Abstract:
A connector for a re-manufactured automotive alternator includes a first terminal blade and a second terminal blade within a connector housing. The connector housing receives a mating housing. The first terminal blade and the second terminal blade are flexibly coupled to a common base by at least one respective bend. The first and second terminal blades are adapted to mate to mating connectors within the mating housing. The bend that couples the two blades to the common base flexes to allow the first and second terminal blades to move to adapt to varying positions of the mating connectors within the mating housing.

Description:
RELATED APPLICATIONS  
       [0001]    This application is continuation of U.S. patent application Ser. No. 10/008,303, filed on Nov. 6, 2001, which is a divisional application of U.S. patent application Ser. No. 09/412,931, filed on Oct. 5, 1999, which claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 60/103,682, filed on Oct. 8, 1998, U.S. Provisional Patent Application No. 60/103,412, filed on Oct. 7, 1998, U.S. Provisional Patent Application No. 60/129,738, filed on Apr. 16, 1999, and U.S. Provisional Patent Application No. 60/139,998, filed on Jun. 18, 1999. 
     
    
     
         [0002]    BACKGROUND OF THE INVENTION  
           [0003]    1. Field of the Invention  
           [0004]    The present invention relates to the field of automotive rectifier assemblies. Particularly, the present invention relates to a method and apparatus for preventing rectifier assemblies from overheating.  
           [0005]    2. Description of the Related Art  
           [0006]    Advances in technology have allowed for a reduction in the size of automotive alternators (herein “alternators”). Although alternators have become smaller, the electrical energy output requirements have increased. Generally, recharging an automobile&#39;s battery requires a current between 40 and 50 amperes. Combined with the energy requirements of the air conditioning system, the computer module, the car radio, the fans, and the lighting systems, the overall current consumption can exceed 150 amperes.  
           [0007]    The high current alternator is generally not able to dissipate heat out of the rectifier module fast enough to prevent semiconductor failure. The problem is particularly severe during the summer months, when the ambient temperature is quite high, thus reducing the rate of heat transfer between the rectifier module and the surrounding environment.  
           [0008]    Polyphase alternating current can be converted to direct current suitable for use in an automotive electrical system by conducting current through semiconductor diodes in a rectifier circuit. The semiconductors may be affixed directly onto a heat sink, as is illustrated by U.S. Pat. No. 5,005,069, or press-fit into pre-punched holes in the heat sinks, as is illustrated by U.S. Pat. No. 5,043,614. In other methods, such as that illustrated in U.S. Pat. No. 4,799,309, the semiconductors are affixed onto integrated heat sinks. The heat control methods identified above are usually difficult to implement because the semiconductors are extremely sensitive to heat, stress, and mechanical force applied to the semiconductors during the manufacturing and installation. The stress can cause premature semiconductor failure during vehicle operation.  
           [0009]    The likelihood of failure is especially great when the semiconductors of the rectifier assembly are affixed onto a single, integrated, aluminum heat sink. The semiconductors are usually encapsulated with heat conductive epoxy, which prevents the semiconductors from expanding or from dissipating heat efficiently. The semiconductor overheating and failure conditions has been historically demonstrated by the FORD IAR alternator catastrophic failure scenario. Therefore, there is a need for a method of ensuring that the rectifier assembly does not overheat when semiconductors fail while not overstressing the semiconductors during assembly.  
           [0010]    Automotive power requirements utilizing a rectifier can exceed 70 amperes. With the present day high under-hood temperatures, along with the heat generated by the alternator and the rectifier, this high current cannot safely pass through the rectifier male terminal blades and into the female connector terminals when the terminals are not properly mated.  
           [0011]    Most rectifier assemblies use three male terminal blades molded into a connector housing. The B+ blades that supply the battery power are formed out of tin plated brass or steel and are bent into a “U” configuration (usually a square bend molded into a housing, and having no flexibility) to carry the high current. The third independent blade is used to transfer low amperage stator alternating current to the electric choke circuit.  
           [0012]    In the prior art, when the original alternator, rectifier and connector are manufactured, assembled and installed by the manufacturer, the system operates quite well for several years. However, after operating for several years, under the stress of high current and high under-hood temperatures, the materials take on a preset form, or memory.  
           [0013]    Replacing a failed alternator presents a major problem for the re-manufacturer and the installer because the installer must force and pry off the tightly fit female mating connector. After installing a remanufactured alternator, the mating connector is mechanically distorted, thermally aged, or has a preset memory. Thus, the connector terminal blades most likely will not align with the female receptacle terminals, creating a high resistance loose connection, causing arcing, over-heating, and introducing a fire hazard.  
           [0014]    In an attempt to solve the problem, many large volume alternator re-manufacturers enclose a new connector plug with every alternator sold. This practice is extremely expensive, and cannot guarantee the rectifier contact blades will be properly aligned to provide a low resistance tightly fit connection after the installer forces the new connector into the re-manufactured alternator rectifier.  
