Patent Publication Number: US-11387061-B2

Title: Passive triggering mechanisms for use with switching devices incorporating pyrotechnic features

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of, and claims the benefit of, U.S. patent application Ser. No. 16/114,082 to Murray Stephan McTique, et al., entitled Passive Triggering Mechanisms for Use with Switching Devices Incorporating Pyrotechnic Features, filed on Aug. 27, 2018, which in turn is a continuation-in-part of, and claims the benefit of, U.S. patent application Ser. No. 16/101,143 to Daniel Sullivan, et al., entitled Contactor Device Integrating Pyrotechnic Disconnect Features, filed on Aug. 10, 2018, which in turn is a continuation-in-part of, and claims the benefit of, U.S. application Ser. No. 15/889,516 to Murray Stephan McTigue, et al., entitled Mechanical Fuse Device, filed on Feb. 6, 2018, which in turn is a continuation-in-part of, and claims the benefit of, U.S. application Ser. No. 15/146,300 to Murray Stephan McTique, et al., entitled Mechanical Fuse Device, filed on May 4, 2016, which in turn claims the benefit of U.S. Provisional Application Ser. No. 62/163,257 to Murray S. McTigue, et al., entitled Mechanical Fuse Device, filed on May 18, 2015. U.S. application Ser. No. 15/889,516, U.S. application Ser. No. 16/101,143, and U.S. application Ser. No. 16/114,082, each further claims the benefit of U.S. Provisional Application 62/612,988 to Daniel Sullivan, et al., entitled Contactor Device Integrating Pyrotechnic Disconnect Features, filed on Jan. 2, 2018. The present application is also a continuation-in-part of, and claims the benefit of, U.S. application Ser. No. 15/889,516 to Murray Stephan McTigue, et al., entitled Mechanical Fuse Device, filed on Feb. 6, 2018, which claims the benefit of U.S. Provisional Application 62/612,988 to Daniel Sullivan, et al., entitled Contractor Device Integrating Pyrotechnic Disconnect Features, filed on Jan. 2, 2018; and U.S. application Ser. No. 15/889,516 is a continuation-in-part of, and claims the benefit of, U.S. application Ser. No. 15/146,300 to Murray Stephan McTique, et al., entitled Mechanical Fuse Device, filed on May 4, 2016, which in turn claims the benefit of U.S. Provisional Application Ser. No. 62/163,257 to Murray S. McTigue, et al. Each of the above-listed applications are hereby incorporated herein in their entirety by reference. 
    
    
     BACKGROUND 
     Field of the Invention 
     Described herein are devices relating to triggering mechanisms and configurations for use with electrical switching devices, such as contactor devices and electrical fuse devices. 
     Description of the Related Art 
     Connecting and disconnecting electrical circuits is as old as electrical circuits themselves and is often utilized as a method of switching power to a connected electrical device between “on” and “off” states. An example of one device commonly utilized to connect and disconnect circuits is a contactor, which is electrically connected to one or more devices or power sources. A contactor is configured such that it can interrupt or complete a circuit to control electrical power to and from a device. One type of conventional contactor is a hermetically sealed contactor. 
     In addition to contactors, which serve the purpose of connecting and disconnecting electrical circuits during normal operation of a device, various additional devices can be employed in order to provide overcurrent protection. These devices can prevent short circuits, overloading, and permanent damage to an electrical system or a connected electrical device. These devices include disconnect devices which can quickly break the circuit in a permanent way such that the circuit will remain broken until the disconnect device is repaired, replaced, or reset. One such type of disconnect device is a fuse. A conventional fuse is a type of low resistance resistor that acts as a sacrificial device. Typical fuses comprise a metal wire or strip that melts when too much current flows through it, interrupting the circuit that it connects. 
     As society advances, various innovations to electrical systems and electronic devices are becoming increasingly common. An example of such innovations include recent advances in electrical automobiles, which may one day become the energy-efficient standard and replace traditional petroleum-powered vehicles. In such expensive and routinely used electrical devices, overcurrent protection is particularly applicable to prevent device malfunction and prevent permanent damage to the devices. Furthermore, overcurrent protection can prevent safety hazards, such as electrical fires. These modern improvements to electrical systems and devices require modern solutions to increase convenience and efficiency of mechanisms for triggering fuse devices. 
     SUMMARY 
     Described herein are passive triggering features and configurations for the activation of pyrotechnic features to function as a fuse mechanism within switching devices, such as contactors or fuse devices. These passive triggering configurations can be configured to trigger in response to a threshold magnetic field strength, corresponding to a threshold level of current flowing through the device corresponding to a dangerous overcurrent. The threshold level of current required to trigger these passive triggering configurations can be related to the distance between a passive triggering mechanism, such as a reed switch, and a portion of the device, such as a power terminal or feature connected to a power terminal. 
     In one embodiment, an electrical switching device comprises a housing and internal components within the housing configured to change the state of said switching device from a closed state allowing current flow through said switching device to an open state which interrupts current flow through said switching device. The switching device also comprises pyrotechnic features configured to interact with the internal components to transition the switching device from the closed state to the open state when said pyrotechnic features are activated, and a passive trigger switch structure configured to activate the pyrotechnic features when triggered. The passive trigger switch structure is configured to trigger in response to a magnetic field reaching a threshold strength when a threshold current level flows through the switching device. The switching device also comprises power terminals electrically connected to the internal components for connection to external circuitry. 
     In another embodiment, an electrical switching device comprises a housing and internal components comprising fixed contacts electrically isolated from one another at least partially surrounding by the housing and one or more moveable contacts allowing current flow between the fixed contacts when the one or more moveable contacts are contacting said fixed contacts. The switching device further comprises a shaft structure connected to the moveable contacts and pyrotechnic features configured move the one or more moveable contacts out of contact with the fixed contacts when the pyrotechnic features are activated. The switching device further comprises a passive trigger switch structure configured to activate the pyrotechnic features when triggered and configured to trigger in response to a magnetic field reaching a threshold strength when a threshold current level flows through the switching device. The switching device further comprises power terminals electrically connected to the internal components for connection to external circuitry. 
