Passive trigger mechanisms for use with switching devices incorporating pyrotechnic elements

Abstract

The present invention relates to passive trigger mechanisms for activating pyrotechnic elements within electrical switching devices, such as contactor devices and fuse devices. Activation of the pyrotechnic elements is intended to change the configuration of the internal components of the switching device and prevent current from flowing through the device. In some embodiments, the trigger mechanisms include elements that respond to a magnetic field, such as a reed switch. In some embodiments, the reed switch responds to the flow of a high current and may then use the signal from the high current flow to activate the pyrotechnic element. In other embodiments, the reed switch uses a signal from a secondary power source to activate the pyrotechnic element. Figure for abstract: Fig.6.

Description

Title of the invention: Passive trigger mechanisms for use with switching devices incorporating pyrotechnic elements Technical field

[0001] The present invention relates to devices relating to tripping mechanisms and configurations for use with electrical switching devices, such as contactor devices and electrical fuse devices. Presentation of the invention

[0002] Connecting or disconnecting an electrical circuit is a concept as old as electrical circuits themselves, and is often used as a method for switching power to a connected electrical device between an "on" state and an "off" state. An example of a device commonly used to connect and disconnect a circuit is a contactor, which is electrically connected to one or more devices or power sources. A contactor is configured so that it can interrupt or complete a circuit in order to control electrical power flowing to or from a device. A common type of contactor is the hermetic contactor.

[0003] In addition to contactors, which are used to connect and disconnect electrical circuits during normal operation of a device, various additional devices may be employed to provide overcurrent protection. These devices can prevent short circuits, overloads, and irreversible damage to an electrical system or a connected electrical device. These devices include disconnecting devices that can quickly and permanently break the circuit so that the circuit will remain broken until the disconnecting device is repaired, replaced, or reset. One such disconnecting device is a fuse. A conventional fuse is a type of low-impedance resistor that acts as a sacrificial device.A typical fuse consists of a wire or metal strip that melts when too much current flows through it, interrupting the circuit it connects.

[0004] As society evolves, various innovations in electrical systems and electronic devices are becoming increasingly commonplace. An example of these innovations includes recent advances in electric cars, which are likely to one day become the energy-efficient standard and replace traditional gasoline-powered vehicles. In such devices In the context of regularly used and expensive electrical devices, overcurrent protection is particularly applicable to prevent device malfunctions and prevent irreversible damage to devices. In addition, overcurrent protection can prevent the risk of accidents, such as electrical fires. These modern improvements in electrical systems and devices require modern solutions to increase the convenience and efficiency of fuse device tripping mechanisms. Summary of the invention

[0005] The present invention relates to passive triggering elements and configurations for activating pyrotechnic elements intended to function as a fuse mechanism within switching devices such as contactors or fusible devices. These passive triggering configurations may be configured to trigger in response to a threshold intensity of a magnetic field, corresponding to a threshold current level flowing through the device that corresponds to a dangerous overcurrent. The threshold current level necessary to trigger these passive triggering configurations may 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 an element connected to a power terminal.

[0006] One embodiment of an electrical switching device according to the present invention includes a housing having internal components configured to change the state of the switching device from a closed state that allows current to flow through the switching device to an open state that interrupts the flow of current through the switching device. A pyrotechnic element is included that is configured to interact with the internal components to change the switching device from the closed state to the open state when the pyrotechnic elements are activated. A passive trigger switch structure is also included that is configured to activate the pyrotechnic elements when triggered, the passive trigger switch structure being configured to trigger in response to a high current signal flowing through the switching device.The passive trigger switch is also intended to use the high current signal to activate the pyrotechnic element.

[0007] One embodiment of an electrical system according to the present invention includes a utility power circuit including a utility power source coupled to a utility load by a current path, with a contactor between the power source and the load. A pyrotechnic activation circuit is included, comprising a trigger adapted to detect a high current in the service supply circuit, the activation circuit further comprising a pyrotechnic actuator, the trigger activating said pyrotechnic actuator to act on the contactor to interrupt the current path in the service supply circuit.

[0008] One embodiment of a pyrotechnic activation circuit according to the present invention includes a trigger adapted to detect the magnetic field emanating from a high current in a circuit. A pyrotechnic actuator is included, the trigger activating the pyrotechnic actuator in response to the high current level to interrupt the circuit carrying the high current, wherein the trigger uses the high current to activate the pyrotechnic actuator.

[0009] The above-mentioned features and advantages of the invention, and others still, will become more clearly apparent to those skilled in the art upon reading the following detailed description, taken in conjunction with that of the accompanying drawings, in which the same reference numerals designate corresponding parts in FIG., and in which: Brief description of the drawings

[0010] [Fig. 1] is a front sectional view of one embodiment of a contactor that may incorporate elements of the present invention, shown in the "closed" orientation that allows electricity to flow through the device;

[0011] [Fig.2] is a front sectional view of the embodiment of the contactor device of [Fig.l], shown in an "open" or "disconnected" orientation which prevents electricity from flowing through the device;

[0012] [Fig.3] is a front sectional view of the embodiment of the contactor device of [Fig.l], shown in a different orientation in which the disconnecting elements have been “triggered”;

[0013] [Fig.4] is a front sectional view of a fuse device capable of incorporating elements of the present invention, shown in the “unfired” resting state;

[0014] [Fig.5] is a front sectional view of a fuse device capable of incorporating elements of the present invention, shown in the activated "triggered" state;

[0015] [Fig.6] is a front and top perspective view of a configuration of pyrotechnic trigger incorporating features of the present invention;

[0016] [Fig.7] is a rear and top view of the trigger configuration pyrotechnic of [Fig.6];

[0017] [Fig.8] is a front and top perspective view of another configuration of pyrotechnic trigger incorporating features of the present invention;

[0018] [Fig.9] is a rear and top view of the pyrotechnic trigger configuration of [Fig.8];

[0019] [Fig. 10] is a front and top perspective view of yet another pyrotechnic trigger configuration incorporating features of the present invention;

[0020] [Fig. 11] is a front sectional view of a portion of the pyrotechnic trigger configuration of [Fig. 10];

[0021] [Fig. 12] is a diagram of an embodiment of a pyrotechnic power supply switching circuit according to the present invention; and

[0022] [Fig. 13] is a diagram of another embodiment of a pyrotechnic power supply switching circuit according to the present invention. Detailed description

[0023] Various embodiments of the present invention are now detailed in the following description. These embodiments present passive triggering elements and configurations for use with switching devices, such as contactors or fusible devices, incorporating pyrotechnic circuit breaker elements. These switching devices may be electrically connected to an electrical device or system to turn the connected device or system "on" or "off." Although the example devices described herein may use active triggering configurations in addition to, or instead of, the passive elements described, the passive elements provide the advantage of automatically triggering a pyrotechnic circuit break in response to a threshold current level.

