of the resistance resistive member; 
           [0030]      FIG. 9  is a depiction of the installation of a battery in a hobby application which is performed by connecting one or more improved leads to mating leads that are coupled to an electronic speed controller; 
           [0031]      FIG. 10A  presents an improved substantially rectangular receptacle and a mating plug connector; 
           [0032]      FIG. 10B  presents a side elevation view of the connectors of  FIG. 10A  to expose the internal structures of the connectors; 
           [0033]      FIG. 10C  presents an enlarged fragmentary perspective view of the area of location  10 C in  FIG. 10B ; and 
           [0034]      FIG. 11  is a flow diagram illustrating an exemplary process for providing a charge dissipation path used during connection of an electrical device; 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    The subject matter of the present invention is described with specificity herein to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the terms “step” and/or “block” may be used herein to connote different elements of methods employed, the terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. 
         [0036]    Turning now to  FIGS. 1A-1F , there are depicted therein a number of views of different connector leads that may encounter unwanted, damaging rapid charge or discharge upon connection. Leads of such connectors typically fashion a conductive path purely from conductive materials, such as metals or alloys of copper, silver, tin, lead, etc.  FIG. 1C  shows a pin lead  161  and a mating pin hole lead  162 . When pin  161  is electrically coupled to a first electrical polarity component, such as a battery, and pin hole lead  162  is electrically coupled to a second electrical polarity component, such as a computerized device, the insertion of pin lead  161  into pin hole lead  162  results in a rapid inrush of charge into the computerized controller that may erode or damage connector surfaces and/or electrical components such as those within the computer controller. A charge flows between a first polarity component and a second polarity component when there is a charge differential between the first and second component. “Polarity” therefore refers to a difference in charge potential that results in charge flow. Under high charge capacity conditions, there may be several severe undesirable effects, as discussed more fully below when a conductive lead, such as pin lead  161 , gets close to a conductive pin hole lead  162 . 
         [0037]    Even when a connector application has relatively low charge capacity, and uses an ESD design, there still may be a negative effect from rapid inrush of charge. Consider for example, a typical substantially rectangular connector, such as Universal Serial Bus (USB) connectors, depicted in  FIG. 1A  and  FIG. 1B . Typically, plug  170  shown in  FIG. 1A  has a substantially rectangular grounding shield  132 , and an insulating guide  134  physically adjacent to finger pads  131 ,  133 ,  135 , and  137 . A mating receptacle  160  is shown in  FIG. 1A  having a substantially rectangular grounding shield  142 , an insulating guide  144 , and finger springs  141 ,  143 ,  145  and  147 . The finger pads  131 ,  133 ,  135 ,  137 , and finger springs  141 ,  143 ,  145 , and  147  in the USB leads are typically coupled to electronics components, such as a battery, power supply, line drivers, transistors, memory chips, etc., which may suffer degradation from rapid inrush of charge. Coupling, attaching, or joining leads to components is typically performed by forming a solder joint between the conductive material of a connector lead and the conductive material of a component, such as a circuit board, computer, computer board, battery, or a component lead therefrom. Other means of joining include making screw terminal connection, forming a pressure connection, forming a twist-on connection, forming a crimp connection, etc. When a receptacle  160  is mated to a plug  170 , the contacts formed are illustrated in  FIG. 1B . The ground shield  132  makes electrical contact with shield springs  151  providing an ESD charge path for a static charge differential between receptacle device and plug device. For example, a USB device may include: a computer, a laptop, an mp3 player, a docking station, a hub, a card reader, a flash drive, an external hard drive, a web cam, a speaker, an infrared adapter, an 802.11 adapter, an audio interface, a mouse, a keyboard, a trackball, a game controller, a gadget (e.g. for heating slippers, gloves, beverages, etc.), and a charger. Upon insertion, the four finger pads  131 ,  133 ,  135 , and  137  make electrical contact respectively with the four finger springs  141 ,  143 ,  145 , and  147 . As shown in  FIG. 1B , a typical finger spring, such as finger spring  141 , makes physical metal to metal contact with finger pad  131 . As shown in  FIG. 1A , the outer mating connection lead pairs  137  and  147  (typically VBUS); and  131  and  141  (typically GND), make contact forming a power supply circuit. A circuit is closed once the two pairs of leads have both made electrical contact. A charge differential necessarily exists in many such applications, such as when a USB receptacle  160  is coupled to a passive component. Therefore the charge may be rapidly discharged from a powered receptacle or jack  160  to a passive component, such as a USB flash drive, which is coupled to plug  170 . When the second pair of mating leads makes contact, the components attached to the leads may be at least incrementally degraded by a sudden rush of charge. 