     In yet another embodiment, an electrical switching device comprise a housing and internal components within the housing configured to change the state of the switching device from a closed state allowing current flow through the switching device to an open state which interrupts current flow through the switching device. The electrical switching device further comprises pyrotechnic features configured to interact with the internal components to transition the switching device from the closed state to said open state when said pyrotechnic features are activated. The pyrotechnic switching device further comprises an external triggering mechanism comprising a passive trigger switch structure, a conductive bus bar and a non-magnetic spacer portion. The non-magnetic spacer portion spaces the passive trigger switch structure from the conductive bus bar, such that the passive trigger switch structure is configured to trigger in response to a magnetic field reaching a threshold strength when a threshold current level flows through the switching device. This allows an electrical signal to flow through the external triggering mechanism to activate said pyrotechnic features. The switching device further comprises power terminals electrically connected to the internal components for connection to external circuitry. 
     These and other further features and advantages of the invention would be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, wherein like numerals designate corresponding parts in the figures, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front sectional view of an embodiment of a contactor able to incorporate features of the present invention, shown in the “closed” orientation that allows flow of electricity through the device; 
         FIG. 2  is a front sectional view of the embodiment of the contactor device of  FIG. 1 , shown in an “open” or “disconnected” orientation that prevents flow of electricity through the device; 
         FIG. 3  is a front sectional view of the embodiment of the contactor device of  FIG. 1 , shown in a different orientation, wherein the disconnect elements have been “triggered;” 
         FIG. 4  is a front sectional view of a fuse device able to incorporate features of the present invention, shown in the resting “un-triggered” state; 
         FIG. 5  is a front sectional view of a fuse device able to incorporate features of the present invention, shown in the activated “triggered” state; 
         FIG. 6  is a front, top, perspective view of a pyrotechnic triggering configuration incorporating features of the present invention; 
         FIG. 7  is a back, top view of the pyrotechnic triggering configuration of  FIG. 6 ; 
         FIG. 8  is a front, top, perspective view of another pyrotechnic triggering configuration incorporating features of the present invention; 
         FIG. 9  is a back, top view of the pyrotechnic triggering configuration of  FIG. 8 ; 
         FIG. 10  is a front, top, perspective view of yet another pyrotechnic triggering configuration incorporating features of the present invention; and 
         FIG. 11  is front sectional view of a portion of the pyrotechnic triggering configuration of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will now set forth detailed descriptions of various embodiments. These embodiments set forth passive switching features and configurations for use with switching devices, such as contactors or fuse devices, integrating pyrotechnic circuit breaking features. These switching devices can be electrically connected to an electrical device or system to turn power tot eh connected device or system “on” or “off.” While the example devices disclosed here can utilize active triggering configurations in addition to, or in lieu of, the disclosed passive features, the passive features provide the advantage of automatically triggering a pyrotechnic circuit break in response to a threshold current level. 
     In some embodiments, a printer circuit board (PCB) or an external triggering mechanism is configured to direct a signal toward pyrotechnic pins in communication with a pyrotechnic charge. Power for this signal to trigger the pyrotechnic features of the switching device can be provided by a separate power source (i.e. a power source other than the power source of the device or electrical system to which the switching device is connected) or power for the signal can be provided or diverted from the power source of the device or electrical system to which the switching device is connected. The pyrotechnic charge is configured to function as a fuse, permanently breaking the circuit through the contactor or fuse device, for example, by moving moveable contacts out of contact with fixed contacts. 
     The PCB or external triggering mechanism incorporates a passive trigger switch, such as a reed switch, that is open in its resting state, preventing the triggering signal from being sent to the pyrotechnic pins and therefore allowing current to flow through the device. The passive trigger switch can be configured to trigger in response to a magnetic field of sufficient strength, which can be calculated to correspond to a desired threshold level of current though the device, for example, a hazardous overcurrent. As the required threshold strength of the magnetic field required to trigger the passive trigger switch depends on the proximity of the passive trigger switch to the source of the magnetic field, the passive trigger switch can be configured as a “proximity switch.” This allows the desired trip current to be set based upon the distance between the passive trigger switch and a region of the device, such as one of the power terminals. 
     In other embodiments, additional features can be included. For example, a ferrous core structure can be positioned at least partially surrounding one of the power terminals of the switching device and the trip current can be determined by the distance between the core structure and the passive trigger switch. In some embodiments, external triggering mechanisms can be utilized, which can incorporate a conductive bus portion and a passive trigger switch spaced from the conductive bus portion by a non-magnetic spacer portion. In these embodiments, the trip current can be determined by the thickness of the non-magnetic spacer portion. 
     Throughout this description, the preferred embodiment and examples illustrated should be considered as exemplars, rather than as limitations on the present invention. As used herein, the term “invention,” “device,” “present invention,” or “present device” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “invention,” “device,” “present invention,” or “present device” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s). 
     It is also understood that when an element or feature is referred to as being “on” or “adjacent” to another element or feature, it can be directly on or adjacent to the other element or feature or intervening elements or features may also be present. It is also understood that when an element is referred to as being “attached,” “connected” or “coupled” to another element, it can be directly attached, connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly attached,” “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
     Relative terms, such as “outer,” “above,” “lower,” “below,” “horizontal,” “vertical” and similar terms, may be used herein to describe a relationship of one feature to another. It is understood that these terms are intended to encompass different orientations in addition to the orientation depicted in the figures. 
     Although the terms first, second, etc. may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are only used to distinguish one element or component from another element or component. Thus, a first element or component discussed below could be termed a second element or component without departing from the teachings of the present invention. 
     The terminology used herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Embodiments of the invention are described herein with reference to different views and illustrations that are schematic illustrations of idealized embodiments of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances are expected. Embodiments of the invention should not be construed as limited to the particular shapes of the regions illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. 
     It is understood that when a first element is referred to as being “between,” “sandwiched,” or “sandwiched between,” two or more other elements, the first element can be directly between the two or more other elements or intervening elements may also be present between the two or more other elements. For example, if a first element is “between” or “sandwiched between” a second and third element, the first element can be directly between the second and third elements with no intervening elements or the first element can be adjacent to one or more additional elements with the first element and these additional elements all between the second and third elements. 
     Before describing specific pyrotechnic triggering configurations incorporating features of the present invention in detail, example switching devices incorporating pyrotechnic features and providing example environments for passive triggering configurations according to the present disclosure will first be described. These switching devices can include any switching devices incorporating pyrotechnic features, for example, contactors configured to allow switching of a device between an “on” and “off” state. 