[0024] In some embodiments, a printed circuit board (PCB) or an external trigger mechanism is configured to send a signal to pyrotechnic pins in communication with a pyrotechnic charge. The power for this signal to trigger the pyrotechnic elements of the switching device may 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). Alternatively, the signal power may 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 operate as a fuse, permanently breaking the circuit through the contactor or fuse device, for example, by putting moving contacts out of contact with fixed contacts.

[0025] The printed circuit board or external trigger mechanism incorporates a passive trigger switch, such as a reed switch, which is open in its resting state, preventing the trigger signal from being sent to the pyrotechnic pins and therefore allowing current to flow through the device. The passive trigger switch may be configured to trigger in response to a magnetic field of sufficient strength, which may be calculated to correspond to a desired threshold current level through the device, for example, a dangerous overcurrent. Because the threshold magnetic field strength necessary 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 may be configured as a "proximity switch."This allows the desired trigger current to be set based on the distance between the passive trigger switch and a region of the device, such as one of the power terminals.

[0026] In other embodiments, additional features may be included. For example, a ferrous core structure may be provided to at least partially surround one of the power terminals of the switching device and the trip current may be determined by the distance between the core structure and the passive trip switch. In some embodiments, external trip mechanisms may be used, which may incorporate a conductive bus portion and a passive trip switch spaced from the conductive bus portion by a non-magnetic spacer portion. In these embodiments, the trip current may be determined by the thickness of the non-magnetic spacer portion.

[0027] Throughout this specification, the preferred embodiment and illustrated examples are to be considered as representations, and not as limitations of the present invention. As used herein, the term "invention," "device," "present invention," or "present device" refers to any of the embodiments of the invention described herein, and to possible equivalents. Furthermore, the fact that one or more various features of the "invention," the "device," the "present invention," or the "present device" are recited throughout this document does not imply that all claimed embodiments or methods must include the recited feature(s).

[0028] It is also understood that where an element or feature is indicated as being “on” or “beside” another element or feature, the element or feature may be directly on or beside the other element or feature, or intervening elements or features may also be be present. It is also understood that when an element is indicated as being “attached,” “connected,” or “coupled” to another element, it may be directly attached, connected, or coupled to the other element, or intermediate elements may be present. Conversely, when an element is indicated as being “directly attached,” “directly connected,” or “directly coupled” to another element, no intermediate elements are present.

[0029] Relative terms, such as "external", "above", "lower", "below", "horizontal", "vertical" and similar terms may be used herein to describe a relationship between one feature and another. It is understood that these terms are intended to encompass different orientations in addition to the orientation shown in FIGS.

[0030] Although the terms first, second, etc. may be used herein to describe various elements or components, such elements or components should not be limited by these terms. These terms are used solely to distinguish one element or component from another element or component. Thus, a first element or component described herein could be referred to as a second element or component without departing from the teachings of the present invention.

[0031] The terminology used herein is solely for the purpose of describing particular embodiments and is not intended to limit 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 "includes," "comprising," when used herein, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] Embodiments of the invention are described herein with reference to various views and illustrations which are schematic illustrations of idealized embodiments of the invention. As such, variations from the shapes of the illustrations resulting, for example, from manufacturing techniques and / or tolerances are to be expected. Embodiments of the invention should not be considered as being limited to the particular shapes of the regions illustrated herein, but should include deviations in shape which result, for example, from manufacturing.

[0033] It is understood that when a first element is said to be “between”, “sandwiched”, or “sandwiched between” two or more other elements, the first element may be directly between the two or more other elements, or intermediate elements may also be present between the two or more other elements. or more other elements. For example, if a first element is "between" or "sandwiched between" a second and third element, the first element may be directly between the second and third elements with no intervening elements, or the first element may be adjacent to one or more additional elements, with the first element and those additional elements all being between the second and third elements.

[0034] Before describing in detail specific pyrotechnic triggering configurations incorporating elements of the present invention, examples of switching devices incorporating pyrotechnic elements and providing example environments for passive triggering configurations according to the present invention are described. These switching devices may include any switching devices incorporating pyrotechnic elements, for example, contactors configured to allow switching of a device between an "active" state and an "inactive" state.

[0035] In some contactor devices, the pyrotechnic elements function as an integrated fuse element throughout the contactor device. Examples of such contactor devices are disclosed in U.S. Application No. 16 / 101,143, entitled Contacter Device Integrating Pyrotechnic Disconnect Features, which has been assigned to Gigavac, the assignee of the present application. In addition to contactors configured to be freely switched between "on" and "off" states, pyrotechnic trigger configurations according to the present invention may also be used with sacrificial fuse devices that are configured to allow current to flow through an electrical system or device when not triggered, and to prevent current from flowing through the electrical system or device when triggered.Examples of such fusible devices are presented in US Application No. 15 / 889,516, entitled MECHANICAE FUSE DEVICE (mechanical fusible device), which has been assigned to Gigavac, assignee hereof.

[0036] To cite an example of a contactor device incorporating pyrotechnic elements, [Fig. 1] shows a cross-sectional view of an exemplary embodiment of a contactor device 100, which includes an integrated pyrotechnic disconnect component that can function as a sacrificial disconnect element in the event of an overcurrent. [Fig. 1] shows the contactor device 100 in a “closed” circuit position, in which the flow of electricity through the contactor device is enabled. [Fig. 1] further shows the pyrotechnic disconnect portion of the contactor device 100 in its un-tripped or “armed” mechanical orientation, allowing the contactor device to operate normally to operate between its "closed" and "open" position. The disconnect portion of the contactor device 100 also has a "tripped" 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" modes of the contactor as well as the "armed" and "tripped" disconnect modes are described in more detail later in this document.

[0037] The contactor device 100 of [Fig. 1] includes a body 102 (also referred to as housing 102), and two or more fixed contact structures 104, 106 (two shown) that are configured to electrically connect the internal components of the contactor device to an external circuit, for example, to an electrical system or device. The body 102 may include any material suitable for supporting the structure and functionality of the contactor device 100 as described herein, with a preferred material being a solid material capable of providing structural support to the contactor device 100 without impeding 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 material.The body 102 at least partially surrounds the various internal components of the contactor device 100, which are described in more detail later in this document.

[0038] The body 102 may comprise any shape suitable for housing the various internal components, and including any regular or irregular polygon. The body 102 may be a continuous structure, or may comprise several assembled component parts, for example, comprising a base "cup" body and an upper "manifold" portion sealed with an epoxy-based material. Some examples of body configurations include those shown in U.S. Patent Nos. 7,321,281, 7,944,333, 8,446,240, and 9,013,254, all of which have been assigned to Gigavac, the assignee of this application.