           [0015]    Other alternator re-manufacturers recommend that their customers perform a 6 pound pull test on the connector plug prior to plugging it into the newly installed alternator. A 6 pound weight is attached to a single male terminal blade. The blade is then plugged into each of the three female receptacles. If the weight causes the male blade to pull out of any one of the three female receptacles, the existing automobile&#39;s connector must be cut out and a new connector is spliced into the circuit. The installer must then force the new female connector from side to side, while pushing it downward into the male housing, allowing the male blades to enter into the female receptacles. This action causes the male blades to bend.  
           [0016]    Because the male terminal blades cannot self-align, they lose their required contact surface area, and create a high resistance connection. This connection becomes a hot spot within the connector housing because of the high operating current conducted through it. The extra heat generated within the re-manufactured alternator will not allow it to dissipate out of the rectifier. As heat continues to build up within the rectifier it either fails or becomes a fire hazard.  
         SUMMARY OF THE INVENTION  
         [0017]    In accordance with the present invention, a rectifier assembly employs semiconductor circuits that automatically open whenever the semiconductors fail and dissipate a predetermined level of heat.  
           [0018]    In one embodiment, the present invention utilizes spring-loaded terminals to connect the semiconductor circuits such that, when a failure occurs, the high temperature causes a preselected soldered joint to melt. Once melted, a compressed spring, under the joint, holds the terminals away from one another to open the failed circuit and stop the current flow.  
           [0019]    In one embodiment, the rectifier assembly includes six spring-loaded diodes affixed onto two copper heat sinks. The heat sinks provide cooler and more efficient operation as described in U.S. Pat. No. 5,659,212, incorporated herein by reference.  
           [0020]    The present invention is concerned with the high power and under-hood temperatures required by modern day automotive electronics and the catastrophic fire and melt down hazards caused by overheated semiconductors. The method of the present invention avoids overstressing the semiconductors by preventing the circuits from operating in a range of operation that is beyond the semiconductor&#39;s handling specifications. The thermal protection of the present invention virtually eliminates the automobile&#39;s catastrophic fire hazard, the dead battery nuisance conditions, and other conditions that are associated with semiconductor failures.  
           [0021]    The present invention also offers a method for assembling rectifiers without overstressing the diodes in the process of securing the diodes to the rectifier assembly. The method includes providing a protective cup that is used to hold the semiconductor diode and absorb stress that may otherwise be absorbed by the semiconductor body.  
           [0022]    The rectifier of the present invention employs a terminal connector that utilizes dimpled or detented (e.g., corrugated), spring-loaded, self-aligning male terminal blades to compensate for tolerances between all manufactured connectors. The terminal blades also compensate for the existing automobile connector which may be out of tolerance, because of thermal aging, mechanical abuse, or preset memory. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    [0023]FIG. 1 illustrates a rectifier bridge alternator circuit;  
         [0024]    [0024]FIG. 2 illustrates a rectifier bridge alternator circuit with the thermal safety disconnects of the present invention;  
         [0025]    [0025]FIG. 3A illustrates a Ford 3G rectifier bridge;  
         [0026]    [0026]FIG. 3B illustrates a Ford 3G rectifier bridge with thermal safety disconnects;  
         [0027]    [0027]FIG. 4A illustrates a rectifier assembly with safety washers;  
         [0028]    [0028]FIG. 4B illustrates a side view of a diode pair assembly with a thermal safety washer in place;  
         [0029]    [0029]FIG. 5A illustrates a side view detail of the rectifier assembly of FIG. 4A;  
         [0030]    [0030]FIG. 5B illustrates a rectifier assembly and the stator field coil circuits;  
         [0031]    [0031]FIG. 5C illustrates the capacitor assembly of the rectifier circuit;  
         [0032]    [0032]FIG. 6 illustrates details of a button-type semiconductor with a spring pull-off, contact safety release;  
         [0033]    [0033]FIG. 7A illustrates a cross section of a pan type semiconductor assembly with safety washers;  
         [0034]    [0034]FIG. 7B illustrates a cross section of the pan type semiconductor assembly of FIG. 7A after a thermal failure condition;  
         [0035]    [0035]FIG. 7C illustrates an alternative embodiment of a diode pair assembly;  
         [0036]    [0036]FIG. 8A illustrates a semiconductor prior to being pressed into a heat sink;  
         [0037]    [0037]FIG. 8B illustrates the semiconductor of FIG. 8A after being pressed into the heat sink;  
         [0038]    [0038]FIG. 8C illustrates the semiconductor assembly of FIG. 8B after a thermal failure condition;  
         [0039]    [0039]FIG. 9 illustrates a rectifier press-fit semiconductor diode assembly;  
         [0040]    [0040]FIG. 10 illustrates the diode assembly of FIG. 9 after a thermal failure condition;  
         [0041]    [0041]FIG. 11 illustrates a spring loaded semiconductor diode assembly;  
         [0042]    [0042]FIG. 12 illustrates the diode assembly of FIG. 11 after a thermal failure condition;  
         [0043]    [0043]FIG. 13A illustrates an exploded view of an alternative embodiment of a diode pair safety connector assembly;  
         [0044]    [0044]FIG. 13B is a side view illustration of the completed assembly of FIG. 13A;  
         [0045]    [0045]FIG. 14 illustrates an expanded view of an alternate embodiment of a diode pair safety connector assembly;  
         [0046]    [0046]FIG. 15 illustrates a connection of diode pairs by a safety bracket;  
         [0047]    [0047]FIG. 16 illustrates the positive heat sink of FIGS. 4A and 5A;  
         [0048]    [0048]FIG. 17 illustrates the negative heat sink of FIGS. 4A and 5A;  
         [0049]    [0049]FIG. 18 illustrates an alignment rail that ensures proper mating with the female connector from the automobile wiring harness; and  
         [0050]    [0050]FIG. 19 illustrates the insulating gasket of FIGS. 4A and 5A. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0051]    The structure and operation of the semiconductor safety assembly of the present invention will be discussed with reference to embodiments of automotive rectifier assemblies. First, a problem associated with semiconductor diodes of automotive rectifier assemblies will be discussed. Second, several modification to existing rectifier assemblies will be illustrated. Next, the structure of semiconductor diode safety disconnects will be discussed with reference to illustrations of rectifier assemblies and diode pair assemblies.  
