Electrical circuit equipped with two pyrotechnic switches allowing to electrically isolate a section in the event of a short-circuit fault.

Abstract

An aircraft electrical circuit (100) comprising a power supply (4) electrically connected to an electrical load (31) by means of a conductive element (7), and a main electrical protection element (6) characterized in that it comprises a first pyrotechnic switch (1) provided with at least one first initiating element (11) and at least one first mechanical breaking element (12), and a second pyrotechnic switch (2) provided with at least one second initiating element (21) and at least one second mechanical breaking element (22), the first initiating element (11) and the second initiating element (21) each being electrically positioned in parallel with at least one main electrical protection element (6). Figure 1

Description

Title of the invention: Electrical circuit equipped with two pyrotechnic switches allowing to electrically isolate a section when a fault of the short-circuit type occurs. technical field

[0001] The invention relates to the field of electrical circuits and more particularly to an electrical circuit for supplying at least one electrical load of an aircraft. Prior art

[0002] In the present description, the term "aircraft" refers to a set of devices capable of moving in the air, such as conventional aircraft also designated by the acronym CTOL (Convention Take Off and Landing), vertical take-off and landing aircraft designated by the acronym VTOL (vertical take off and landing), and short take-off and landing aircraft designated by the acronym STOL (Short take off and landing).

[0003] It is known that aircraft include an electrical load, that is to say, a device that consumes electricity in normal operation. For example, the electrical load may be an electric propulsion system comprising at least one electric motor.

[0004] Electric propulsion is powered by an electrical circuit supplying a high voltage direct current, for example greater than 800V.

[0005] It is known that the electrical circuit comprises at least one power supply, at least one distribution box and at least one distribution harness.

[0006] The power supply corresponds to an electrical generator such as, for example, a battery.

[0007] The distribution box includes at least one switching element, for example a contactor, allowing the distribution harness, and therefore ultimately the electric propulsion, to be switched on or off.

[0008] The distribution harness, comprising at least one conductive element such as an electrical cable, carries the electrical energy from the distribution box to the electric propulsion.

[0009] In the following description, upstream and downstream are defined with respect to a normal direction of supply of the electric load (from upstream to downstream), that is to say from the electric supply to the electric load.

[0010] Finally, the electrical circuit is electrically protected in the event of a short-circuit fault by at least one electrical protection device, such as a fuse. This electrical protection device can be positioned, for example, at the level of the distribution box, downstream of the switching element and upstream of the distribution harness.

[0011] An arrangement of the different elements of the electrical circuit is called the architecture of the electrical circuit.

[0012] With such an architecture, when a short-circuit type fault appears in the distribution harness, the electrical protection makes it possible to cut an electrical link between the power supply and the electric propulsion, so as to protect the distribution harness against degradation related to the fault.

[0013] However, when the electrical load is reversible, it can then become a generator and re-energize the short-circuit fault. This is particularly true when the electrical load is an electric motor. In this case, the re-energizing of the electrical fault by the electric motor, which becomes a generator, is also called the windmilling effect.

[0014] Re-energizing the electrical short-circuit fault presents a danger to aircraft safety. Indeed, it may be able to degrade the aircraft's integrity, for example by perforating a wing bulkhead.

[0015] To prevent the short-circuit fault from recurring as described above, additional electrical protection must be added between the distribution harness and the electrical load. This additional electrical protection must be fast and have the lowest possible power dissipation. Finally, physically integrating this additional electrical protection into the aircraft also presents difficulties.

[0016] The invention therefore aims to provide an electrical circuit architecture for powering an aircraft's electrical load that prevents re-powering in the event of a short-circuit fault, while being easily integrated into an aircraft. Description of the invention

[0017] One embodiment relates to an electrical circuit for supplying at least one electrical load of an aircraft, the electrical circuit comprising at least one electrical supply electrically connected to at least one electrical load by means of at least one conductive element, and at least one main electrical protection element positioned between the at least one electrical supply and an upstream point of a section of the at least one conductive element to be protected in the event of an electrical fault, characterized in that the electrical circuit comprises at least one first pyrotechnic switch equipped with at least one first initiating element and at least one first mechanical breaking element which is configured to effect an electrical break of the at least one conductive element between the at least one electrical supply and the upstream point of the section to be protected,and at least one second pyrotechnic switch equipped with at least one second element, initiator and at least one second mechanical breaking element which is configured to effect an electrical break of at least one conductive element between a downstream point of the section to be protected and the electrical load, the first initiating element and the second initiating element each being electrically positioned in parallel with at least one main electrical protection element.

[0018] The at least one electrical load corresponds to a device that consumes electricity during normal operation. For example, the electrical load may be an electric propulsion system comprising at least one electric motor that must be powered by a high-voltage direct current, for example, greater than 800Vdc.