         [0038]    By way of illustration, where the effect may be relatively severe, there is shown in  FIG. 1D-1F  various views of a conventional barrel connector lead  110  and a mating barrel plug lead  120  that are amenable to a hobby or robotic vehicle application, such as that shown in  FIG. 9 .  FIG. 1D  presents a plan view of a barrel receptacle lead  110  and a plan view of a barrel plug lead  120 .  FIG. 1E  presents a cross-sectional view of the connectors of  FIG. 1D  generally taken along the plane  1 E- 1 E in the direction of the arrows. This cross-sectional view shows that barrel plug lead  120  is fashioned of conductive material, and has a conductive interface  122  capable of forming a solder joint with a lead from an electrical component. Plug lead shaft  124  inserts into receptacle lead cavity  114 . The cross-sectional view of conventional lead  110  shows that lead  110  is fashioned of conductive material, and has a conductive interface  112  capable of forming a solder joint with a lead from an electrical component. Receptacle lead  110  also has receptacle cavity  114  for receiving barrel plug lead  120  to make an electrical contact between receptacle lead  110  and plug lead  120 . Conductive interfaces, such as conductive interfaces  112  and  122  also shown in  FIG. 1F , are typically available in 3.5 mm, 4 mm, 5.5 mm, 6.5 mm and 8 mm diameter channels. 
         [0039]    In  FIG. 9 , a charged battery  701  is illustrated being connected to an electronic speed controller (ESC)  702 . An ESC is a device that controls the speed of a motor using electronic components, such as Mosfets, Random Access Memory (RAM), capacitors, resistors, and an imbedded microprocessor running firmware and/or software. An ESC typically controls the timing and duration of pulses that apply power to a motor to control direction of rotation, speed of rotation, and acceleration of a rotor that is engaged with the motor. An input capacitor  750  is typically sized for the ESC  702  based on the battery  701  and current requirements. In a typical application input capacitor  750  is 1.6 millifarads for a relatively high capacity battery at 50 Volts; though voltages as high as 90 volts are also common. In this application, when connector leads  710  and  720  are of conventional type, such as lead  110 , and connector leads  730  and  740  are of conventional type such as lead  120 , rapid charge flow can have negative effects. First of all, if there is a charge differential between the battery  701  and the ESC  702 , then an ESD charge flow will result when a first lead  710  begins to connect with lead  730 . After lead  730  is seated into lead  710 , the static charge differential is equalized. Secondly, when lead  720  is subsequently about to be connected to a mating lead  740 , there may be unwanted effects of a hot-swap connection. For example one or more of the following may occur: a sound similar to a gunshot, a current that momentarily exceeds the capacity of components (such as capacitor  750 ), a current that causes the material of a component to melt, a current that causes degradation of components such as capacitor  750 , destruction of components (such as capacitor  750 ), fouling of one or more leads, melting of one or more leads, etc. 