         [0052]    Although the safety assemblies of the present invention are disclosed with reference to an automotive rectifier assembly, the disclosure is equally applicable to other circuits that employ semiconductor components that are susceptible to overheating as a result of a failure condition.  
         [0053]    One problem solved by the safety assemblies of the present invention relates to alternator rectifier circuit semiconductor diode failures. Once an alternator is installed in a vehicle, all semiconductor diodes are electrically connected to the battery, completing a number of potential short circuit paths to the ground. The charging system&#39;s wiring harness usually incorporates a 12 AWG fuse link safety circuit, for fire and meltdown protection. The fuse, however, only provides an illusion of safety, as is discussed below.  
         [0054]    Heat and voltage transients degenerate semiconductor switches and cause undesired reverse current leakage through the semiconductor junction. The leakage can lead to excessive junction heating. Once overheated, the semiconductor switch may be damaged beyond recovery. The semiconductor switch may also lose its blocking characteristics and allow current to flow in both directions. The excessive heat can then cascade into and damage other semiconductor switches of the same circuit.  
         [0055]    Generally, there are no cut out relays or switches that open the semiconductor circuits of the rectifier system when a vehicle is shut down. Thus, the circuits usually remain electrically “HOT” when the vehicle is shut down. Further, the alternator&#39;s cooling system is also shut down when a vehicle is not operating, thus leaving the circuits thermally vulnerable. Latent heat remains in the thick rectifier housing and conducts back into the semiconductors. Thus, the alternator of the unattended shut-down vehicle is slowly heating up, as heat cascades from one semiconductor to another, causing semiconductor failures, and generating enough heat so as to potentially ignite an under-hood fire.  
         [0056]    When the semiconductors fail, the current level is generally not high enough to melt the 12 AWG fuse. The semiconductors usually fail with a combined resistance of approximately 0.3 ohm. Thus, a 40 ampere current flows through the failed circuit. The level of current translates to 480 watts generated within the rectifier case. The 480-watt power output is 13 times greater than an average 37-watt soldering iron used in the electronics industry.  
         [0057]    The failed semiconductors become high wattage heaters that are controlled by the hot silicon&#39;s resistance, overheating the path through the copper components, melting the plastic affixing the terminals, melting the epoxy fillers, and igniting any grease or oil on the wiring harness insulation. Furthermore, the leakage path does not conduct enough current to melt the 12 AWG fuse link. Therefore, there is only an appearance of safety when employing the fuse link. Once started, the meltdown continues until the battery is discharged or manually disconnected. Further, rectifiers that fail without a catastrophic failure are still a nuisance to the general public because of the required service calls, the towing, and the repair costs.  
         [0058]    [0058]FIG. 1 illustrates a typical rectifier bridge configuration of an alternator circuit. The rectifier bridge circuit  100  is connected to the stator windings  101 ,  102 ,  103 . The rectifier bridge circuit  100  is also connected to the negative terminal  112  of the battery  114 . The rectifier bridge circuit  100  includes six diodes  104 - 109 . A first set of diodes  104 - 106  is thermally and electrically coupled to a first heat-sink (FIG. 4A). A second set of diodes  107 - 109  is thermally and electrically coupled to a second heat-sink. The anodes of the first set of diodes  104 - 106  are connected to the cathodes of the second set of diodes  107 - 109 , thereby forming three diode pairs  104 / 107 ,  105 / 108 ,  106 / 109  that are connected in series between the first heat-sink and the second heat-sink. Leads that extend from the alternator&#39;s stator windings  101 ,  102 ,  103  are electrically connected to the cathode/anode connections of the diode pairs  104 / 107 ,  105 / 108 ,  106 / 109 . A lead  116  to the voltage regulator is connected between a diode pair  106 / 109 . The lead  116  is also optionally connected to an electric choke (not shown) if an electric choke is used. Output terminals  115  from the first heat sink are coupled to the positive post  111  of the battery  114  by a fusible link  113 . An output terminal  118  in FIG. 1 represents the connection from the second heat sink to the common ground when the alternator with the rectifier bridge circuit  100  is installed on an engine. The common ground is also connected to the negative post  112  of the battery  114  to complete the circuit from the rectifier bridge circuit  100  to the battery  114 .  