     In some contactor devices, the pyrotechnic features function as a fuse element incorporated into the contactor device. Examples of such contactor devices are set forth in U.S. application Ser. No. 16/101,143, entitled Contactor Device Integrating Pyrotechnic Disconnect Features, which is assigned to Gigavac, Inc., the assignee of the present application and which is incorporated by reference into the present application. In addition to contactors configured to freely switch between “on” and “off” states, pyrotechnic triggering configurations according to the present disclosure can also be utilized with sacrificial fuse devices that are configured to allow current through an electrical system or device when not triggered, and to prevent current through the electrical system or device when triggered. Examples of such fuse devices are set forth in U.S. application Ser. No. 15/889,516, entitled MECHANICAL FUSE DEVICE, which is assigned to Gigavac, Inc., the assignee of the present application and which is incorporated by reference into the present application. 
     In reference to an example contactor device incorporating pyrotechnic features,  FIG. 1  shows a sectional view of an example embodiment of a contactor device  100 , which comprises an integrated pyrotechnic disconnect component which can function as a sacrificial disconnect in the event of overcurrent.  FIG. 1  shows the contactor device  100  in a “closed” circuit position, wherein flow of electricity through the contactor device is enabled.  FIG. 1  further shows the pyrotechnic disconnect portion of the contactor device  100  in its non-triggered or “set” mechanical orientation, allowing the contactor device to function normally to operate between its “closed” and “open” position. The disconnect portion of the contactor device  100  also has a “triggered” orientation, where the circuit is broken and the flow of electricity through the contactor device is permanently disabled until the device is replaced or repaired and reset. Both the “closed” and “open” contactor modes and the “set” and “triggered” disconnect modes are described in more detail further herein. 
     The contactor device  100  of  FIG. 1  comprises a body  102  (also referred to as a housing  102 ), and two or more fixed contact structures  104 ,  106  (two shown) which are configured to electrically connect the internal components of the contactor device to external circuitry, for example, to an electrical system or device. The body  102  can comprise any suitable material that can support the structure and function of the contactor device  100  as disclosed herein, with a preferred material being a sturdy material that can provide structural support to the contactor device  100  without interfering with the electrical flow through the fixed contacts  104 ,  106  and the internal components of the device. In some embodiments, the body  102  comprises a durable plastic or polymer. The body  102  at least partially surrounds the various internal components of the contactor device  100 , which are described in more detail further herein. 
     The body  102  can comprise any shape suitable for housing the various internal components including any regular or irregular polygon. The body  102  can be a continuous structure, or can comprise multiple component parts joined together, for example, comprising a base body “cup,” and a top “header” portion sealed with an epoxy material. Some example body configurations include those set forth in U.S. Pat. Nos. 7,321,281, 7,944,333, 8,446,240 and 9,013,254, all of which are assigned to Gigavac, Inc., the assignee of the present application, and all of which are hereby incorporated in their entirety by reference. 
     The fixed contacts  104 ,  106  are configured such that the various internal components of the contactor device  100  that are housed within the body  102  can electrically communicate with an external electrical system or device, such that the contactor device  100  can function as a switch to break or complete an electrical circuit as described herein. The fixed contacts  104 ,  106  can comprise any suitable conductive material for providing electrical contact to the internal components of the contactor device, for example, various metals and metallic materials or any electrical contact material or structure that is known in the art. The fixed contacts  104 ,  106  can comprise single continuous contact structures (as shown) or can comprise multiple electrically connected structures. For example, in some embodiments, the fixed contacts  104 ,  106  can comprise two portions, a first portion extending from the body  102 , which is electrically connected to a second portion internal to the body  102  that is configured to interact with other components internal to the body as described herein. 
     The body  102  can be configured such that the internal space of the body  102 , which houses the various internal components of the contactor device  100 , is hermetically sealed. When coupled with the use of electronegative gas, this hermetically sealed configuration can help mitigate or prevent electrical arcing between adjacent conductive elements, and in some embodiments, helps provide electrical isolation between spatially separated contacts. In some embodiments, the body  102  can be under vacuum conditions. The body  102  can be hermetically sealed utilizing any known means of generating hermetically sealed electrical devices. Some examples of hermetically sealed devices include those set forth in U.S. Pat. Nos. 7,321,281, 7,944,333, 8,446,240 and 9,013,254, all of which are assigned to Gigavac, Inc., the assignee of the present application, and all of which are incorporated into the present application in their entirety by reference. 
     In some embodiments, the body  102  can be at least partially filled with an electronegative gas, for example, sulfur hexafluoride or mixture of nitrogen and sulfur hexafluoride. In some embodiments, the body  102  comprises a material having low or substantially no permeability to a gas injected into the housing. In some embodiments, the body can comprise various gasses, liquids or solids configured to increase performance of the device. 
     Before describing the pyrotechnic disconnect components of the contactor device  100  used for overcurrent protection, the contactor components utilized during ordinary switching use of the contactor device  100  will be described first. When not interacting with any of the other components internal to the body  102 , the fixed contacts  104 ,  106  are otherwise electrically isolated from one another such that electricity cannot freely flow between them. The fixed contacts  104 ,  106  can be electrically isolated from one another through any known structure or method of electrical isolation. 
     When the contactor device  100  is in its “closed” position, as shown in  FIG. 1 , both of the otherwise electrically isolated fixed contacts  104 ,  106  are contacted by a moveable contact  108 , such that the moveable contact  108  functions as a bridge allowing an electrical signal to flow through the device, for example, from the first fixed contact  104 , to the moveable contact  108 , to the second contact  106  or vice versa. Therefore, the contactor device  100  can be connected to an electrical circuit, system or device and complete a circuit while the moveable contact is in electrical contact with the fixed contacts. 
     The moveable contact  108  can comprise any suitable conductive material including any of the materials discussed herein in regard to the fixed contacts  104 ,  106 . Like with the fixed contacts  104 ,  106 , the moveable contact  108  can comprise a single continuous structure (as shown), or can comprise multiple component parts electrically connected to one another so as to serve as a contact bridge between the otherwise electrically isolated fixed contacts  104 ,  106 , so that electricity can flow through the contactor device  100 . 