[0019] A power supply is an element that provides electrical energy to the electrical circuit. The power supply includes an electrical generator such as, for example, a battery.

[0020] The conductive element is configured to carry an electric current to power the electrical load. The conductive element includes a section to be protected in the event of an electrical fault, for example, a short circuit. In other words, it is a section that must be electrically isolated following the occurrence of the electrical fault in said section. This section is located between an upstream point and a downstream point.

[0021] In the following description, upstream and downstream are defined with respect to a normal direction of supply of the electric load (from upstream to downstream), that is to say from the electric supply to the electric load.

[0022] The main electrical protection element is configured in an energized state to allow the flow of electrical current to power the electrical load, and to be in a tripped state upon the occurrence of an electrical fault in the section of the conductor to be protected. The energized state is the state of the main electrical protection element during normal operation of the electrical circuit. The positioning of the main electrical protection element between the power supply and the upstream point of the section to be protected allows the main electrical protection element to be subjected to the short-circuit current. The main electrical protection element is in the tripped state when the electrical current across its terminals exceeds a maximum electrical current.

[0023] Pyrotechnic switches can be in a closed state, in which they allow electric current to flow through the conductive element, or in an open state, in which electric current can no longer flow through the conductive element. The closed state is the state of the pyrotechnic switches during normal operation of the electrical circuit. The pyrotechnic switches are only in an open state when an electrical fault occurs.

[0024] Each pyrotechnic switch comprises an initiating element and a mechanical cutting element.

[0025] The pyrotechnic charge controlled by the initiating element is in a nominal state as long as the electrical voltage across its terminals is less than a tripping voltage. The nominal state is the state of the initiating element during the normal operation of the electrical circuit. The pyrotechnic charge controlled by the initiating element is in a tripped state when the voltage across its terminals has become greater than or equal to the tripping voltage for at least one instant, such as when an electrical fault occurs. A certain duration, called the tripping response time, is required for the initiating element to transition from the nominal state to the tripped state.

[0026] In some embodiments, the trigger voltage of the first initiating element is equal to the trigger voltage of the second initiating element.

[0027] The mechanical switching element is a movable element, for example, a translational one, configured to provide an electrical break in the conductive element. The mechanical switching element can be in a nominal state or in an actuated state. The nominal state is the state of the mechanical switching element during the normal operation of the electrical circuit. The mechanical switching element is in an actuated state when the initiating element has transitioned to a triggered state. A certain duration, called the mechanical response time, is required for the mechanical switching element to transition from the nominal state to the actuated state. The mechanical switching element interrupts the conductive element at the position of the pyrotechnic switch.In other words, as the first mechanical breaking element cuts the conductive element between the power supply and the upstream point of the section to be protected, the first pyrotechnic switch is positioned between the power supply and the upstream point of the section to be protected, and as the second mechanical breaking element cuts the conductive element between the downstream point of the section to be protected and the electrical load, the second pyrotechnic switch is positioned between the downstream point of the section to be protected and the electrical load.

[0028] The first and second switches are mechanically positioned in series along the conductive element. This electrical positioning increases the breaking capacity of each pyrotechnic switch, so that the first and second pyrotechnic switches can be sized with a working voltage corresponding to half the voltage of the power supply applied to the electrical load.

[0029] When the pyrotechnic charge controlled by the initiating element is in the nominal state, the mechanical cutting element is also in the nominal state and the pyrotechnic switch is in the closed state.

[0030] When the pyrotechnic charge controlled by the initiating element is in the state triggered, the mechanical cutting element is in the actuated state and the pyrotechnic switch is in the open state.

[0031] The mechanical breaking element is configured to break an electrical link at the positioning of the pyrotechnic switch in the electrical circuit, when the mechanical breaking element is actuated by the initiating element.

[0032] In the electrical circuit according to the invention, the first and second pyrotechnic switches are configured to interrupt the conductive element between the power supply and the electrical load upon the occurrence of an electrical fault, so as to isolate the section to be protected. More specifically, the first pyrotechnic switch is configured to interrupt the conductive element between the power supply and the upstream point of the section to be protected, while the second pyrotechnic switch is configured to interrupt the conductive element between the downstream point of the section to be protected and the electrical load.

[0033] As described above, the pyrotechnic switches are positioned in the open state when the voltage across the terminals of the initiating element has become greater than or equal to the triggering voltage of the pyrotechnic charge.