[0039] The fixed contacts 104, 106 are configured so 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 explained herein. The fixed contacts 104, 106 may comprise any conductive material for providing electrical contact to the internal components of the contactor device, e.g., various metals and metallic materials or any electrical contact material or structure known in the art. The fixed contacts 104, 106 may comprise simple continuous contact structures (as shown) or may include multiple electrically connected structures. For example, in some embodiments, the fixed contacts 104, 106 may include 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 explained herein.

[0040] The body 102 may 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. Combined with the use of an electronegative gas, this hermetically sealed configuration may help mitigate or prevent the formation of an electrical arc between two adjacent conductive elements, and in some embodiments, helps provide electrical isolation between spatially separated contacts. In some embodiments, the body 102 may be subjected to vacuum conditions. The body 102 may be hermetically sealed using any known means for producing hermetic electrical devices. Some examples of hermetic devices include those disclosed in U.S. Patent Nos. 7,321,281, 7,944,333, 8,446,240, and 9,013,254, all of which have been assigned to Gigavac, the assignee of this application.

[0041] In some embodiments, the body 102 may be at least partially filled with an electronegative gas, e.g., sulfur hexafluoride or a 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 may comprise various gases, liquids, or solids configured to enhance the performance of the device.

[0042] Before describing the pyrotechnic disconnecting components of the contactor device 100 used for overcurrent protection, the contactor components used in ordinary switching use of the contactor device 100 are described. When not interacting with any of the other components internal to the body 102, the stationary contacts 104, 106 are otherwise electrically isolated from one another such that electricity cannot flow freely between them. The stationary contacts 104, 106 may be electrically isolated from one another through any known electrical insulation structure or method.

[0043] When the contactor device 100 is in its "closed" position, as shown in [Fig.l], the two otherwise electrically isolated fixed contacts 104, 106 are brought into contact with a movable contact 108. The movable 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 movable 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 movable contact is in electrical contact with the fixed contacts.

[0044] The movable contact 108 may comprise any suitable conductive material, including any of the materials discussed herein with respect to the fixed contacts 104, 106. As with the fixed contacts 104, 106, the movable contact 108 may comprise a simple continuous structure (as shown), or may comprise several component parts electrically connected to each other so as to serve as a contact bridge between the otherwise electrically isolated fixed contacts 104, 106, so that electricity may flow through the contactor device 100.

[0045] The movable contact 108 may be configured to be electrically contactable with or out of contact with the fixed contacts 104, 106. This causes the circuit to be "closed" or completed when the movable contact is in electrical contact with the fixed contacts 104, 106, and to be "opened" or broken when the movable contact 108 is not in electrical contact with the fixed contacts 104, 106. The fixed contacts 104, 106 are otherwise electrically isolated from each other when not in contact with the movable contact 108. In some embodiments, including the embodiment shown in [Fig. 1], the movable contact 108 is physically connected to a shaft structure 110, which is configured to move a predetermined distance within the contactor device 100.The shaft 110 may comprise any material or have any shape suitable for its function as an internal movable component that is physically connected to the movable contact 108, such that the movable contact 108 can move with the shaft 110.

[0046] Movement of the shaft 110 controls movement of the movable contact 108, which in turn controls the position of the movable contact 108 relative to the fixed contacts 104, 106, which in turn control the flow of electricity through the contactor device 100 described herein. Movement of the shaft may be controlled through various configurations, including, but not limited to, electrical and electronic, magnetic and solenoid, and manual. Examples of manual configurations for controlling a shaft connected to a movable contact are shown in U.S. Patent No. 9,013,254 to Gigavac, the assignee of this application. Some of these examples of manual control element configurations include magnetic configurations, membrane configurations, and bellows configurations.

[0047] In the embodiment shown in [Fig.l], the movement of the shaft 110 is controlled via the use of a solenoid configuration. A structure of pusher 111 is connected to a portion of the shaft 110, or at least partially surrounds it. The body 102 also houses a solenoid 112. Many different solenoids may be used, an example of a suitable solenoid being one that operates at low voltage and with relatively high force. An example of a suitable solenoid is the commercially available solenoid model No. SD1564 N1200 from Bicron, but many other solenoids may be used. In the illustrated embodiment, the pusher structure 111 may comprise a metallic material that can be moved and controlled by the solenoid 112. Movement of the pusher structure 111 controls movement of the connected shaft 110, which in turn controls movement of the connected movable contact 108.

[0048] The travel of the shaft 110 may be controlled using various elements, for example, springs to control the travel or overtravel, or various parts of the body 102 that may block or limit the travel of the shaft 110. In the embodiment shown in [Fig.l], the travel of the shaft 110 is partially controlled by a rigid stop 113, which is configured to abut 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 rigid stop 113 may comprise any material or have any shape suitable for providing a surface for it to interact with the shaft 110 to limit the movement or travel of the shaft 110. In the embodiment shown in [Fig.l], the stop rigid 113 comprises a plastic material.In some embodiments, the rigid stop 113 is configured to break or tear when the pyrotechnic disconnect elements are triggered, as explained in more detail below.

[0049] Now that the basic switching elements of the contactor device 110 have been presented, the pyrotechnic disconnecting elements are described. The contactor device 100 may include several elements that can serve as overcurrent protection, including a pyrotechnic charge 202 and a piston structure 204. The piston structure 204 may be located proximate to or at least partially around one or more of the internal components, for example, the shaft 110 shown. Movement of the piston from a rest position may change the configuration of the internal components to interrupt the flow of electricity through the device, for example, by pushing against the shaft 100 described herein, or by moving it in some other manner.The pyrotechnic charge 202 may be configured to activate when the current exceeds a predetermined threshold level, to prevent a connected electrical device from suffering irreversible damage or the risk of an accident such as an electrical fire.

[0050] The contactor device 100 may include various sensor elements that can detect when a current flowing 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 may include a special current sensor, configured to detect the level of current flowing through the device. The current sensor may be configured to directly or indirectly activate the pyrotechnic charge when the current has reached a threshold level. In some embodiments, the current sensors may output 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 may include a Hall effect sensor, a transformer or current clamp, a resistor, a fiber optic current sensor, or an interferometer.

[0051] In some embodiments, the pyrotechnic charge 202 is configured to be activated by an electrical pulse and is driven by an inflatable air bag system configured to detect multiple factors, similar to that used in current vehicles. In some embodiments, the contactor device 100 may include one or more pyrotechnic prongs 203 that may be configured to trigger the pyrotechnic charge 202 when the pyrotechnic prongs 203 receive an activation signal. In some embodiments, the pyrotechnic charge may be connected to another element that already monitors the current flow. This other element, for example, a battery management component, may then be configured to send a signal to activate the pyrotechnic charge when a threshold current level is detected.