     The moveable contact  108  can be configured such that it can move into and out of electrical contact with the fixed contacts  104 ,  106 , causing the circuit to be “closed” or completed when the moveable contact is in electrical contact with the fixed contacts  104 ,  106 , and to be “open” or broken when the moveable contact  108  is not in electrical contact with the fixed contacts  104 ,  106 , as the fixed contacts  104 ,  106  are otherwise electrically isolated from one another when not contacting the moveable contact  108 . In some embodiments, including the embodiment shown in  FIG. 1 , the moveable contact  108  is physically connected to a shaft structure  110 , which is configured to move along a predetermined distance within the contactor device  100 . The shaft  110  can comprise any material or shape suitable for its function as an internal moveable component that is physically connected to the moveable contact  108 , such that the moveable contact  108  can move with the shaft  110 . 
     Movement of the shaft  110  controls movement of the moveable contact  108 , which in turn controls the position of the moveable contact  108  in relation to the fixed contacts  104 ,  106 , which in turn controls flow of electricity through the contactor device  100  as described herein. Movement of the shaft can be controlled through various configurations, including, but not limited to, electrical and electronic, magnetic and solenoid, and manual. Example manual configurations for controlling a shaft connected to a moveable contact are set forth in U.S. Pat. No. 9,013,254, to Gigavac, Inc., the assignee of the present application, and all of which is incorporated into the present application in its entirety by reference. Some of these example configurations of manual control features include magnetic configurations, diaphragm configurations and bellowed configurations. 
     In the embodiment shown in  FIG. 1 , movement of the shaft  110  is controlled through the use of a solenoid configuration. A plunger structure  111  is connected to, or at least partially surrounds, a portion of the shaft  110 . The body  102  also houses a solenoid  112 . Many different solenoids can be used, with one example of a suitable solenoid being a solenoid operating under a low voltage and with a relatively high force. One example of a suitable solenoid is commercially available solenoid Model No. SD1564 N1200, from Bicron Inc., although many other solenoids can be used. In the embodiment shown, the plunger structure  111  can comprise a metallic material that can be moved and controlled by the solenoid  112 . Movement of the plunger structure  111  controls movement of the connected shaft  110 , which in turn controls movement of the connected moveable contact  108 . 
     The travel distance of the shaft  110  can be controlled utilizing various features, for example, springs to control travel/overtravel distance or various portions of the body  102  that can block or restrict the travel distance of the shaft  110 . In the embodiment shown in  FIG. 1 , the travel distance of the shaft  110  is partially controlled by a hard stop  113 , which is configured to abut against a winged portion  114  of the shaft  110 , to limit the distance of the shaft  110  when the shaft  110  has traveled a sufficient distance from the fixed contacts  104 ,  106 . The hard stop  113  can comprise any material or shape suitable for providing a surface to interact with the shaft  110  in order to limit the movement or travel distance of the shaft  110 . In the embodiment shown in  FIG. 1 , the hard stop  113  comprises a plastic material. In some embodiments, the hard stop  113  is configured to break or shear off when the pyrotechnic disconnect elements are triggered, as will be discussed in more detail further below. 
     Now that the basic switching features of the contactor device  110  have been set forth, the pyrotechnic disconnect elements will now be described. The contactor device  100  can comprise several elements that can function as overcurrent protection, including a pyrotechnic charge  202  and a piston structure  204 . The piston structure  204  can be positioned near or at least partially around one or more of the internal components, for example, the shaft  110  as shown, such that movement of the piston from a resting position can change the configuration of the internal components to interrupt flow of electricity through the device, for example, by pushing against or otherwise moving the shaft  100  as described herein. The pyrotechnic charge  202  can be configured such that it is activated when current exceeds a predetermined threshold level, in order to prevent permanent damage to a connected electric device or a safety hazard such as an electrical fire. 
     The contactor device  100  can comprise various sensor features that can detect when current through the device has reached a dangerous level and can trigger the pyrotechnic charge when this threshold level has been detected. In some embodiments, the contactor device  100  can comprise a dedicated current sensor configured to detect the level of current flowing through the device. The current sensor can be configured to directly or indirectly activate the pyrotechnic charge when the current has reached a threshold level. In some embodiments, the current sensors can transmit a signal proportional to the detected current to activate the pyrotechnic charge when a threshold current level is detected. In some embodiments, the current sensors can comprise a Hall effect sensor, a transformer or current clamp meter, a resistor, a fiber optic current sensor, or an interferometer. 
     In some embodiments, the pyrotechnic charge  202  is configured to be activated by electrical pulse and is driven by an airbag system configured to detect multiple factors, similar to that utilized in modern vehicles. In some embodiments, the contactor device  100  can comprise one or more pyrotechnic pins  203  that can be configured to trigger the pyrotechnic charge  202  when the pyrotechnic pins  203  receive an activation signal. In some embodiments, the pyrotechnic charge can be connected to another feature that already monitors the flowing current. This other feature, for example, a battery management component, can then be configured to send a signal to activate the pyrotechnic charge when a threshold current level is detected. 
     The pyrotechnic charge  202  can be a single charge structure or a multiple charge structure. In some embodiments, the pyrotechnic charge  202  comprises a double charge structure comprising first an initiator charge and then a secondary gas generator charge. Many different types of pyrotechnic charges can be utilized provided the pyrotechnic charge used is sufficient to provide sufficient force to move the piston structure  204  to permanently break the circuit of the contactor device  100  as described herein. In some embodiments, the pyrotechnic charge  202  comprises zirconium potassium perchlorate, which has the advantage of being suitable for use as both an initiator charge and a gas generator charge. In some embodiments, the initiator charge comprises a fast-burning material such as zirconium potassium perchlorate, zirconium tungsten potassium perchlorate, titanium potassium perchlorate, zirconium hydride potassium perchlorate, or titanium hydride potassium perchlorate. In some embodiments, the gas generator charge comprises a slow-burning material such as boron potassium nitrate, or black powder. 
     When the pyrotechnic charge  202  is activated, the resulting force causes the piston structure  204  to be driven away from its resting position near or around the pyrotechnic charge  202 , which in turn causes the piston structure  204  to push against the shaft  110  and cause the shaft to be driven away from the fixed contacts  104 ,  106 . The resulting force is also sufficient to break or shear off the hard stop  113 , causing the shaft  110  to be forced even further away from the fixed contacts  104 ,  106 , for example, being pushed into a separate internal compartment  206  of the body  102 . The piston structure  204  can comprise sufficient dimensions (e.g. shape, size, spatial orientation or other configuration) such that the piston structure  204  can hold the internal components in a position or configuration wherein electricity cannot flow through the contactor device, for example, by holding the shaft  110  in place further away from the fixed contacts  104 ,  106 , such as, by holding the shaft  110  such that it is substantially within the separate internal compartment  206  of the body  102 . This in turn causes the moveable contact  108 , which is connected to the shaft  110 , to be separated by an even larger spatial gap from the fixed contacts  104 ,  106 , causing the device to be in the “triggered” or permanent “open” configuration wherein electricity cannot flow through the device. In some embodiments, the piston structure  204  comprises sufficient dimensions such that once it is displaced by activation of the pyrotechnic features  202 , the piston structure  204  is forced into a position where it interacts with a portion of the body  102 , such that it cannot easily be moved. 