[0034] According to the invention, the first initiating element and the second initiating element are each electrically positioned in parallel with at least one main electrical protection element. Thus, the voltage across the first and second initiating elements is identical and equal to the voltage across the main electrical protection element. Therefore, if the voltage across the main electrical protection element becomes greater than or equal to the triggering voltage of the pyrotechnic charge, the voltage across the first and second initiating elements also becomes greater than or equal to the triggering voltage, causing the first and second initiating elements to transition to the triggered state, resulting in the first and second mechanical switching elements transitioning to the activated state, and ultimately the two pyrotechnic switches transitioning to the open state.Thus, the electrical circuit according to the invention does not include specific electronics to actuate the pyrotechnic switches. It is directly an overload current linked to the short circuit that triggers the pyrotechnic switches.

[0035] When an electrical fault occurs in the section to be protected, the main electrical protection element will detect an overload current and switch to the tripped state. At least during the transition from the energized to the tripped state, an electric arc forms across the terminals of the main electrical protection element. This electric arc results in a voltage across the terminals of the main electrical protection element that is greater than or equal to the tripping voltage of the pyrotechnic switches, and therefore also across the terminals of the first initiating element and the second Initiating element. The first and second initiating elements thus transition to the triggered state, thereby activating the first and second mechanical breaking elements, which then transition to the activated state. Finally, the first and second pyrotechnic switches are therefore in the open state. The section of the conductive element is thus electrically separated from the electrical circuit, and the electrical fault is therefore also isolated. There is no longer any possibility of the electrical fault being re-energized by the electrical load, even in the event of a windmilling effect.

[0036] The invention may also have one or more of the following features taken alone or in combination.

[0037] In some embodiments, the response time of a triggering of at least one first and at least one second initiating elements is identical.

[0038] In certain embodiments, the mechanical response time of at least one first and at least one second mechanical cutting elements are identical.

[0039] In certain embodiments, a response time of a triggering of at least one first and at least one second initiating elements is less than a mechanical response time of at least one first and at least one second mechanical cutting elements.

[0040] When an electric arc forms across the terminals of the main electrical protection element, even if the first initiating element receives the tripping voltage slightly before the second initiating element, the first mechanical breaking element only switches to the actuated state once the second initiating element has received the tripping voltage. Thus, both initiating elements are tripped before either of the mechanical elements switches to the actuated state.

[0041] In certain embodiments, at least one first initiating element and / or at least one second initiating element comprises at least one electrical resistor surrounded by a pyrotechnic powder or liquid

[0042] Thus, when the electrical resistance receives a voltage greater than that of its triggering, the resistance heats up, creating an electric arc which powers the electrical resistance of the initiator, leading to the triggering of the pyrotechnic powder or liquid.

[0043] In some embodiments, at least one first mechanical cutting element and / or at least one second mechanical cutting element comprises a sectioning piston.

[0044] When activated, the disconnecting piston moves in translation so as to cut or sever the conductive element. The disconnecting piston can be activated by a detonation or deflagration of the pyrotechnic charge powered by the initiating element.

[0045] In some embodiments, at least one main electrical protection element has a working voltage corresponding to half of the voltage of the electrical supply that is applied to the electrical load.

[0046] Thus, the main electrical protection element is not configured to interrupt an electrical connection between the power supply and the upstream point of the section to be protected. The main electrical protection element only creates an electric arc that will trigger the initiating elements. Since the main electrical protection element cannot be sized to interrupt the conductive element, it is reduced in size, allowing for easier physical integration of the main electrical protection element into the aircraft.

[0047] In some embodiments, at least one main electrical protection element is a fuse.

[0048] In some embodiments, the electrical circuit includes at least one first adjusting resistor positioned electrically in series with the first initiating element and / or at least one second adjusting resistor positioned electrically in series with the second initiating element.

[0049] The adjustment resistor allows limiting a value of the current flowing in the initiating element.

[0050] In some embodiments, the electrical circuit includes at least one distribution box equipped with at least one switching element.

[0051] The distribution box includes at least one switching element, for example a contactor, allowing the conductive element, and therefore ultimately the electrical load, to be switched on or off.

[0052] Another aspect of the invention relates to an aircraft comprising an electrical load powered by an electrical circuit according to the invention. Brief description of the drawings

[0053] The invention will be better understood from the following description, which relates to an embodiment according to the present invention, given by way of non-limiting example and explained with reference to the accompanying schematic drawings, in which:

[0054] [Fig-1] is a schematic representation of an electrical circuit according to the invention;

[0055] [Fig.2] is the schematic representation of the electrical circuit of [Fig.1] in in which an electrical fault appears at the level of a conductive element;

[0056] [Fig.3] is the schematic representation of the electrical circuit of [Fig.2] in which a main electrical protection element passes into a triggered state;

[0057] [Fig.4] is the schematic representation of the electrical circuit of [Fig.3] in in which an electric arc appears at the level of the electrical protection element main ;