[0052] The pyrotechnic charge 202 may be a single-charge structure or a multi-charge structure. In some embodiments, the pyrotechnic charge 202 comprises a dual-charge structure comprising first an initiating charge and then a secondary gas-generating charge. Many different types of pyrotechnic charges may be used, provided that 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 described herein. In some embodiments, the pyrotechnic charge 202 comprises zirconium / potassium perchlorate, which has the advantage of being usable as both an initiating charge and a gas-generating 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-generating charge comprises a slow-burning material such as potassium boron nitrate, or black powder.

[0053] When the pyrotechnic charge 202 is activated, the resulting force causes the piston structure 204 to be driven away from its rest 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 tear the rigid stop 113, causing the shaft 110 to be pushed even further away from the fixed contacts 104, 106, for example, by being pushed into a separate internal compartment 206 of the body 102. The piston structure 204 may include sufficient dimensions (shape, size, spatial orientation, or other configuration) so that the piston structure 204 can maintain the internal components in a position or configuration in which electricity cannot flow through the contactor device.This is achieved, for example, by holding the shaft 110 in place even further from the fixed contacts 104, 106, such as by holding the shaft 110 so that it is substantially within the separate internal compartment 206 of the body 102. This then causes the movable contact 108, which is connected to the shaft 110, to be separated by an even wider spatial interval from the fixed contacts 104, 106, thereby causing the device to be in the permanent "triggered" or "open" configuration in which electricity cannot flow through the device. In some embodiments, the piston structure 204 includes sufficient dimensions so that once moved by activation of the pyrotechnic elements 202, the piston structure 204 is pushed into a position where it interacts with a portion of the body 102, such that it cannot be readily moved.

[0054] In addition to the large spatial gap rapidly created between the fixed contacts 104, 106 and the movable contact 108, additional structures may be used. For example, in some embodiments, one or more arc-blowing magnets 208 (two shown) may be used to further limit arcing. Although the primary method for interrupting current flow is to rapidly open the contacts to achieve a much wider air gap as described herein, it is also possible to achieve a performance gain via a secondary gas jet directed at the arc, for example via a gas-generating charge.

[0055] In some embodiments, including the embodiment shown in [Fig.l], it is possible to include other optional design elements, which may help to prevent hazards caused by the rapid accumulation of gas resulting from the activation of the pyrotechnic charge 202. In these embodiments, the body 102 may be configured so that when the charge pyrotechnic disconnect cycle 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 may be a high-temperature filter membrane. The high-temperature gas can then exit the body 102. The expansion can then cool the electric arc and improve performance as well as prevent the contactor housing from rupturing.

[0056] The differences between breaking the electrical current circuit through the contactor device 100 during a normal switching operation and permanently breaking the electrical current circuit through the contactor device 100 when the device is in its "tripped" state are best illustrated in [Fig. 2] and 3. [Fig. 2] and 3 show the contactor device 100 of [Fig. 1], but in different orientations. The contactor device 100 comprises a body 102, fixed contacts 104, 106, a movable contact 108, a shaft 110, a pusher structure 111, a solenoid 112, a rigid stop 113, a winged portion 114 of the shaft 110, a pyrotechnic charge 202, pyrotechnic pins 203, a piston structure 204, a separate compartment 206 of the body 102, arc blowing magnets 208, a cutting portion 210 of the shaft 110, and the vent portion 212 of the body 102.

[0057] The contactor device 100 is shown in its "open" state in [Fig. 2], which shows the shaft 110 moved so that the connected movable contact 108 is separated from the fixed contacts 104, 106 by a disconnecting spatial gap 302. The contactor device 100, as shown in [Fig. 2], is always in the "armed" position without the pyrotechnic elements being activated. The disconnecting spatial gap 302 causes the movable contact 108 to be spaced a sufficient distance from the fixed contacts 104, 106, which are otherwise electrically isolated from each other, to interrupt the flow of electricity through the device. Conversely, [Fig. 3] shows the contactor device 100 in its triggered state when the pyrotechnic charge 202 has been activated, causing the piston structure 204 to push the shaft 110 and the movable contact 108, in a direction even further away from the fixed contacts 104, 106.This quickly creates a wider circuit-breaker spatial gap 350 between the fixed contacts 104, 106 and the movable contact 108.

[0058] The force caused by the activation of the pyrotechnic charge 202, and the resulting sudden displacement of the piston structure 204 and shaft 110, are sufficient to cut or tear the rigid stop 113, which is shown in [Fig. 3] as being displaced from its initial position connected to the body 113. The Rigid stop 113 may comprise a solid material that is connected or integrated with the body 102, such that it functions as a stop for the shaft 110 when the device is normally operating between "closed" and "open" states of the circuit. However, during operation of the pyrotechnic disconnect elements, the rigid stop 113 may be intentionally provided to "fail" as a stop structure and break or tear to allow the shaft 110 to enter the separate compartment 206 of the body.

[0059] In some embodiments, the piston structure 204 may 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. This may be done, for example, by interacting with a position of the piston structure 204, e.g., a portion of the piston stop portion 352 configured to interact or mate with another portion of the piston structure 204.

[0060] In some embodiments, the piston structure 204 will not have the opportunity to contact the piston stop portion 352 until the piston structure 204 has been moved by activation of the pyrotechnic charge 202. This causes the piston structure 204 to be held between the piston stop portion 352 and the movable contact 108, when the pyrotechnic charge 202 has been activated and the piston structure 204 has been pushed out of its rest position. As shown in [Fig. 3], this configuration places the piston structure 204 in a position that holds or locks the piston structure 204 against the movable contact 108. The piston structure 204 holds the movable contact 108 in place and helps maintain the circuit breaker space gap 350 so that the fixed contacts 104, 106 and the movable contact 108 cannot slide into contact with each other, rendering the contactor device 100 inoperative.

[0061] In some embodiments, instead of or in addition to the piston stop portion 352 of the body 102, the separate compartment 206 of the body 102 may include 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 passed into the separate compartment 206 due to activation of the pyrotechnic charge 202.

[0062] In some embodiments, the separate compartment may be configured to interact with the torn rigid stop 113 or other structure connected to the shaft 110 that has passed 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 as part of ordinary operation of the device, but are pushed into the separate compartment 206 during the pyrotechnic cycle during the shielding operation. against overcurrents. The separate compartment 206 includes sufficient size and shape, or additional features, e.g., features configured to interact or mate with corresponding features on the shaft 110 or a connected structure, to hold the shaft 110 in place so that the movable contact 108 connected to the shaft 110 cannot slide and come into contact with the fixed contacts 104, 106.