     In addition to the rapidly created large spatial gap between the fixed contacts  104 ,  106  and the moveable contact  108 , additional structures can be utilized. For example, in some embodiments, one or more arc blowout magnets  208  (two shown) can be utilized to further control electrical arcing. While the main method for interrupting current flow is to rapidly open the contacts to a much larger air gap as described herein, there can also be additional performance gained through a secondary gas blast directed at the arc, for example, through use of a gas generator charge. 
     In some embodiments, including the embodiment shown in  FIG. 1 , other optional design features can be included, which can help prevent hazards caused by the rapid buildup of gas resulting from the activation of the pyrotechnic charge  202 . In these embodiments, the body  102  can be configured such that when the pyrotechnic charge  202  is activated, the piston structure  204  drives the shaft  110  with sufficient force to puncture a portion of the body  102 . This will allow the rapid buildup of gas to escape. This is achieved, in some embodiments, by a portion of the body  102  comprising a membrane that can be punctured during the pyrotechnic disconnect cycle, for example, by a sharp portion  210  of the shaft  110 , allowing gas to escape from a connected vent portion  212  of the body  102 , which can be a high temperature filter membrane. The high temperature gas can then pass out of the body  102 . The pressure release may cool the electrical arc and improve performance as well as prevent the contactor housing from rupturing. 
     The differences between breaking the circuit of electrical flow through the contactor device  100  during normal switching operation and the permanent breaking of the circuit of electrical flow through the contactor device  100  when the device is in its “triggered” state is better illustrated in  FIGS. 2-3 .  FIGS. 2-3  shown the contactor device  100  of  FIG. 1 , but in different orientations. Like in  FIG. 1 ,  FIGS. 2-3  show the body  102 , the fixed contacts  104 ,  106 , the moveable contact  108 , the shaft  110 , the plunger structure  111 , the solenoid  112 , the hard stop  113 , the winged portion  114  of the shaft  110 , the pyrotechnic charge  202 , the pyro pins  203 , the piston structure  204 , the separate compartment  206  of the body  102 , the arc blowout magnets  208 , the sharp portion  210  of the shaft  110 , and the vent portion  212  of the body  102 . 
     The contactor device  100  is shown in its “open” state in  FIG. 2 , which shows the shaft  110  moved such that the connected moveable contact  108  is separated from the fixed contacts  104 ,  106  by a disconnection spatial gap  302 . The contactor device  100 , as shown in  FIG. 2 , is still in the “set” position without the pyrotechnic features being activated. The disconnection spatial gap  302  causes the moveable contact  108  to be spaced a sufficient distance from the fixed contacts  104 ,  106 , which are otherwise electrically isolated from one another, to interrupt flow of electricity through the device. In contrast,  FIG. 3  shows the contactor device  100  in its triggered stated when the pyrotechnic charge  202  has been activated, causing the piston structure  204  to force the shaft  110  and moveable contact  108 , in a direction further away from the fixed contacts  104 ,  106 . This rapidly creates a larger circuit break spatial gap  350  between the fixed contacts  104 ,  106  and the moveable contact  108 . 
     The resulting force from the activation of the pyrotechnic charge  202 , and the resulting sudden movement of the piston structure  204  and the shaft  110 , is sufficient to break or shear off the hard stop  113 , which is shown in  FIG. 3  to be displaced from its original position connected to the body  113 . The hard stop  113  can comprise a sturdy material that is connected or integrated with the body  102 , such that it functions as a stop for the shaft  110  during normal device operation between “closed” and “open” circuit states. However, during operation of the pyrotechnic disconnect features, the hard stop  113  can be intentionally designed to “fail” as a stop structure and break or shear off to allow the shaft  110  to proceed into the separate body compartment  206 . 
     In some embodiments, the piston structure  204  can be configured such that it can interact with a piston-stop portion  352  of the body  102  after the pyrotechnic charge  202  has been activated, for example, by interacting with a position of the piston structure  204 , for example, a portion of the piston-stop portion  352  configured to interact or mate with another portion on the piston structure  204 . 
     In some embodiments, the piston structure  204  will not be in a position to come into contact with the piston-stop portion  352  until after the piston structure  204  has been displaced by activation of the pyrotechnic charge  202 . This causes the piston structure  204  to be held between the piston-stop portion  352  and the moveable contact  108 , when the pyrotechnic charge  202  has been activated and the piston structure  204  has been forced from its resting position. As shown in  FIG. 3 , this configuration places the piston structure  204  in a position which holds or locks the piston structure  204  against the moveable contact  108 . The piston structure  204  holds the moveable contact  108  in place and helps maintain the circuit break spatial gap  350  such that the fixed contacts  104 ,  106  and the moveable contact  108  cannot slip back into contact with each other, rendering the contactor device  100  nonoperational. 
     In some embodiments, in lieu of or in addition to the piston-stop portion  352  of the body  102 , the separate compartment  206  of the body  102 , can comprise sufficient dimensions including, for example, size and shape, such that the separate compartment  206  can interact with a portion of the shaft  110  that has moved into the separate compartment  206  due to activation of the pyrotechnic charge  202 . 
     In some embodiments, the separate compartment can be configured to interact with the sheared off hard stop  113  or another structure connected to the shaft  110  that has moved into the separate compartment  206  due to activation of the pyrotechnic charge  202 . These portions of the shaft  110 , or connected structures, were not previously within the separate compartment  206  during ordinary device operation, but are forced into the separate compartment  206  during the pyrotechnic cycle during overcurrent protection operation. The separate compartment  206  comprise a sufficient size, shape or additional features, for example, features configured to interact or mate with corresponding features on the shaft  110  or connected structure, to hold the shaft  110  in place so the moveable contact  108  connected to the shaft  110  cannot slip back into contact with the fixed contacts  104 ,  106 . 