         [0059]    [0059]FIG. 2 illustrates a rectifier bridge circuit  200  that includes thermal safety disconnect elements  201 - 206  (herein after “disconnect elements”) in accordance with the present invention. The disconnect elements  201 - 206  are coupled along the potential circuit paths from the positive terminal  111  to the negative terminal  112  of the battery  114 . The disconnect elements  201 - 206  are coupled in series with the circuit paths of the diodes  104 - 109 , adjacent to each diode. The arrows along the circuit lines in FIG. 2 illustrate the direction of voltage drop when current flows through the failed diodes. For example, a first disconnect element  201  is in the circuit path associated with a first diode  104 . The first disconnect element  201  is responsive to the heat dissipated from the first diode  104  such that the first disconnect opens the circuit path when the first diode overheats. Generally, the disconnect elements  201 - 206  are located in positions where the heat dissipated from the failed diodes  104 - 109  can best be sensed. A special disconnect element  208  is used to open the circuit associated with the lead  116  to the voltage regulator and to the electric choke.  
         [0060]    A first diode  104  and a second diode  108  are highlighted to illustrate the current path from the positive terminal  111  through the two failed diodes, and the stator coils  101 ,  102 , to the negative terminal  112 . As may be appreciated, current from the stator assembly can flow in the reverse direction to the ground when a pair of diodes fail. During a failure of the two highlighted diodes  104 ,  108 , the heat generated by the diodes, as a result of the excess current, melts the adjacent disconnect elements  201 ,  205  to open the circuit path of the diodes. The stator coils  101 ,  102 ,  103  along with the six diodes  104 - 109 , and the “S” lead  116 , provide twelve possible paths to ground.  
         [0061]    [0061]FIG. 3A illustrates the circuit arrangement of a Ford 3G alternator. The rectifier circuit includes eight diodes  304 - 311  that form four diode pairs  304 / 307 ,  305 / 306 ,  308 / 309 , and  310 / 311 . The diode pairs  304 / 307 ,  305 / 306 ,  308 / 309 ,  310 / 311  are coupled to the stator coils  301 - 303  and to the battery terminals (not shown) in a similar manner as the diode pairs and stator coils of FIG. 1. The fourth diode pair  305 / 306  provides a connection from the center of the dual “Y” stator.  
         [0062]    [0062]FIG. 3B illustrates the Ford 3G alternator circuit of FIG. 3A after undergoing modifications to include disconnect elements  336 . The disconnect elements  336  are provided adjacent to each diode so as to control the flow of current through the associated diode. The disconnect elements  336  cut the flow of current in the associated circuit when the corresponding diode overheats.  
         [0063]    As discussed below in connection with FIGS. 4A, 4B, and  5 A, the disconnect elements used in the circuit of FIG. 2 and in the circuit of FIG. 3B are preferably safety spacer washers that have an inside diameter of approximately  0 . 06  inch, an outside diameter of approximately 0.22 inch, and a thickness of approximately 0.1 inch. Alternatively, the thickness is approximately 0.06 inch. The safety washers are advantageously made out of tin that has a negligible electrical resistance and that has a melting temperature of approximately 232 degrees centigrade. The dimensions of the safety washer may also vary with the location within the rectifier assembly.  
         [0064]    [0064]FIG. 4A illustrates a rectifier assembly  425  with the disconnect elements of the present invention. The rectifier assembly  425  is preferably made of brass, or beryllium, that is bent, or is formed, to shape. The rectifier assembly  425  includes a connector assembly  429  which has two corrugated B+terminals  431 A,  431 B that are guided into a phenolic type housing  426 . An alignment rail  427  aligns and polarizes the female connector (not shown) from the automobile wiring harness. When fully engaged, the locking ramps  428  secure the corrugated terminals  431 A,  431 B to the female connector. The corrugated terminals  431 A,  431 B are discussed in further detail below with reference to FIG. 18.  
         [0065]    A third terminal  430 , generally referred to as the “S” sensing terminal, is fitted with a safety washer  437 . The “S” terminal  430  fits into a third slot in the rectifier assembly  425 . The “S” terminal  430  is coupled to a first set of semiconductors,  106 ,  109 , via a pair of terminal brackets,  434 / 435 . The “S” terminal  430  is formed in a corrugated configuration so as to increase its width and ensure proper connection with potentially worn out connectors. The safety washer  437  melts when overheated to disconnect the “S” sensing terminal. The safety washer  437  corresponds to the special disconnect  208  in FIG. 2.  