         [0040]    Turning now to  FIGS. 2A-2D , and  FIG. 3 , there are shown several views of an improved barrel receptacle lead  210  and a mating lead  120 . A resistive member  216  is physically coupled to a conductive member  211  to form a connector lead that protrudes from the conductive member  211  in the direction of a mating connection. The physical coupling shown in  FIG. 3  is the physical insertion of resistive member  216  into a channel  238  designed to conform to the exterior region of resistive member  216  so as to provide electrical contact between  216  and  211 . Retaining groove  226  on resistive member  216  mates to retaining ring  236  to keep the resistive member in place as a plug shaft  124  ( FIG. 2B ) is inserted first into the physically coupled combination of  216  and  211 , and removed again. Retaining ring  236  has a profile  237  with two right angles to match the profile of retaining groove  226 . The profile of one or more of groove  226  or ring  236  could alternatively make use of a differently shaped profile  237 ; alternatively using an elliptical shape, triangular shape, etc. In the embodiment shown, the foot  246  of resistive member  216  mates to the seat  247  of conductive member  211  at a right angle to the exterior. Other embodiments provide a tapered angle, such as 45 degrees. In the embodiment shown in  FIG. 3 , the resistive member is retained by retaining ring  236 . Means of retention include one or more of the means shown in  FIG. 3 , mechanical retention by an exterior insulator  218  as shown in  FIG. 2B , compression connection, screw connection, conductive adhesive, plating, etc. The interior diameter of resistive member  216  after insertion is approximately equal to the interior diameter of channel  214  to provide substantially constant contact between plug shaft  124  ( FIG. 2B ) and plug receptacle  210  ( FIG. 2A ) upon insertion. In some embodiments, a resistive member, such as resistive members  216  ( FIG. 2B ),  316  ( FIG. 4B ),  416  ( FIG. 5B ),  524  ( FIG. 6B ), or  849  ( FIG. 10B ), may be formed from a low resistance Acetal Homopolymer (POM), such as Ultraform® N2320 C BK120 Q600, manufactured by BASF corporation or an equivalent. Embodiments form the resistive member from any material that exhibits desirable dissipative properties such as ceramic material, semiconductor material, polymeric material, etc. 
         [0041]      FIG. 2A  shows an improved barrel receptacle lead  210  having resistive member  216 , and a mating conventional plug connector  120 .  FIG. 2B  is a cross-sectional view of the leads in  FIG. 2A , taken along the plane  2 B- 2 B, in the direction of the arrows. As shown in  FIG. 2B , conductive member  211  has a conductive interface  212  that can be joined to an electrical component, such as component  701  ( FIG. 9 ), or  702  ( FIG. 9 ), e.g. through a solder joint, to form a current carrying path in an electrical device. Other conductive interfaces, such as metallic leads, or other types of conductive joints are contemplated in embodiments of the improved connector lead.  FIG. 2B  also shows an optional (not shown in  FIG. 2A ) exterior insulating jacket in the form of an insulating “shrink-tube” sheath  218  that encompasses an exterior region of conductive member  211  to prevent inadvertent conductor-to-conductor contact, and in the embodiment of  FIG. 2B , to aid retention of resistive member  216 .  FIG. 2C  depicts an end view of the improved barrel receptacle  210  showing the conductive interface  212 .  FIG. 2A  shows a plan-view of the improved barrel receptacle  210 .  FIG. 3  shows the sheath  218  prior to assembly in which it has not yet contracted due to the application of heat. 
         [0042]      FIG. 2D  is a cross-sectional view of an alternative embodiment of the leads in  FIG. 2A , taken along the plane  2 B- 2 B, in the direction of the arrows. As shown in  FIG. 2D , the diameter of shaft  124  indicated by distance  296  is chosen to provide constant electrical contact with the conductive member  211 , so that distance  296  is approximately equal to the diameter of channel  214 . In the embodiment depicted in  FIG. 2D , the opening of resistive member  216  at the end of the resistive member which first receives shaft  124  upon insertion has slightly larger diameter indicated by distance  297 . The diameter of resistive member  216  tapers from a diameter of distance  297  at one end of the resistive member to a diameter substantially equal to distance  296  at location  298  within the resistive member. In some embodiments distance  297  is approximately 1 mm larger than distance  296 . In some embodiments the outer diameter of barrel  210  is increased slightly, especially in the region surrounding the resistive member  216 , increasing the thickness of the shell of conductive member  211 . In some embodiments a portion of the resistive member  216  of about 1 mm length has diameter approximately equal to distance  296 . 