     In addition to the foregoing features, the contactor device  100  of  FIGS. 1-3  can further comprise a PCB  400 . As will be discussed further herein, the PCB allows for efficient and convenient connection of the internal components of the contactor device  100  to pyrotechnic triggering configurations incorporating features of the present invention. The PCB  400  can be a PCB designed to accommodate pyrotechnic trigging configurations incorporating features of the present invention. In the embodiment shown in  FIGS. 1-3 , the PCB  400  is shown located near the top portion of the contactor device  100 ; however, it is understood that the PCB  400  can be located in or on any portion of the contactor device  100  and can be internal to the contactor device  100  or external to the contactor device  100 . 
     Aside from contactor devices, which can operate to restrict or allow electrical flow through the device during ordinary operation, another type of switching device that can serve as an example environment for use with the passive pyrotechnic triggering configurations are fuse devices. Fuse devices only allow electrical flow through the device during ordinary operation and function as a sacrificial circuit break when a threshold current level passes through the device.  FIGS. 4-5  show such an example fuse device  430 , which comprises similar features, and operates similarly to the contactor device  100 , in  FIGS. 1-3 , however, without comprising some of the features, such as a solenoid or other mechanism for opening and closing the fixed and moveable contacts. During ordinary operation, the fuse device  430  is constantly in a “closed” state allowing current flow through the device, until the pyrotechnic features are activated, resulting in the device being in an “open” state thereafter, preventing current flow through the device.  FIGS. 4-5  show a body  432  (similar to the body  102  in  FIGS. 1-3  above), fixed contacts  434 ,  436  (similar to fixed contacts  104 ,  106  in  FIGS. 1-3  above). However, in this embodiment, the fixed contacts  434 ,  436  are formed separately from the power terminals  438 ,  440 , which are electrically connected to the fixed contacts  434 ,  436  for connection to external circuitry, the power terminals and fixed contacts being one-in-the-same in the embodiment of  FIGS. 1-3 .  FIGS. 4-5  further show moveable contacts  442  (similar to moveable contact  108  in  FIGS. 1-3  above), a shaft structure  444  (similar to the shaft structure  110  in  FIGS. 1-3  above, except shaped differently). 
     The shaft structure  444  is connected to the moveable contact  442  and the piston structure  446  (which is similar to the piston structure  204  in  FIGS. 1-3  above). The piston structure  446  can at least partially surround a pyrotechnic charge  448 , such that when the pyrotechnic charge  448  is activated the moveable contact  442  and the piston structure  446  are forced in a direction away from the fixed contacts  434 ,  436 , therefore breaking the circuits. In some embodiments, the fuse device  430  can comprise a support structure  450  configured to help hold the fixed contacts  434 ,  436  and the moveable contacts  442  in place. In some embodiments, triggering of the pyrotechnic charge  448  causes the piston structure  446  to be driven away from the pyrotechnic charge with such force that the support structure  450  is broken or displaced. In some embodiments, the fuse device  430  can be triggered by active signals. In some embodiments, the fuse device  430  can be triggered by passive triggering configurations, such as those discussed herein.  FIG. 4  shows the fuse device  430  in its “closed” state, wherein the fixed contacts  434 ,  436  and the moveable contacts  442  are together and electrical flow through the device  430  is permitted. In contrast,  FIG. 5  shows the fuse device  430  in its “open” state after triggering of the pyrotechnic charge  448 , wherein the fixed contacts  434 ,  436  and the moveable contacts  444  are separated and electrical flow through the device  430  is prevented. 
     As two types of switching devices, contactors and fuse devices, have been described as example environments that can utilize pyrotechnic triggering mechanisms according to the present disclosure, embodiments of pyrotechnic triggering mechanisms can now be more fully described. In the following embodiments described with regard to  FIGS. 6-11 , the pyrotechnic triggering configurations will be described with reference to being applied to the contactor device of  FIGS. 1-3 . However, it is understood that the pyrotechnic triggering configurations described with regard to  FIGS. 6-11  can be applied as triggering devices in any switching mechanism incorporating pyrotechnic features including, for example, the fuse device described with regard to  FIGS. 4-5 . 
       FIG. 6  shows a pyrotechnic triggering configuration  500  comprising a PCB  502  (traces not shown), similar to PCB  400  in  FIGS. 1-3 , electrical power terminals  504 , similar to the fixed contact structures  104 ,  106  in  FIGS. 1-3 , and a passive trigger switch  506 .  FIG. 6  further shows the pyrotechnic triggering configuration  500  integrated with an electrical device  503 , comprising a body  508 , which can be similar to the body  102 , containing internal components therein. The pyrotechnic triggering configuration  500  in  FIG. 6  is shown without a top “cap” portion of the body so that the PCB  502  is viewable and exposed, however, it is understood that in normal device operation, features such as a closed body including a cap and epoxy material can be included.  FIG. 6  also shows pyrotechnic pins  510 , similar to pyrotechnic pins  203  in  FIGS. 1-3 , coli pins  512 , which allow for electrical connection to an internal coil or solenoid, for example, similar to solenoid  112  in  FIGS. 1-3 , and a tubulation structure  514 , which can facilitate formation of an internal hermetic seal or management of electronegative gases within the electrical device  503 . 
     In operation of the pyrotechnic triggering configuration  500  of  FIG. 6 , when a pre-determined level of current passes through the device  503 , for example, a level of current denoting a dangerous level of current that can result in permanent damage to a device or creation of a hazard such as a fire, the passive trigger switch  506  will activate and complete a circuit to transmit a signal to the pyrotechnic pins  510 , thereby activating an internal pyrotechnic element, for example, such as pyrotechnic charge  202  in  FIGS. 1-3 . In these embodiments, the PCB  502  can be configured such that it directs a triggering signal to the pyrotechnic pins  510 , which are in electrical communication with pyrotechnic features internal to the device  503 . The electrical pathway for this triggering signal can be dependent on closing or activating the passive trigger switch  506 , such that when the passive trigger switch  506  is open or un-triggered (in a resting state) the electrical pathway for the triggering signal to the pyrotechnic pins  510  is obstructed. Likewise, when the passive trigger switch  506  is closed or activated, the triggering signal can be directed toward the pyrotechnic pins  510  and trigger the internal pyrotechnic feature. 