         [0066]    The pair of terminal brackets  434 / 435 ,  443 / 444 ,  445 / 446  are coupled together by safety washers  436 A,  436 B,  436 C. A first set of terminal brackets  434 / 435  is pressed against the diode contacts of a first pair of diodes  106 / 109  by an insulated compression spring  438 A. The first set of terminal brackets  434 / 435  is held together by a safety washer  436 A that is soldered to the terminal brackets. A second diode pair  105 / 108  is coupled to a second set of terminal brackets,  443 / 444  by a spring  438 B and by a safety washer  136 B. A third diode pair  104 / 107  is coupled to a third set of terminal brackets  445 / 446  by a spring  438 C and by a safety washer  136 C. Four hold-down screws  454 , inserted through four nylon bushings  450 , secure the rectifier assembly  425 , the terminal plate  429 , the positive heat sink  451 , a gasket  452 , and the negative heat sink  453  to the alternator body.  
         [0067]    [0067]FIG. 4B is a side view of an arrangement of a diode pair assembly that is used in the rectifier assembly of FIG. 4A. The diode pair assembly includes the safety washer  436 A, the insulated compression spring  438 A, the pair of terminal brackets  434 / 435 , and the pair of diodes  106 / 109 . The spring is preferably a Teflon® coated compression spring. As discussed above, the safety washer  436 A is soldered between the terminal brackets  434 / 435 . The safety washer  436 A provides a conductive path between the terminal brackets  434 / 435 . The two other diode pair assemblies of the rectifier assembly of FIG. 4A are similarly arranged.  
         [0068]    [0068]FIG. 5A illustrates a side view of the rectifier assembly  425  of FIG. 4A. The rectifier assembly  425  includes the rectifier assembly components of FIG. 4A when assembled together.  
         [0069]    In operation, the corresponding safety washer melts when a failed diode dissipates excessive heat. The melted safety washer opens the circuit path between the terminal brackets to disconnect the failed diode from its circuit paths. The terminal brackets are held apart by the compressed spring positioned between the terminal brackets.  
         [0070]    Although tin safety washers are used in the illustrated apparatus, various types of melting materials can be used. Further, the melting material may be configured as washers, tabs, or other shapes that suit the particular apparatus. Although the illustrated embodiment uses insulated compression springs and melting material, which force the failed circuit to disconnect by disconnecting both the positive semiconductor and the negative semiconductor, a similar effect can be achieved by only disconnecting one semiconductor of a conducting pair to open the circuit to ground, for example.  
         [0071]    [0071]FIG. 5B is a second perspective view of an assembled rectifier that includes the components of FIG. 4A. The two B+parallel terminals  429  are formed to receive the female connector from the automobile wiring harness. The stator coils  101 ,  102 ,  103  (shown pictorially) are coupled to the rectifier assembly  425  by a connector  563  that mates with the terminal brackets  446 ,  444 ,  435 . Thus, the stator coils  101 ,  102 ,  103  are coupled to the bracket terminals  446 ,  444 ,  435  that provide the common connection points between the diodes in the diode pairs.  
         [0072]    [0072]FIG. 5C illustrates the capacitor module of the rectifier assembly of FIG. 4A. A capacitor  510  is coupled to the positive heat sink  451  by a screw  454  and a nylon bushing  450 . The capacitor  510  includes a first connector ring  561  and a second connector ring  562  to couple the capacitor between the positive terminal  111  and the negative terminal  112  of the battery, as is illustrated in FIG. 1.  
         [0073]    [0073]FIG. 6 illustrates a diode  106  with a spring pull-off thermal safety release. The apparatus utilizes terminals that include spring-loaded contacts, which disconnect when a diode overheats. A lead  602  has a first end that defines a nail head contact  686 . The lead  602  extends through an opening in a circuit terminal  634 . The circuit terminal  634  is adapted to rest on the diode  106  without touching the diode&#39;s electrical contact  696 . As may be appreciated from FIG. 6, the terminal body  695  is thus insulated from the diode&#39;s electrical contact  696 .  
         [0074]    The nail head contact  686  is soldered to the diode&#39;s electrical contact  696  by a low melting point solder  681 . The lead  602  is soldered to the terminal body  695  by using a higher melting point solder  685  than that which was used to couple the nail head contact  686  to the diode&#39;s electrical contact  696 . A clearance  699  within the circuit terminal  634  allows for the release of the nail head contact  686  from the diode&#39;s electrical contact  696  when the solder  681  melts.  
         [0075]    A second end  680  of the lead  602  is shaped into an arrow head. The second end  680  of the lead  602  extends from a small opening in a conical spring  672  such that the spring is compressed by the second end  680  of the lead  602 .  