         [0043]    Returning to the example shown in  FIG. 9 , consider how an improved connector lead, such as lead  210 , improves performance of the connector upon connection. A lead, such as lead  210 , is coupled to a component, such as battery  701 , by soldering to it lead  703  so that lead  710  is of an improved type, such as lead  210 . A second connector lead, such as lead  120 , is soldered to lead  704 , so that lead  730  is of a conventional type such as lead  120 , thus electrically joining lead  730  to ESC  702 . The first connection illustrates how the improved connector resists and dissipates ESD. As connector lead  710  is connected to mating connector lead  730 , connector lead  710  initially provides a charge dissipation path from plug shaft  124  through resistive member  216 , through conductive member  211  from ESC  702  to battery  701 . Thus the resistive member serves to dissipate charge, and to divert the sudden rush of charge by heating the resistive member slightly rather than injecting a sudden ESD inrush of charge that may degrade electrical components within the ESC such as, capacitors, processor chips, line drivers, RAM, etc. When a plug shaft  124  ( FIG. 2B ) on lead  730  is subsequently further inserted into connector  710 , the shaft  124  ( FIG. 2B ) begins to make contact with channel  214  ( FIG. 2B ) within improved connector  710  thereby providing a bypass, current carrying conductive path from lead  703  through conductive member  211  to shaft  124  of plug  730  to lead  705  from the battery  701  to the ESC  702 . 
         [0044]    After having achieved electrical connection of lead  703  to lead  705 , an improved connector lead  720 , such as lead type  210 , further protects connectors  720  and  740  as well as the components such as capacitor  750  within a device, such as ESC  702 . Improved connector  720 , of a type such as lead  210 , is joined to lead  704  through a solder joint. A conventional plug lead  740 , of a type such as lead  120  is joined to lead  706  through a solder joint. When improved connector lead  720 , is mated to conventional connector lead  740 , connector lead  720  initially provides a charge dissipation path from battery lead  704  through conductive member  211 , through resistive member  216 , through conductive plug  120  to lead  706  from battery  701  to ESC  702 . When connector lead  740  is further inserted into connector lead  720 , connector  720  subsequently provides a bypass, current carrying, conductive path around the resistive member  216  from lead  704  through conductive member  211  through plug lead  740  to lead  706  from battery  701  to ESC  702 . When an electrical bypass path is provided, much of the charge flows through the bypass path, thus substantially bypassing the resistive member. This improvement in the second pair of connectors to be mated provides enhanced performance even for the case in which the prior electrical connection between lead  703  and lead  705  had been made using conventional leads. 
         [0045]    Continuing with the embodiment of  FIGS. 2A-2C  and  FIG. 3 , in the application of  FIG. 9 ,  FIG. 8  presents an equivalent circuit for the initial resistance upon insertion of plug  730  into receptacle  710 , after plug  740  has been fully inserted into receptacle  720 . For the purpose modeling the current flow of the equivalent circuit, the situation may be modeled as two ideal switches  710 ′ and  720 ′ of  FIG. 8  that close simultaneously with corresponding idealized connectors  730 ′ and  740 ′. Resistor  610  models the initial resistance encountered in the entire circuit from idealized battery  701 ′ to idealized capacitor  750 ′ when the resistive member  216  of the second connector begins to make contact with the second mating connector  740 . Assume that for a short time, the resistance R ohms approximates a constant resistance level provided by the resistive member. Assume further that the electrical device  702  may be modeled simply as having the value of the input capacitor  750  of C Farads. The current through the resistor  610  as a function of time may be derived as shown, for example in pp. 186-188 of Nilsson, “Electric Circuits,” Addison-Wesley, of Reading Massachusetts, © 1983, to be current I through resistor  610  for idealized battery  701 ′ of voltage V, as follows: 
         [0000]        I =( V/R ) e   −t/RC    
         [0046]    This equation may be used to advantage in sizing the resistance value R of the resistive member  216 . If it is desired to dissipate most (5 time constants) of the charge flow in a target dissipation time of 16 ms, for a capacitor of 1.6 millifarads, then a resistance value of about 2 ohms should be used. The resistance is considered to be matched to the input capacitance when it is approximately equal to 0.003 times the reciprocal of the capacitance. This gives a decay time of approximately 15 milliseconds to reach the 5 time constant limit, when the current has dropped below 1% of its maximum value. The resistance is considered approximately matched to the input capacitance when it is within a factor of 1000 above or below the matched value (either a thousand times larger, or a thousand times smaller than the matched value). The resistance value is tightly matched to the input capacitance when it is within a factor of 10 above or below the matched value (either ten times larger or ten times smaller than the matched value). In some embodiments the resistance is bounded by a factor of the capacitance, in other words, at least the dissipation time is bounded so that it is not large enough to be cumbersome to the person attaching the connector. For example, if it is desired to have the 5 time constant decay time less than 15 seconds, then the resistance is loosely bounded by the capacitance when it is chosen to be less than 3 times the reciprocal of the capacitance. The resistance is tightly bounded by the capacitance when it is chosen to be less than 0.03 times the reciprocal of the capacitance. For example, in an exemplary USB application, the maximum input capacitance is 10 microfarads, and the minimum is 1 microfarad. Therefore a resistance is tightly bounded by the maximum input capacitance when it is chosen to be less than 3,000 ohms. The resistance is tightly matched to a capacitance of 10 microfarads when it is chosen to be between 30 ohms and 3,000 ohms. 