     The passive trigger switch  506  can be connected to a sensor that is configured to detect when a predetermined level of current passes through the device  503 , the sensor signals the passive trigger switch  506  to trigger. In some embodiments, it is the passive trigger switch  506  itself that is configured detect or passively respond and trigger when the current flowing through the device  503  reaches a pre-determined level. For example, in some embodiments, the passive trigger switch  506  comprises a switch configured to react to a magnetic field generated by current flowing through the electrical power terminals  504  of the device  503  or from the flow of current through a region of the device  503 . 
     In some embodiments, the passive trigger switch  506  is a reed switch or other switching mechanism configured to activate in response to the generation of a magnetic field of sufficient strength. Different configurations can be utilized with a reed switch. For example, the reed switch can be configured such that the contacts are open when resting, closing when a sufficient magnetic field is present, or closed when resting, opening when a sufficient magnetic field is present. Furthermore, in some embodiments, the reed switch can be organized into a reed relay and be actuated by a magnetic coil. In most embodiments incorporating a reed switch herein, the reed switch is configured such that the contacts are open when resting, preventing an electrical signal from traveling to the pyrotechnic pins  510  and activating the pyrotechnic features until a sufficient magnetic field corresponding to a dangerous current level closes the reed switch. 
     In some of the embodiments, the PCB  502  comprises a plurality of passive trigger switch mounting features  516 , which allow the pyrotechnic triggering configuration  500  to be adjusted according to desired trip current. For example,  FIG. 7  shows the pyrotechnic triggering configuration  500 , PCB  502 , the electrical device  503 , the electrical power terminals  504 , the passive trigger switch  506 , the body  508 , the pyrotechnic pins  510 , the coil pins  512 , the tubulation structure  514 , and the trigger switch mounting features  516 . As shown in  FIG. 7 , the desired trip current can be adjusted by mounting the passive trigger switch  506  to a different one of the trigger switch mounting features  516 , which in turn adjusts the trip distance  518  between the passive trigger switch  506  and one or more of the electrical power terminals  504 . 
     By adjusting the trip distance  518  between the passive trigger switch  506  and one or more of the power terminals  504 , the amount of current flowing through the device  503  that is required to activate the passive trigger switch  506 , and therefore trigger the device&#39;s internal pyrotechnic features, can be adjusted. For example, the passive trigger switch  506  can comprise a reed switch that is configured to activate when a pre-determined magnetic field is generated due to a pre-determined level of current flowing through the power terminals  504 . The strength of the magnetic field needed to trigger the passive trigger switch  506 , and therefore the level of corresponding current flowing through the device required to trigger the passive trigger switch  506 , can be adjusted by simply changing the trip distance  518  between the passive trigger switch  506  and the power terminals  504 , for example, by mounting the passive trigger switch  506  to a different passive trigger switch mounting feature  516 . 
     By moving the passive trigger switch  506  farther from the power terminal  504 , a greater magnetic field, and therefore a greater current, would be required to trigger the passive trigger switch  506  and therefore trigger the pyrotechnic features of the device  503 . This can provide a pre-designed switching device with a pre-designed PCB so that the device can be mass manufactured, while allowing for different trip currents based upon placement of the passive trigger switch  506  at a different one of the passive trigger switch mounting features  516 . For example, the passive trigger switch mounting features  516  can be on locations of the PCB  502  corresponding to different levels of magnetic field strength, which in turn can correspond to different levels of desired trip current. A company can manufacture one PCB configuration and can place the passive trigger switch  506  at different passive trigger switch mounting features  516  to create devices that will trip at different currents. In embodiments utilizing a coil or solenoid, for example as with contactors, the passive trigger switch  506  can be configured to turn off power to the coil. In these embodiments, this configuration can decrease the time it takes for the pyrotechnic features to open the contacts as it will not have to resist the coil. 
     In other embodiments, additional features can be included in lieu of, or in addition to, the trigger switch mounting features  516  in order to further interact with the passive trigger switch  506 . For example,  FIG. 8  shows a pyrotechnic triggering configuration  600  (similar to pyrotechnic triggering configuration  500  in  FIG. 7 ), a PCB  602  (similar to the PCB  502  in  FIG. 7 ), an electrical device  603  (similar to the electrical device  503  in  FIG. 7 ), electrical power terminals  604  (similar to electrical power terminals  504  in  FIG. 7 ), a passive trigger switch  606  (similar to the passive trigger switch  506  in  FIG. 7 ), a body  608  (similar to the body  508  in  FIG. 7 ), pyrotechnic pins  610  (similar to the pyrotechnic pins  510  in  FIG. 7 ), coil pins  612  (similar to coil pins  512  in  FIG. 7 ), and a tubulation structure  614  (similar to the tubulation structure  514  in  FIG. 7 ). Although similar embodiments could include trigger switch mounting features, the embodiment shown in  FIG. 8  does not include trigger switch mounting features. Instead, the pyrotechnic triggering configuration  600  includes a core structure  630  that contributes to determining the targeted trip current of the pyrotechnic triggering configuration  600 . 
     The core structure  630  can comprise any known material that can channel, direct, or control a magnetic field generated by current flowing through the device  603 . For example, in some embodiments, the core structure  630  comprises metal. In some embodiments, the core structure  630  comprises iron, a ferrous alloy or another ferrous material. In some embodiments, the core structure  630  is magnetic. The core structure  630  can comprise any suitable shape or configuration that produces the desired magnetic field characteristics, including any regular or irregular polygon or a custom shape. In the embodiment shown in  FIG. 8 , the core structure  630  comprises a curved strip-shape. The core structure  630  can be configured in any spatial position in relation to the device  603  and the PCB  602  to facilitate interaction between a generated magnetic field and the passive trigger switch  606 . In the embodiment shown in  FIG. 8 , the core structure  630  at least partially surrounds one of the electrical power terminals  604  and is adjacent to the passive trigger switch  606 . 