[0063] In addition to the foregoing elements, the contactor device 100 of [Figs. 1] to 3 may further comprise a printed circuit board 400. As explained in the remainder of this document, the printed circuit board allows efficient and convenient connection of the internal components of the contactor device 100 to pyrotechnic triggering configurations incorporating elements of the present invention. The printed circuit board 400 may be a printed circuit board adapted to receive pyrotechnic triggering configurations incorporating elements of the present invention. In the embodiment shown in [Figs.l] to 3, the printed circuit board 400 is shown as being located near the top of the contactor device 100; however, it is understood that the printed circuit board 400 may be located in or on any part of the contactor device 100 and may be internal to the contactor device 100 or external to the contactor device 100.

[0064] Aside from contactor devices, which may serve to prevent or allow the flow of electrical flux through the device during ordinary operation, another type of switching device that may serve as an example of an environment for use with passive pyrotechnic triggering configurations is fusible devices. Fusible devices allow electricity to flow through the device only during ordinary operation and function as a sacrificial circuit breaker when a threshold current level flows through the device. [Figs. 4] and 5 show an example of a fusible device 430 of this type, which includes similar elements and operates in a manner similar to that of the contactor device 100 of [Figs. 1] through 3, but without including some of its elements, such as a solenoid or other mechanism for opening and closing the fixed and movable contacts.In ordinary operation, the fusible device 430 is constantly in a "closed" state allowing current to flow through the device, until the pyrotechnic elements are activated, resulting in the device being in a now "open" state preventing current from flowing through the device. [Fig. 4] and 5 show a body 432 (similar to the body 102 of [Fig. 1] to 3 above), fixed contacts 434, 436 (similar to the fixed contacts 104, 106 of [Fig. 1] to 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 to enable their connection to an external circuit, the power terminals and the fixed contacts being a single element in the embodiment of [Fig.l] to 3. [Fig.4] and 5 further show movable contacts 442 (similar to the movable contact 108 of [Fig.l] to 3 above), a shaft structure 444 (similar to the shaft structure 110 of [Fig.l] to 3 above, but of a different shape).

[0065] The shaft structure 444 is connected to the movable contact 442 and the piston structure 446 (which is similar to the piston structure 204 of [Fig. 1] to 3 above). The piston structure 446 may at least partially surround a pyrotechnic charge 448, such that when the pyrotechnic charge 448 is activated, the movable contact 442 and the piston structure 446 are pushed in a direction away from the fixed contacts 434, 436, thereby breaking the circuits. In some embodiments, the fusible device 430 may include a support structure 450 configured to help hold the fixed contacts 434, 436 and the movable contacts 442 in place. In some embodiments, firing the pyrotechnic charge 448 causes the piston structure 446 to move away from the pyrotechnic charge with such force that the support structure 450 breaks or displaces.In some embodiments, the fusible device 430 may be triggered by active signals. In some embodiments, the fusible device 430 may be triggered by passive triggering configurations, such as those discussed herein. [Fig. 4] shows the fusible device 430 in its "closed" state, in which the fixed contacts 434, 436 and the movable contacts 442 are together and electrical flow through the device 430 is permitted. Conversely, [Fig. 5] shows the fusible device 430 in its "open" state after triggering the pyrotechnic charge 448, in which the fixed contacts 434, 436 and the movable contacts 442 are separated and electrical flow through the device 430 is blocked.

[0066] Since two types of switching devices, contactors and fuse devices, have been described as examples of environments that can use pyrotechnic triggering mechanisms according to the present invention, embodiments of pyrotechnic triggering mechanisms can now be described more fully. In the following embodiments described in light of [Fig. 6] to 11, the pyrotechnic triggering configurations are described in terms of their application to the contactor device of [Fig. 1] to 3. However, it is understood that the pyrotechnic triggering configurations described in light of [Fig. 6] to 11 can be applied as triggering devices in any switching mechanism incorporating elements pyrotechnics including, for example, the fuse device described in connection with [Fig.4] and 5.

[0067] [Fig. 6] shows a pyrotechnic trigger configuration 500 including a printed circuit board 502 (traces not shown), similar to the printed circuit board 400 of [Figs. 1] to 3, power supply terminals 504, similar to the fixed contact structures 104, 106 of [Figs. 1] to 3, and a passive trigger switch 506. [Fig. 6] further shows the pyrotechnic trigger configuration 500 integrated with an electrical device 503, including a body 508, which may be similar to the body 102, containing internal components. The pyrotechnic trigger configuration 500 of [Fig. 6] is shown without the upper "cap" portion of the body so that the printed circuit board 502 is visible and exposed, but it is understood that under normal operating conditions of the device, features such as a closed body including a cap and an epoxy-based material may be included.[Fig. 6] also shows pyrotechnic pins 510 which are similar to the pyrotechnic pins 203 of [Fig. 1] to 3. Coil pins 512 are included which allow electrical connection to an internal coil or solenoid, similar for example to the solenoid 112 of [Fig. 1] to 3. A tubing structure 514 is also included which may facilitate the formation of an internal hermetic seal or the management of electronegative gases within the electrical device 503.

[0068] During operation of the pyrotechnic trigger configuration 500 of [Fig. 6], when a predetermined current level flows through the device 503, for example, a current level indicating a dangerous current level that may result in irreversible damage to a device or the creation of a hazard such as a fire, the passive trigger switch 506 will activate. This then has the effect of completing a circuit to transmit a signal to the pyrotechnic pins 510, thereby activating an internal pyrotechnic element, for example, such as the pyrotechnic charge 202 of [Figs. 1] through 3. In these embodiments, the printed circuit board 502 may be configured to send a trigger signal to the pyrotechnic pins 510, which are in electrical communication with pyrotechnic elements internal to the device 503.The electrical path of this trigger signal may be linked to the closure or activation of the passive trigger switch 506, such that when the passive trigger switch 506 is open or untriggered (in an idle state), the electrical path of the trigger signal to the pyrotechnic pins 510 is blocked. Similarly, when the passive trigger switch 506 is closed or activated, the trigger signal may be directed to the pyrotechnic pins 510 and trigger the internal pyrotechnic element.

[0069] The passive trigger switch 506 may be connected to a sensor that is configured to detect that a predetermined current level is flowing through the device 503, the sensor signaling the passive trigger switch 506 to trigger. In some embodiments, it is the passive trigger switch 506 itself that is configured to detect or passively respond and trigger when the current flowing through the device 503 reaches a predetermined level. For example, in some embodiments, the passive trigger switch 506 includes a switch configured to respond to a magnetic field generated by current flowing through the power supply terminals 504 of the device 503 or from current flow through a region of the device 503.

[0070] 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 may be used with a reed switch. For example, the reed switch may be configured so that the contacts are open at rest and close when a sufficient magnetic field is present, or closed at rest and open when a sufficient magnetic field is present. Further, in some embodiments, the reed switch may be arranged in a reed relay and be actuated by a magnetic coil.In most embodiments incorporating a reed switch, the reed switch is configured so that the contacts are open at rest, preventing an electrical signal from reaching the pyrotechnic pins 510 and activating the pyrotechnic elements until a sufficient magnetic field corresponding to a dangerous current level closes the reed switch.