         [0047]    Turning now to  FIGS. 4A-4C , there are depicted therein various views of an improved slot receptacle connector  310  and a mating tab connector  320 .  FIG. 4A  shows a plan view of improved slot receptacle  310  having conductive tab interface  312  at one end and resistive member  316  inserted into the opposite end.  FIG. 4A  also depicts mating tab connector  320  with tab conductors  345  and  335 .  FIG. 4B  shows a cross-sectional view of the leads in  FIG. 4A  taken along the plane  4 B- 4 B of  FIG. 4A  in the direction of the arrows. A rectangular resistive member  316  physically couples to conductive member  314 . An optional (not shown in  FIG. 3A ) insulating jacket  318  surrounds an exterior region of the connector  310 .  FIG. 4C  presents an end view of improved slot receptacle connector  310 . 
         [0048]    Turning now to  FIGS. 5A-5D , there are depicted therein alternative embodiments of an improved barrel receptacle connector  410  and mating plug  120 .  FIG. 5A  shows a plan view of the improved barrel receptacle  410  having conductive member  411  physically coupled to conductive ring  414  through three resistive members  416 . For each resistive member  416 , ribbed receiving slots in the conductive ring  414  and in the slots of conductive member  411  receive resistive member  416  during a compressive insertion of conductive ring  414  onto an assembly of conductive member  411  and the three resistive members  416 . The ribs are fashioned to grip the resistive member  416  and prevent ring  414  from decoupling from barrel receptacle  410 . The gap between conductive ring  414  and conductive member  411  is chosen to be large enough to prevent sparking around resistive members  416 .  FIG. 5C  shows the electrical interface  412  of connector lead  410 , and also shows the circular arrangement of the resistive members  416  used to connect conductive ring  414  to conductive member  411 . Conductive ring  414  is a conductive member that is coupled to one or more resistive members and protrudes in the direction intended for mating the connector to form a front portion of connector lead  410 . Embodiments replace one or two of the three resistive members  416  with insulating members, so that charge dissipates, upon connection through as little as a single resistive member  416 .  FIG. 5B  shows a cross-sectional view of the leads shown in  FIG. 5A  taken generally along the plane  5 B- 5 B of  FIG. 5A , in the direction of the arrows.  FIG. 5B  shows electrical interface  412 , and channels  423  and  421 . When mating connector  120  is connected to improved barrel connector  410 , initially the conductive plug shaft  124  makes contact with conductive member  414  providing a charge carrying path from conductive interface  122  through shaft  124 , through conductive ring  414 , through one or more resistive members  416 , to conductive member  411 , and thus to conductive interface  412 . When shaft  124  is further inserted, making contact with channel  421 , a conductive bypass path around one or more resistive members is provided from conductive interface  122  through shaft  124  to conductive member  411  and conductive interface  412 . 
         [0049]      FIG. 5D  presents an alternative configuration of improved barrel receptacle lead  410 . In  FIG. 5D , the alternative configuration of resistive member  416  still couples physically to conductive ring  414  and to conductive member  411 . In some embodiments, exterior surface  587  of conductive ring  414  has retaining ribs to mechanically couple to interior surface  586  of resistive member  416  and so to prevent ring  414  from decoupling from resistive member  416 . Similarly, in some embodiments an exterior region  597  of conductive member  411  has ribs to mechanically couple to an interior surface  596  of resistive member  416  to prevent resistive member  416  from decoupling from conductive member  411 . Other embodiments of mechanical coupling are contemplated such as one or more retaining rings, smooth surface contact adhesion, screw connection, conductive adhesive, plating, etc. 