         [0076]    In operation, the terminal assembly is used to open the circuit associated with a diode when the diode generates heat in excess of a threshold. The heat radiated by a failed diode  106  increases the temperature of the low melting point solder  681  between the nail head contact  686  and the diode&#39;s electrical contact  696 . The increase in temperature causes the low melting point solder  681  to melt. Although, the higher melting point solder  685  remains solid, it only has sufficient mechanic strength to hold the lead  602  in place adjacent to the face of the spring  672  when the low melting point solder  681  is also solid. Thus, when the low melting point solder  681  melts in response to the high temperature, the pressure applied to the second end of the lead  602  by the spring  672  forces the nail head contact  686  away from the diode&#39;s electrical contact  696 . The electrical connection between the lead  602  and the diode  106  is thereby opened. Further, the electrical connection between the diode  106  and the terminal  634  is also opened because the terminal is electrically connected to the diode only by the lead  602 .  
         [0077]    [0077]FIG. 7A illustrates a pan-type semiconductor terminal assembly. The semiconductor diode  783  is nested in a cavity  779  of a heat sink  751 . A safety washer  736  is pressed against a stator terminal  734  by a spring  738 . A lead  780  extends from the diode&#39;s contact through the safety washer  736 . Solder  781  is used to couple the lead  780  to the stator terminal  734  and to the safety washer  736 .  
         [0078]    [0078]FIG. 7B illustrates the terminal assembly of FIG. 7A after an overheated condition that causes a failure. When the semiconductor diode  783  overheats, the solder  781  and the safety washer  736  melt. The removal of the solder  781  opens the diode&#39;s electrical circuit because the diode  783  is electrically coupled to the stator terminal  734  by the solder and the spring  738  is electrically insulated.  
         [0079]    [0079]FIG. 7C illustrates a diode pair assembly which employs low melting point solder to open the overheated diode circuit. The diode pair assembly includes a first diode  106 , a second diode  109 , a terminal bracket  702 , a first insulated compression spring  706 , and a second insulated compression spring  710 . The first diode  106  is located within a cavity in the base of the diode pair assembly. The first diode  106  is mechanically held against the base of the diode pair assembly by a first portion  703  of a terminal bracket  702 . The first portion  703  of the terminal bracket  702  is positioned over the first diode  106 . The first portion  703  of the terminal bracket  702  is forced downward towards the first diode  106  by the first compression spring  706 . The first compression spring  706  is positioned between the terminal bracket  702  and the bottom portion of the connector locking ramp  428  (FIG. 4). The second diode  109  is positioned below a second portion  705  of the terminal bracket  702 . The second portion  705  of the terminal bracket  702  is held in place on top of the second diode  109  by a low melting point solder  708 . The low melting point solder  708  mechanically and electrically connects the second portion  705  of the terminal bracket  702  to a stator terminal  709 . A second compression spring  710  is positioned below the center portion of the terminal bracket  702 . The second compression spring  710  is secured by a pin  707 . The pin  707  extends through an opening in the terminal bracket  702  and an opening in the heat sink.  
         [0080]    In operation, when a diode fails and overheats, the low melting point solder  708  melts to disconnect the second portion  705  of the terminal bracket  702  from the stator terminal  709 . The second compression spring  710  forces the second portion  705  of the terminal bracket  702  away from the stator terminal  709 . Thus, the electrical circuit between the first diode  106 , the second diode  109 , and the stator terminal  709  is opened.  
         [0081]    [0081]FIG. 8A illustrates a semiconductor diode  892  prior to being pressed into a heat sink  891 . A lead  880  from the diode  892  extends through a safety washer  836 . The lead  880  is coupled to the safety washer  836  by a low melting point solder  881 . The solder  881  and the washer  836 , provide an electrical connection between the diode  892  and the stator terminal  834 , which is opened when the rectifier assembly overheats.  
         [0082]    [0082]FIG. 8B illustrates the semiconductor diode  892  as installed in the heat sink  891 . As may be appreciated from FIG. 8B, when installed the lead  880  is soldered in place, and is under compression.  
         [0083]    [0083]FIG. 8C illustrates the semiconductor diode  892  after an overheat condition. When the diode  892  overheats, the solder  881  and the safety washer  836  melt. The cleared solder  881  creates a gap between the lead  880  and the stator terminal  834  to open the circuit connection from the diode to the stator terminal  834 . Thus, the arrangement of FIGS. 8A, 8B, and  8 C eliminates the use of the spring underneath the washer in the arrangement of FIGS.  7 A, and  7 B.  
         [0084]    As discussed below in connection with FIG. 9 and FIG. 10, in another embodiment, a copper cup press fit semiconductor diode is coupled to a protective cup by a tin/copper type low resistance, low melting temperature, metal spacer disc that is soldered to the semiconductor contact surface. When the semiconductor fails and becomes an electrical heater instead of a switching and blocking device, the spacer disc melts and opens the circuit. A collection area within the copper cup provides room for the melted metal to clear the diode contact surface.  