[0071] In some embodiments, the printed circuit board 502 includes a plurality of passive trigger switch mounting elements 516, which allow the pyrotechnic trigger configuration 500 to be adjusted according to the desired trigger current. For example, [Fig. 7] shows the pyrotechnic trigger configuration 500, the printed circuit board 502, the electrical device 503, the power supply terminals 504, the passive trigger switch 506, the body 508, the pyrotechnic pins 510, the coil pins 512, the tubing structure 514, and the trigger switch mounting elements 516. As shown in [Fig.7], the desired trigger current can be set by mounting the passive trigger switch 506 to another of the trigger switch mounting members 516, which in turn sets the trigger distance 518 between the passive trigger switch 506 and one or more of the power supply terminals 504.

[0072] By adjusting the trigger 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 thereby trigger the internal pyrotechnic elements of the device, can be adjusted. For example, the passive trigger switch 506 may include a reed switch that is configured to activate when a predetermined magnetic field is generated due to a predetermined current level flowing through the power terminals 504.The magnetic field strength required to trigger the passive trigger switch 506, and thus the corresponding current level flowing through the device and required to trigger the passive trigger switch 506, can be adjusted by simply changing the trigger distance 518 between the passive trigger switch 506 and the power terminals 504. In the illustrated embodiment, this can be accomplished by mounting the passive trigger switch 506 on another passive trigger switch mounting member 516.

[0073] By moving the passive trigger switch 506 further away from the power terminal 504, a larger magnetic field, and therefore a larger current, is required to trigger the passive trigger switch 506 and thus trigger the pyrotechnic elements of the device 503. This allows for a pre-designed switching device to be provided with a pre-designed printed circuit board so that the device can be mass-produced, while still allowing different trigger currents depending on the installation of the passive trigger switch 506 on another of the passive trigger switch mounting elements 516.For example, the passive trigger switch mounting elements 516 may be located at locations on the printed circuit board 502 corresponding to different magnetic field strength levels, which in turn may correspond to different desired trigger current levels. A company may manufacture a printed circuit board configuration and may place the passive trigger switch 506 on other passive trigger switch mounting elements 516 to create devices that will trigger with different currents. In embodiments using a coil or solenoid, for example, as with contactors, the passive trigger switch 506 may be configured to remove power from the coil. In these embodiments, this configuration may decrease the time it takes for the pyrotechnic elements to open the contacts since it does not have to resist the coil..

[0074] In other embodiments, additional features may be included instead of, or in addition to, the trigger switch mounting features 516 to further interact with the passive trigger switch 506. For example, [Fig. 8] shows a device 603 having a pyrotechnic trigger configuration 600 similar to the pyrotechnic trigger configuration 500 of [Fig. 6] and 7. The device 603 includes a printed circuit board 602 (similar to the printed circuit board 502 of [Fig. 7]), an electrical device 603 (similar to the electrical device 503 of [Fig. 7]), and power supply terminals 604 (similar to the power supply terminals 504 of [Fig. 7]). The device 603 further comprises a passive trigger switch 606 (similar to the passive trigger switch 506 of [Fig. 7]), a body 608 (similar to the body 508 of [Fig.7]), pyrotechnic pins 610 (similar to pyrotechnic pins 510 of [Fig. 7]), coil pins 612 (similar to coil pins 512 of [Fig. 7]), and a tubing structure 614 (similar to tubing structure 514 of [Fig. 7]). Although similar embodiments may include trigger switch mounting features, the embodiment shown in [Fig. 8] does not include any trigger switch mounting features. Instead, the pyrotechnic trigger configuration 600 includes a core structure 630 that helps determine the target trigger current of the pyrotechnic trigger configuration 600.

[0075] The core structure 630 may comprise any known material capable of channeling, directing, or controlling a magnetic field generated by a current flowing through the device 603. For example, in some embodiments, the core structure 630 comprises a 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 may 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-shaped strip.The core structure 630 may be configured in any spatial position relative to the device 603 and the printed circuit board 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 power supply terminals 604 and is adjacent to the passive trigger switch 606.

[0076] The magnetic field generated from the core structure 630 may be larger than that of the power terminal itself, and the desired trigger current may 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 [Fig. 6] and 7. For example, [Fig. 9] shows the pyrotechnic trigger configuration 600, the printed circuit board 602, the electrical device 603, the power supply terminals 604, the passive trigger switch 606, the body 608, the pyrotechnic pins 610, the coil pins 612, the tubing structure 614, and the core structure 630. [Fig. 9] further shows the trigger distance 636 between the passive trigger switch 606 and core structure 630.As with the embodiment of [Fig. 7] and 8, the passive trigger switch 606 may comprise a reed switch, or other passive mechanism, which is configured to activate when a predetermined magnetic field is generated due to a predetermined current level flowing through the power terminal 604 and / or the core structure 630.

[0077] The strength of the magnetic field required to trigger the passive trigger switch 606, and therefore the corresponding current level flowing through the device and required to trigger the passive trigger switch 606, can be adjusted by simply changing the trigger distance 636 between the passive trigger switch 606 and a portion of the core structure 630. By moving the passive trigger switch 606 further away from the core structure 630, a larger magnetic field, and therefore a larger current, would be required to trigger the passive trigger switch 606 and thus to trigger the pyrotechnic elements of the device 603.

[0078] In some embodiments, instead of or in addition to the trigger switch mounting elements 606 or a core structure 630, an external trigger mechanism may be used. In some embodiments, this external trigger mechanism may replace the need for a printed circuit board, although in other embodiments, the external trigger mechanism may be used in addition to a printed circuit board. An exemplary embodiment in which an external trigger mechanism replaces the need for a printed circuit board is shown in [Fig. 10]. [Fig. 10] shows a pyrotechnic trigger configuration 700 (similar to the pyrotechnic trigger configuration 600 of [Fig. 8]). The configuration 700 includes an electrical device 703 (similar to the electrical device 603 of [Fig. 8]), power supply terminals 704 (similar to power supply terminals 604 of [Fig. 8]), a passive trigger switch 706 (similar to passive trigger switch 606 of [Fig. 8]), a body 708 (similar to body 608 of [Fig. 8]), pyrotechnic pins 710 (similar to pyrotechnic pins 610 of [Fig. 8]), access points 712, which may provide wired access to an internal solenoid or coil, and a tubing structure 714 (similar to tubing structure 614 of [Fig. 8]). [Fig. 10] also shows the body 708 including a top portion or cap 716, through which the power supply terminals 704 protrude.