         [0050]    Turning now to  FIG. 6A ,  FIG. 6B , and  FIG. 7 , there are depicted therein various views of an improved pin lead  520  and a mating pin hole lead  510 .  FIG. 6A  shows a plan view of mating pin hole lead  510  and of improved pin lead  520  with resistive member  524  and conductive member  511 .  FIG. 7  is an end view of pin hole lead  510 .  FIG. 6B  shows a cross-sectional view of the leads shown in  FIG. 6A  taken along the plane  6 B- 6 B of  FIG. 6A , in the direction of the arrows. The cross-section of lead  520  illustrates a conductive connecting protrusion  522  for physically coupling the conductive member  511  of the pin lead  520  to resistive member  524 . Embodiments of the pin lead  520  form threads on the protrusion  522 , and provide mating threads on the resistive member  524 . Embodiments provide ribs on protrusion  522 , and mating retention rings on resistive member  524  to couple resistive member  524  to the protrusion  522  of the pin conductive member  511 . Embodiments provide a conductive adhesive to couple conductive member  511  to resistive member  524 , applying the adhesive at least to protrusion  522 . The conductive member  511 , or a lead coupled thereto, is typically inserted into a conductive through-hole on a circuit-board and coupled additionally to one or more other electrical components, such as resistors, capacitors, integrated circuits, etc. Alternatively, a conductive cable lead is electrically coupled to conductive member  511 , and bound together with similar cable leads that are likewise coupled to additional connectors and electrical components. When an improved pin lead  520  is inserted into a pin hole lead  510 , the resistive member  524  enters channel  514  providing a charge dissipation path from conductive member  511  through resistive member  524  to conductive member  510 . As the improved pin lead is further inserted, a current-carrying bypass path is provided from conductive member  511  to pin hole lead  510  substantially bypassing resistive member  524 . In some embodiments, improved pin connector leads, such as lead  520 , or others, described herein are gathered into arrays, and used as improved pins in available connector bodies, such as D-shell connectors, substantially rectangular connectors, and compressive circular connectors that are commonly used for electronics applications. An improved array of pin connector leads, such as lead  520 , are mated with a conventional mating array of pin hole connector leads, such as lead  510 . These arrays may be provided with a circular, substantially rectangular, or D-shell conductive electrical grounding shield to provide a mechanical guide and ESD protection when mating the arrays. Such an improved array, may alternatively replace the material of conductive electrical grounding shield  842  with an insulator of the same shape, such as plastic, since an ESD solution has been incorporated into each pair of pin lead  520  and mating pin hole lead  510 . Embodiments of the guides are further discussed below. In another variation, the connector improvement is incorporated into the pin hole lead, and a conventional pin lead is used. In variations the connector leads are barrel leads, slot leads, finger spring leads, or finger pad leads. Optionally an insulating guide is used to align the leads upon insertion in addition to a conductive guide as also discussed further herein below. 
         [0051]      FIGS. 10A-10C  present views of an improved finger spring lead, such as lead  847 , for use in embodiments of an improved connector, such as receptacle  810 . A representative perspective view of plug  170  is shown in  FIG. 10A . A representative perspective view of improved receptacle  810  is shown in  FIG. 10A . Improved finger spring  847  is constructed of conductive member  841  physically coupled to resistive member  849 , as shown in area  10 C of  FIG. 10B , and also in  FIG. 10C , which is an enlarged fragmentary perspective view of area  10 C. A protrusion  881  having jagged edges is inserted into a mating slot of resistive member  849 . Embodiments of the slot in resistive member  849  include ribs to retain the resistive member after insertion. Other methods of physically coupling are also contemplated. The conductive member  841  is coupled to an electrical component, for example, by soldering into a through-hole of a circuit board the end of member  841  that is remote from resistive member  849 . The mating finger pad  131  is coupled to an electrical component similarly by soldering the end of  131  that is remote from mating connector  810  into a through-hole on a circuit board. The improved finger spring  847  is shown in  FIG. 10B . As plug  170  is inserted into receptacle  810 , an outer substantially rectangular guide  132  is inserted into an exterior substantially rectangular guide  842 , causing contact between shield  132  and guide  851 . In some embodiments guide  851  is a metallic grounding spring. In other embodiments it is simply a spring or a piece of plastic. In some embodiments guides  132  and  842  are conductive shields. In other embodiments, one or more of  132  and  842  are constructed of insulating material, as an ESD solution has been incorporated