         [0085]    [0085]FIG. 9 illustrates a rectifier press fit semiconductor diode assembly with thermal disconnect. A silicon semiconductor chip  902  is coupled to a platform  912  in the bottom of the cup  900 . A thermal safety disc  913  is coupled to the electrical contact of the chip  902 . The lower end  906  of an axial lead  905  is coupled to the thermal safety disc  913  via solder  914 . The upper end of the axial lead  905  extends up through an insulator  907 , which is then sealed with epoxy  904 . The upper end of the axial lead  905  is affixed to the rectifier bridge circuit terminal  909  by solder  910 .  
         [0086]    [0086]FIG. 10 illustrates the diode assembly of FIG. 9 after the thermal safety disc  936  has melted away from the semiconductor, leaving an open circuit between the semiconductor  902  and the lower end of the axial lead  906 . A collection area  903  allows the melted disc  913  and solder  914  to flow away from the semiconductor contact area.  
         [0087]    In another embodiment, shown in FIG. 11 and in FIG. 12, a conical compressed spring is affixed to an axial lead. The opposite end of the spring is compressed against the insulating material of the pan cup. The spring is preloaded so as to pull the semiconductor contact away when the solder melts. This action stops the current flow through the semiconductor circuit. Prior to opening the circuit, the generated heat conducts up along the axial lead from the semiconductor to melt the soldered lead of the rectifier bridge terminal. This allows the lead to be forced upwards, to open the semiconductor circuit.  
         [0088]    [0088]FIG. 11 illustrates a pan-type diode assembly, which includes a semiconductor  1102  affixed to the inside of a copper pan  1100  by solder  1112 . The nail head  1120  of the axial lead  1105  is affixed to the semiconductor  1102  by solder  1112 . The axial lead  1105  terminates at the rectifier bridge terminal  1109  and is soldered using a lower melting temperature solder  1110 . A locking clip  1118  is used to lock a compression spring  1117  to a bend  1115  in the axial lead  1105 .  
         [0089]    [0089]FIG. 12 illustrates the pan type rectifier diode assembly of FIG. 11 in a failed, overheated condition. Excessive heat from the reverse current flow causes the solder  1112  to melt at the connection point between the nail head  1120  and the semiconductor  1102 . The heat also melts the solder  1110  at the opposite end of the lead  1105  to allow the compression spring  1117  to push the axial lead  1105  up through the terminal  1109 . The nail head  1120  is thus allowed to lift off the semiconductor  1102  and open the circuit between the semiconductor and the axial lead  1105 . Once the circuit is opened, the current flow is stopped. The compression spring  1117  pushes the clip  1118  upward at the stress relief bend  1115  of the axial lead  1105  and pushes the potting material  1116  upward to open the internal circuit of the cup assembly.  
         [0090]    [0090]FIG. 13A illustrates an alternate embodiment of a diode pair assembly  1301  employing safety washers. The diode pair assembly  1301  includes a first diode  1302 , a second diode  1304 , a terminal connector  1306 , a spring  1308 , and a safety washer  1312 . The first diode  1302  is coupled to the positive terminal of the diode pair assembly  1301  and to a first portion  1318  of the terminal connector  1306 . A second portion  1314  of the terminal connector  1306  is coupled to the second diode  1304 . The terminal connector  1306  rests on the second diode  1304  by using a plurality of standoffs  1317  that maintain the diode&#39;s electrical contact spaced apart from the second portion  1314  of the terminal connector. A safety washer  1312  is positioned below the spaced apart terminal connector  1306 . The spring  1308  is placed between the portions  1314 ,  1318  of the terminal connector  1306  to maintain the portions of the terminal connector spaced apart from one another. A circuit terminal  1316  is formed at an end of the terminal connector  1306 . Solder  1310  is used to connect the diodes  1302 ,  1304  to the safety washer  1312  and to the terminal connector  1306 . FIG. 13B illustrates the components of the diode pair assembly  1301  when assembled together between a positive heat sink  1320  and a negative heat sink  1322 . An insulating gasket  1324  separates the positive heat sink  1320  and the negative heat sink  1322 .  
         [0091]    In operation, the diode pair assembly disconnects the electrical connection between the diodes  1302 ,  1304  when the level of heat absorbed by the safety washer  1312  melts the safety washer. The safety washer  1312  facilitates the electrical connection between the second diode  1304  and the terminal connector  1306 . Thus, when the washer  1312  melts, the electrical connection between the diode  1304  and the terminal connector is eliminated. The electrical connection between the diode  1304  and any other component of the diode pair is also eliminated. Therefore, the diode pair assembly  1302  provides a thermally safe connection between two diodes.  