     As the magnetic field generated from the core structure  630  is more significant than that of the power terminal itself, the desired trigger current can be controlled by adjusting the distance between a portion of the core structure  630  and the passive trigger switch  606 , rather than from the power terminal  604  and the passive trigger switch  606  as in the embodiment of  FIGS. 6-7 . For example,  FIG. 9  shows the pyrotechnic triggering configuration  600 , the PCB  602 , the electrical device  603 , the electrical power terminals  604 , the passive trigger switch  606 , the body  608 , the pyrotechnic pins  610 , the coil pins  612 , the tubulation structure  614 , and the core structure  630 .  FIG. 9  further shows the trip distance  636  between the passive trigger switch  606  and the core structure  630 . Like with the embodiment of  FIGS. 7-8 , the passive trigger switch  606  can comprise a reed switch, or other passive mechanism, that is configured to activate when a pre-determined magnetic field is generated due to a pre-determined level of current flowing through the power terminal  604  and/or the core structure  630 . 
     The strength of the magnetic field needed to trigger the passive trigger switch  606 , and therefore the level of corresponding current flowing through the device required to trigger the passive trigger switch  606 , can be adjusted by simply changing the trip distance  636  between the passive trigger switch  606  and a portion of the core structure  630 . By moving the passive trigger switch  606  farther from the core structure  630 , a greater magnetic field, and therefore a greater current, would be required to trigger the passive trigger switch  606  and therefore trigger the pyrotechnic features of the device  603 . 
     In some embodiments, in lieu of or in addition to trigger switch mounting features  606  or a core structure  630 , an external triggering mechanism can be utilized. In some embodiments, this external triggering mechanism can replace the need for a PCB, although in other embodiments, the external triggering mechanism can be utilized in addition to a PCB. An example embodiment, wherein an external triggering mechanism replaces the need for a PCB is shown in  FIG. 10 .  FIG. 10  shows a pyrotechnic triggering configuration  700  (similar to pyrotechnic triggering configuration  600  in  FIG. 8 ), an electrical device  703  (similar to the electrical device  603  in  FIG. 8 ), electrical power terminals  704  (similar to electrical power terminals  604  in  FIG. 8 ), a passive trigger switch  706  (similar to the passive trigger switch  606  in  FIG. 8 ), a body  708  (similar to the body  608  in  FIG. 8 ), pyrotechnic pins  710  (similar to the pyrotechnic pins  610  in  FIG. 8 ), access points  712 , which can provide wire access to an internal solenoid or coil, and a tubulation structure  714  (similar to the tubulation structure  614  in  FIG. 8 ).  FIG. 10  also shows the body  708  comprising a top or cap portion  716 , through which the power terminals  704  protrude. 
     It is understood that a similar top or cap portion to the cap portion  716  of the body  708  shown in  FIG. 10  can be applied to all other embodiments incorporating features of the present invention. For example, it is understood that the device embodiments of  FIG. 6  and  FIG. 8  are shown without a cap portion in order to better illustrate the underlying PCB configurations. However, during final assembly, the embodiments of  FIG. 6  and  FIG. 8  can have all internal components completely enclosed within the body and comprise a cap portion of the body. 
     The embodiment of  FIG. 10  further shows an external triggering mechanism  730 , which comprises the passive trigger switch  706 , a conductive bus bar  732 , and a spacer portion  734 . As is shown in  FIG. 10 , the conductive bus bar  732  can comprise multiple connection portions, with the conductive bus bar  732  in the embodiment shown comprising a first connection point  736 , which is configured to connect to the device  708  at least one of the power terminals  704  and a second connection point  738  configured to connect to an outside power source. 
     The conductive bus bar  732  can comprise any conductive material, for example, a metallic material. In some embodiments, the conductive bus bar  732  comprises copper. The spacer portion  734  can comprise a non-magnetic material. The conductive bus bar  732  can be configured to allow current to flow to the pyrotechnic pins  710  and therefore to trigger the internal pyrotechnic features of the device  703 . The passive trigger switch  706 , similar to the passive trigger switches in the embodiments of  FIGS. 6 and 8 , is configured in an open state, that does not allow electrical current to pass though the conductive bus bar  732  and therefore to allow triggering of the pyrotechnic features. 
     When the current from the device  703  reaches a threshold level, a sufficient magnetic field is generated to trigger the passive trigger switch  706 , which allows current from the external power source connected to the second connection  738  of the conductive bus bar  732  to flow through the conductive bus bar  732  to the pyrotechnic pins  710  and therefore trigger the pyrotechnic features of the device. 
     The threshold magnetic field needed to activate the passive trigger switch  706 , and therefore the necessary current level defined as sufficiently dangerous to warrant activating the pyrotechnic circuit-breaking features, can be adjusted by adjusting the distance of the passive trigger switch  706  from the conductive bus bar  732 ; this can be achieved, for example, by adjusting the thickness of the non-magnetic spacer portion  734 . For example,  FIG. 11  shows a close-up sectional view of the external triggering mechanism  730  of  FIG. 10 , including the passive trigger switch  706 , the conductive bus bar  732 , and the spacer portion  734 , the first connection point  736 , and the second connection point  738 .  FIG. 11  also shows the trip distance  750 , which corresponded to the thickness of the non-magnetic spacer portion  734 . 
     Like with the embodiments discussed above, the passive trigger switch  706  can comprise a reed switch, or other passive mechanism, that is configured to activate when a pre-determined magnetic field is generated due to a pre-determined level of current flowing through the power terminal  604 , in this case, the power terminal  604  that is in electrical connection with the external triggering mechanism  730 . The strength of the magnetic field needed to trigger the passive trigger switch  706 , and therefore the level of corresponding current flowing through the device  703  required to trigger the passive trigger switch  706 , can be adjusted by simply changing the trip distance  750  between the passive trigger switch  706  and the conductive bus structure  732 . By increasing the thickness of the non-magnetic spacer portion  734 , and therefore moving the passive trigger switch  706  farther from the conductive bus structure  732 , a greater magnetic field, and therefore a greater current, would be required to trigger the passive trigger switch  706  and therefore trigger the pyrotechnic features of the device  703 . Likewise, by moving the passive trigger switch  706  closer to the conductive bus structure  732 , a lesser magnetic field, and therefore lesser current, would be required to trigger the passive trigger switch  706  and therefore trigger the pyrotechnic features of the device  703 . 
     Although the present invention has been described in detail with reference to certain preferred configurations thereof, other versions are possible. Embodiments of the present invention can comprise any combination of compatible features shown in the various figures, and these embodiments should not be limited to those expressly illustrated and discussed. Therefore, the spirit and scope of the invention should not be limited to the versions described above. 
     The foregoing is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention, wherein no portion of the disclosure is intended, expressly or implicitly, to be dedicated to the public domain if not set forth in any claims.