into each lead of the connection. In some embodiments, an inner insulating guide  844  encompasses an exterior side of a finger spring  847 . The insulating guides  844  and  134  serve to align lead  847  and lead  131 . The guides are formed, for example from molded plastic. When guide  842  or  132  are conductive, they are formed for example, by taking a sheet of conductive material, such as metal, stamping a pattern out of the metal, and folding the result into a substantially rectangular shell. The folded shell forming shield  842  is fastened to insulator  844  with screws. Insulator  134  is fastened to shield  132  with screws. As plug  170  is partially inserted into receptacle  810 , resistive member  849  initially contacts finger pad  831  providing a charge dissipation path from the component coupled to finger pad  831  through resistive member  849  to conductive member  841 , and thus to the component electrically coupled to member  841 . When plug  170  is further inserted into receptacle  810 , conductive member  841  makes physical contact with finger pad  831 , thus providing a bypass conductive path around resistive member  849  from the component attached to pad  831  to the component attached to member  841 . This bypass path carries current during normal operation after connection is complete. In a similar manner, at approximately the same time finger pads  133 ,  135 , and  137  make contact with finger springs  845 ,  843  and  861  respectively. In other embodiments, the finger pads, such as finger pad  131 , are replaced with finger pads that have resistive members forming the tip, and conventional mating finger springs, such as lead  141 , are used to form an improved connection. 
         [0052]    Turning now to  FIG. 11 , there is presented in  1100  an exemplary process for providing a charge dissipation path used during connection of an electrical device. This process will be described in relation to exemplary application depicted in  FIG. 9 , using an improved barrel receptacle, such as lead  210 , and a conventional plug  120 . At  1110 , a resistive member, such as resistive member  216 , is physically coupled to a conductive member, such as conductive member  211 , to form a first lead, such as lead  210 . The physical coupling method used could be physical compression, adhesion, insertion, or screw-type. At  1120 , the improved connector  210  is joined to a component, such as a battery  701  by forming a solder joint between lead  703  so that receptacle  710  is an improved receptacle lead, such as lead  210 . A mating connector, such as lead  120  is joined to a component  702 , such as an ESC by forming a solder joint between lead  705  and conductive interface  122 . If desired, a piece of insulating shrink tube  249  is cut to cover lead  703  and connector lead  710 , and heat is applied to shrink tube  249  to form an insulating jacket, such as jacket  218 . Excess shrink tube is trimmed away, especially that which might obstruct the opening of the connector lead  710 . If desired, a second resistive member, such as resistive member  216 , is coupled to a second conductive member, such as conductive member  211 , to form a second improved barrel receptacle, such as lead  210 . Alternatively a conventional receptacle  110  is used. At  1160 , second receptacle, such as lead  210 , is joined to lead  704  by forming a solder joint to conductive interface  212 , so that receptacle  720  is an improved lead, such as lead  210 . At  1170 , a mating lead, such as lead  120 , is joined through a solder joint to a lead  706  and thus joined to a device such as ESC  702  and to a component such as capacitor  750 . A piece of shrink tube is installed for lead  720  as described above. If desired, an insulating guide, such as guide  844 , is physically mounted to leads  703  and  704  to hold the leads at a fixed separating distance during connection, and an insulating guide, such as guide  134 , is physically mounted to leads  705  and  706  to hold the leads at approximately the same fixed separating distance during connection. If desired, the insulating guide  844  is surrounded by a second chassis ground shield, such as shield  842 , and insulating guide  134  is surrounded by a second chassis ground shield, such as shield  132 . At  1195 , second lead  720  is connected to lead  740 . At  1190  first lead  710  is connected to lead  730 . Embodiments of steps  1190  and  1195  occur in reverse order. Embodiments of steps  1190  and  1195  occur at approximately the same time. The description here covers variations in this process including, for example, switching components so that barrel  210  is attached to lead  705  and plug  120  is attached to lead  703 , using any improved lead plug and mating lead receptacle, or using any improved connector assembly that includes an improved lead. 
         [0053]    The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those of ordinary skill in the art to which the present invention pertains without departing from its scope. 
         [0054]    From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages which are obvious and inherent to the system and method. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

Technology Category: h