         [0092]    [0092]FIG. 14 illustrates a diode pair assembly  1401  that employs a meltable terminal connector. The embodiment of FIG. 14 eliminates the safety washer from the assembly of FIGS. 13A and 13B. The diode assembly includes a first diode  1402 , a second diode  1404 , a circuit terminal  1406 , a connector terminal  1415 , and an optional insulated spring  1410 . The first diode  1402  is coupled to the circuit terminal  1406  and to a first end  1414  of the terminal connector  1415  by solder  1416 . The second end  1412  of the terminal connector  1415  is coupled to the second diode  1404  by solder  1416 . An optional spring  1410  may be provided between the ends  1412 ,  1414  of the terminal connector  1415  to separate the diodes  1402 ,  1404  from one another when the terminal connector melts away. In operation, when the diodes  1402 ,  1404  overheat, the terminal connector  1415  melts so as to disconnect the circuit path between the diodes.  
         [0093]    [0093]FIG. 15 illustrates another embodiment of the safety disconnects of the present invention. The diodes  1501 , 1502  are coupled together by an L-shaped bracket  1504  and a low melting point connection plate  1505 . The L-shaped bracket  1504  is soldered to the connection plate  1505  to secure a compressed spring  1503  between the diode pair  1501 / 1502 . The circuit path of the diode pair  1501 / 1502  flows through the connection plate  1505 . When a diode overheats, the connection plate  1505  melts to open the connection. The spring pushes the diodes  1501 ,  1502  away from one another. The use of a melting connection plate  1505  advantageously eliminates the safety washers from the rectifier assembly.  
         [0094]    [0094]FIG. 16 illustrates the positive heat-sink  451  of FIGS. 4A and 5A. The positive heat sink  451  includes a vertical bent portion and a horizontal base portion. The vertical bent portion includes cavities  455  for securing the diodes of the rectifier assembly  425  in position.  
         [0095]    [0095]FIG. 17 illustrates the negative heat sink  453  of FIGS. 4A and 5A. The negative heat sink  453  includes a vertical bent portion and a horizontal base portion. The horizontal base portion in intended to serve as the bottom element in the rectifier assembly configuration that is illustrated in FIG. 4A. As may be appreciated, the elements that are stacked on the negative heat sink  453  to form the rectifier assembly body include, in order, the gasket  452 , the positive heat sink  451 , and the terminal connector assembly  429 . The vertical bent portion of the negative heat sink  453  includes cavities  457  for securing the diodes of the rectifier assembly  425  in position.  
         [0096]    [0096]FIG. 18 illustrates the terminal connector  429  of FIGS. 4A and 5A. The terminal connector  429  is used to couple the female wiring harness to the rectifier assembly as illustrated in FIG. 4A. The terminal connector incorporates self-aligning corrugated terminal blades  431 A,  431 B that are formed with a plurality of bends to allow for a variation in the lateral spacing in a female connector. An additional large bend  460  at the base of each blade  431 A,  431 B provides additional flexibility with respect to the positions of the two blades. For example, a worn-out female harness may be spaced wider than a new female harness. The terminal connector  429  can mate with such a worn-out connector because of the effective thicknesses of the blades provided by the corrugation and because the bends  460  at the base of the blades allow the blades to adapt to different positions of the mating connectors.  
         [0097]    The connector material is a tempered half-hard beryllium, approximately 0.031 inches thick. The connector  429  conducts the required current without overheating. The connector&#39;s temper allows it to spring back into any usable position to accommodate all connectors used in the alternator application. The corrugated terminal blades  431 A,  431 B include a plurality of detents or alternating dimples, approximately 0.125 inch from centerline to centerline, which expands the connector&#39;s contact gripping thickness from 0.031 inches to approximately 0.037 inches.  
         [0098]    In use, the female connector is pushed into the terminal connector  429  to secure the corrugated blades  431 A,  431 B to grooves in the female connector. The corrugated blades  431 A,  431 B are thick enough so as to securely reside within the grooves of the female connector. The female connector is further held in place by a pair of detents on the terminal cover as discussed with reference to FIG. 4A. Thus, the irregularly shaped male blades allow for the terminal  429  to properly couple to a female connector after the connector has been removed from an original rectifier and may have become distorted or worn-out. The terminal connector  429  of the present invention does not increase the likelihood that the connector will fail.  
         [0099]    [0099]FIG. 19 illustrates an insulating gasket  452  that is used in the rectifier of the present invention. The insulator gasket  452  is stamped out of a fiberglass reinforced, phenolic-type material, which is approximately 0.012 inches thick and has a compression strength of 65,000 psi (pounds per square inch). The gasket  452  separates the two copper heat sinks  451 ,  453 , from one another. The inside area of the gasket  452  is stamped out to form two openings  458 . During assembly of the rectifier, the openings  458  in the gasket  452  are filled with a thermally conductive (i.e., heat transferring), electrically non-conductive grease to enhance the transfer of a portion of the generated heat to the alternator housing.  
         [0100]    Although the invention has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments which do not provide all of the features and advantages set forth herein, are also within the scope of this invention. Accordingly, the scope of the invention is defined by the claims that follow.