[0079] It is understood that a top portion or cap portion similar to the top or cap portion 716 of the body 708 shown in [Fig. 10] may be applied to all other embodiments incorporating elements of the present invention. For example, it is understood that the device embodiments of [Fig. 6] and [Fig. 8] are shown without the cap portion to better illustrate the underlying printed circuit board configurations. However, upon final assembly, the embodiments of [Fig. 6] and [Fig. 8] may have all internal components completely enclosed within the body and include a cap portion of the body.

[0080] The embodiment of [Fig. 10] further shows an external trigger mechanism 730, which includes the passive trigger switch 706, a conductive bus bar 732, and a spacer portion 734. As shown in [Fig. 10], the conductive bus bar 732 may include several connection portions, the conductive bus bar 732 of the shown embodiment including a first connection point 736, which is configured to be connected to the device 708 at one of the power terminals 704, and a second connection point 738 configured to be connected to an external power source.

[0081] The conductive bus bar 732 may comprise any conductive material, for example, a metallic material. In some embodiments, the conductive bus bar 732 comprises copper. The spacer portion 734 may comprise a non-magnetic material. The conductive bus bar 732 may be configured to allow current to flow to the pyrotechnic pins 710 and thus to trigger the internal pyrotechnic elements of the device 703. The passive trigger switch 706, similar to the passive trigger switches of the embodiments of [Fig. 6] and 8, is configured in an open state, which does not allow electrical current to flow through the conductive bus bar 732 and therefore allows the pyrotechnic elements to be triggered.

[0082] When the current from the device 703 reaches a threshold level, a sufficient magnetic field is generated to trigger the passive trigger switch 706. This 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 thereby trigger the pyrotechnic elements of the device.

[0083] The threshold magnetic field required to activate the passive trigger switch 706, and therefore the necessary current level defined as sufficiently dangerous to justify activation of the pyrotechnic circuit breaker elements, can be adjusted by adjusting the distance of the passive trigger switch 706 from the conductive bus bar 732. This result can be achieved, for example, by adjusting the thickness of the non-magnetic spacer portion 734. For example, [Fig. 11] shows a cross-sectional and close-up view of the external trigger 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 trigger distance 750, which corresponds to the thickness of the non-magnetic spacer portion 734.

[0084] As with the embodiments described above, the passive trigger switch 706 may comprise a reed switch, or other passive mechanism. The switch may be configured to activate when a predetermined magnetic field is generated due to a predetermined current level flowing through the power terminal 604, in this case, the power terminal 604 that is in electrical connection with the external trigger mechanism 730. The magnetic field strength necessary to trigger the passive trigger switch 706, and therefore the corresponding current level flowing through the device 703 necessary to trigger the passive trigger switch 706, may be adjusted by simply changing the trigger 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 further away 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 to trigger the pyrotechnic elements of the device 703. Similarly, by moving the passive trigger switch 706 closer to the conductive bus structure 732, a lesser magnetic field, and therefore a lesser current, would be required. to trigger the passive trigger switch 706 and thus to trigger the pyrotechnic elements of the device 703.

[0085] It is understood that the various pyrotechnic passive switching circuits may be arranged in a variety of ways in accordance with the present invention. [Fig. 12] shows a simplified diagram of one embodiment of pyrotechnic passive switching circuit 800 in accordance with the present invention. Circuit 800 generally includes a utility power circuit 802 that includes the standard utility power source 804 coupled to a utility load 806 that is activated and powered by the power source 804. A contactor or fuse 808 is arranged in circuit 800 to break the electrical connection between the power source 804 and the load when a hazardous current flows in circuit 802. It is understood that fuse 808 may also include features that enable it to function as a contactor to disconnect the power source 804 from the load under normal operating conditions.It is also understood that the fuse 808 may include a contactor where the passive switching circuit 800 operates by changing the state of the contactor to break the circuit path as explained above.

[0086] A pyrotechnic activation circuit 810 may be included, which is intended to work with the service power circuit 802 for protection against overcurrent conditions. The circuit 810 includes a pyrotechnic actuator / activator 812 as described above, which is intended to change the state of the fuse 808 when activated. The circuit also includes an overcurrent actuated pyrotechnic fuse trip device 814 which is arranged adjacent to the circuit 802 in a position that enables it to detect an overcurrent condition in the circuit 802. In the embodiment shown, the trip device 814 may include a reed switch, but it is understood that many other devices may be used.The trigger 814 may be disposed at multiple locations relative to the circuit 802, such as adjacent to a power terminal as described above, or adjacent to other circuit conductors carrying utility current. The circuit 810 may also include a secondary power source 816 that may be coupled to the pyrotechnic actuator 812 when the fuse trigger is closed in response to high current levels.

[0087] In use, fuse 808 is closed, allowing power from service power source 804 to supply load 806. When normal current levels flow through circuit 802, trigger 814 remains open and secondary power source 816 is disconnected from pyrotechnic actuator 812. When currents above a certain level (dangerously high levels) flow through circuit 802, trigger 814 closes in response to the high magnetic field. This connects the secondary power source to the pyrotechnic actuator 812, causing the latter to actuate and cut off the fuse 808. This disconnects the service power source 804 from the load 806, in order to cut off the conductive path for the high current in the circuit 802.

[0088] It is understood that other circuits according to the present invention may be arranged in multiple ways with multiple different devices and elements. Multiple different secondary power sources may be used, with some embodiments using an onboard battery or capacitor circuit storing sufficient charge to trigger the pyrotechnic actuator 812. In other embodiments, the secondary power source may comprise an onboard low voltage power supply that remains sufficient to trigger the pyrotechnic actuator 812.

[0089] [Fig. 13] shows another embodiment of a pyrotechnic passive switching circuit 900 according to the present invention, which contains many of the same elements as the switching circuit 800 shown in [Fig. 12]. The circuit 900 includes a utility power circuit 902 which includes the standard utility power source 904 coupled to a utility load 906. A contactor or fuse 908 is provided in the circuit 900 to break the electrical connection between the power source 904 and the load 906 when a dangerous current flows in the circuit 902.

[0090] Circuit 900 includes a pyrotechnic actuator / activator 912 and an overcurrent actuated pyrotechnic fuse trip device 914 similar to those described above. However, in circuit 900, these elements are not provided in a separate pyrotechnic activation circuit operating with a secondary power source to trigger pyrotechnic actuator 912. Instead, these elements are integrated with service power circuit 902, with trip device 914 being provided to sense high currents in circuit 902 and also coupled to circuit 902 at a conductor carrying the high current. In the illustrated embodiment, trip device 914 is coupled to the circuit conductors in parallel with fuse 908, but it is understood that it may be arranged in other ways.

[0091] Under normal operating conditions, trigger 914 is open and energy from power source 904 is conducted to load 906 through fuse 908. When trigger 914 senses a high current, it closes and the high current flows through trigger 914 to pyrotechnic actuator 912, triggering the actuator and blowing fuse 908. This has the effect of severing the normal conduction path between power source 904 and load 908.

[0092] Trigger 914 is also arranged so that high current from power source 904 quickly breaks or otherwise destroys trigger 914, thereby severing the current path through trigger 914. Trigger 914 carries current long enough to activate the actuator, but is destroyed soon afterward. As a result, power source 904 is electrically isolated from load 906 and any high current path is severed. It is understood that trigger 914 and actuator 912 may include features that will confine them in the event of failure or triggering, such as an encapsulating material such as epoxy.

[0093] It is also understood that the circuit elements of the present invention may be coupled to each other using multiple different electrical conductors. This may include conductive paths on a printed circuit board, or wires. It is also understood that the circuits described above may be arranged on and integral with the contactor or fuse, to provide a simple to use and small device. The circuit 900 may provide certain advantages, including not requiring a separate secondary power source to activate the pyrotechnic actuator 912. This provides a simplified and less expensive device.

[0094] 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 may include any combination of compatible elements shown in the various FIGS., and such embodiments are not intended to be limited to those expressly illustrated and described herein. Accordingly, the spirit and scope of the invention are not intended to be limited to the versions described above.

[0095] The foregoing is intended to cover all modifications and alternative constructions within the spirit and scope of the invention, wherein no part of the invention is intended, expressly or by implication, to be intended for the public domain unless so stated in any of the claims.

Claims

Claims

1. An electrical switching device, comprising: a housing (102, 432, 508, 608, 708); internal components within said housing, said internal components being configured to change the state of said switching device from a closed state that allows current to flow through said switching device to an open state that interrupts the flow of current through said switching device; pyrotechnic elements configured to interact with said internal components to change said switching device from said closed state to said open state when said pyrotechnic elements are activated;a passive trigger switch structure (506, 606, 706) configured to activate said pyrotechnic elements when triggered, said passive trigger switch structure being configured to trigger in response to a magnetic field reaching a threshold intensity when a threshold current level flows through said switching device; and power terminals (104, 106, 438, 440, 504, 604, 704) electrically connected to said internal components to enable their connection to an external circuit.;

2. An electrical switching device according to claim 1, wherein said passive trigger switch (506, 606, 706) comprises a reed switch.

3. An electrical switching device according to claim 1, wherein said passive trigger switch (506, 606, 706) is connected to a printed circuit board (400, 502, 602).

4. An electrical switching device according to claim 3, wherein said threshold intensity of said magnetic field is determined at least in part by the distance (518, 636) of said passive trigger switch (506, 606, 706) from at least one of said power terminals (104, 106, 438, 440, 504, 604, 704).

5. An electrical switching device according to claim 4, wherein said printed circuit board (400, 502, 602) comprises a plurality of passive trigger switch mounting elements (516).

6. An electrical switching device according to claim 5, wherein said plurality of passive trigger switch mounting elements (516) are configured at locations at different distances from at least one of said power terminals (104, 106, 438, 440, 504, 604, 704) such that said locations correspond to different desired trigger thresholds based on different threshold magnetic field strengths.

7. An electrical switching device according to claim 3, further comprising at least one core structure (630).

8. An electrical switching device according to claim 7, wherein said core structure (630) at least partially surrounds at least one of said power terminals (104, 106, 438, 440, 504, 604, 704).

9. An electrical switching device according to claim 8, wherein said threshold intensity of said magnetic field is determined by the distance (518, 636) of said passive trigger switch (506, 606, 706) from a portion of said at least one core structure (630).

10. An electrical switching device, comprising: a housing (102, 432, 508, 608, 708); internal components within said housing, said internal components being configured to change the state of said switching device from a closed state that allows current to flow through said switching device to an open state that interrupts the flow of current through said switching device; a pyrotechnic element configured to interact with said internal components to change said switching device from said closed state to said open state when said pyrotechnic elements are activated;a passive trigger switch structure (506, 606, 706) configured to activate said pyrotechnic element when triggered, said passive trigger switch structure being configured to trigger in response to a high current signal flowing through said switching device, said; a passive trigger switch (506, 606, 706) being provided to use said high current signal to activate said pyrotechnic element; at least one power terminal (104, 106, 438, 440, 504, 604, 704); and a plurality of passive trigger switch mounting elements (516) configured at locations at different distances from at least one of said power terminals (104, 106, 438, 440, 504, 604, 704) such that said locations correspond to different desired trigger thresholds based on different threshold intensities of the magnetic field.

11. An electrical switching device according to claim 10, wherein said passive trigger switch (506, 606, 706) comprises a reed switch.

12. An electrical switching device according to claim 10, wherein said passive trigger switch (506, 606, 706) is connected to a printed circuit board (400, 502, 602).

13. An electrical switching device according to claim 12, wherein said printed circuit board (400, 502, 602) comprises said plurality of passive trigger switch mounting elements (516).

14. 14. An electrical switching device according to claim 10, further comprising a power terminal (104, 106, 438, 440, 504, 604, 704), wherein said passive trigger switch (506, 606, 706) is arranged to trigger in response to a high current in said power terminal.

15. 5 An electrical system, comprising: a utility power circuit (802, 902) comprising a utility power source (804, 904) coupled to a utility load (806, 906) by a current path, with a contactor (808, 908) between said power source and said load; a pyrotechnic trigger circuit (810) comprising a trigger / switch (814, 914) arranged to detect a high current in said utility power circuit (802, 902); and a pyrotechnic actuator (812, 912), said trigger / switch (814, 914) responsively cutting off the high current in said utility power circuit (802, 902) and carrying long enough for said high current to activate said pyrotechnic actuator to act on said contactor (808, 908) to interrupt said current path in said service supply circuit (802, 902), said trigger / switch (814, 914) being destroyed by the high current after activation of the pyrotechnic actuator (812, 912).

16. 16. The system of claim 15, wherein said contactor comprises internal components within a housing (102, 432, 508, 608, 708), said internal components being configured to change the state of a switching device from a closed state that allows current to flow through said contactor (808, 908) to an open state that interrupts the flow of current through said contactor.

17. 17. The system of claim 16, wherein said pyrotechnic actuator (812, 912) interacts with said internal components to transition said contactor (808, 908) from said closed state to said open state when said pyrotechnic actuator is activated.

18. 18. The system of claim 16, wherein said trigger circuit (810) uses said high current to activate said pyrotechnic actuator (812, 912).

19. 19. The system of claim 16, wherein said trigger circuit (810) uses a secondary power source (816) to activate said pyrotechnic actuator (812, 912).

20. 20. The system of claim 19, wherein said secondary power source (816) comprises a battery, a capacitor circuit, or a low voltage power supply.

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