[0058] [Fig.5] is the schematic representation of the electrical circuit of [Fig.4] in which a first pyrotechnic switch and a second pyrotechnic switch pass into an open state;

[0059] [Fig.6] is the schematic representation of the electrical circuit of [Fig.5] in which a section of the conducting element is electrically isolated;

[0060] [Fig.7] is the schematic representation of a pyrotechnic switch of the electrical circuit of [Fig.1] in the closed state;

[0061] [Fig.8] is the schematic representation of the pyrotechnic switch of [Fig.7] in the open state; Description of the implementation methods

[0062] In the following description, upstream and downstream are defined with respect to a normal supply direction of the electric load (from upstream to downstream), i.e. from an HV-, HV+ electric supply to an electric load 31.

[0063] Only the elements necessary for understanding the invention have been shown. To facilitate reading the drawings, the same elements bear the same reference numerals from one figure to another.

[0064] Figure 1 shows a schematic representation of an electrical circuit 100 according to the invention. Said electrical circuit 100 comprises a high-voltage power supply 4 HV-, HV+ which is an element that provides electrical energy to the electrical circuit 100. The power supply 4 comprises an electrical generator such as a battery, which provides a high-voltage direct current, for example greater than 800V.

[0065] Said electrical circuit 100 includes an electrical load 31 which corresponds to a device consuming electricity in normal operation. In [Fig. 1], the electrical load 31 is an electric propulsion system comprising an electric motor 31 coupled to an inverter 3 which transforms the high-voltage direct current into an alternating current.

[0066] Electric current flows between the power supply 4 and the electrical load 31 by means of a conductive element 7. The conductive element 7 includes a section AB to be protected in the event of an electrical fault CC, for example, a short circuit. In other words, it is the section AB that must be electrically isolated following the occurrence of the electrical fault CC in said section AB, as illustrated in [Fig. 2]. Said section AB is located between an upstream point A and a downstream point B.

[0067] In the embodiment illustrated in [Fig. 1], the electrical circuit 100 comprises a distribution box equipped with a switching element 5, for example a contactor, allowing the conductive element 7, and therefore ultimately the electrical load 31, to be switched on or off.

[0068] The electrical circuit 100 includes a main electrical protection element 6 positioned between the power supply 4 and the upstream point of the section to be protected AB. The main electrical protection element 4 is configured, in an on state, to allow the flow of electrical current to power the electrical load 31, and to be in a tripped state when the electrical fault CC occurs in the section to be protected AB of the conductive element 7. The main electrical protection element 4 is in the tripped state when the electrical current across its terminals exceeds a maximum electrical current.

[0069] The switched-on state is the state of the main electrical protection element 6 during normal operation of the electrical circuit 100. The main electrical protection element 6 is positioned between the power supply 4 and the upstream point A of the section to be protected AB, so that the main electrical protection element 6 is subjected to the short-circuit current when the electrical fault CC occurs in the section to be protected AB of the conductive element 7.

[0070] In certain embodiments, the main electrical protection element 6 has a breaking capacity lower than a short-circuit current value. Thus, the main electrical protection element 6 is not configured to interrupt an electrical connection between the power supply 4 and the upstream point A of the section to be protected AB. The main electrical protection element 6 only creates an electric arc 61 which will trigger pyrotechnic switches 1, 2. Since the main electrical protection element 6 is not designed to interrupt the conductive element 7, the main electrical protection element 6 has a reduced size, allowing for easier physical integration of the main electrical protection element 6 in an aircraft.

[0071] In the embodiment of [Fig.1], the main electrical protection element 6 is a fuse.

[0072] The electrical circuit 100 also includes a first pyrotechnic switch 1 equipped with a first initiating element 11 and a first mechanical breaking element 12 which is configured to perform an electrical break of the conductive element 7 between the power supply 4 and the upstream point A of the section to be protected AB, and a second pyrotechnic switch 2 equipped with a second initiating element 21 and a second mechanical breaking element 22 which is configured to perform an electrical break of the conductive element 7 between a downstream point B of the section to be protected AB and the electrical load 31.

[0073] The pyrotechnic switches 1,2 can be in a closed state, as on the Figures 1 to 4 and 7, in which they allow electric current to pass through the conductive element 7, or in an open state, as in Figures 5, 6 and 8, in which electric current can no longer pass through the conductive element 7. The closed state is the state of the pyrotechnic switches 1, 2 during the normal operation of the electrical circuit 100. The pyrotechnic switches 1, 2 are in an open state only when the electrical fault DC occurs.

[0074] The pyrotechnic switches 1, 2 will be described more precisely with reference to figures 7 and 8.

[0075] The pyrotechnic switches 1, 2 each comprise an initiating element 11, 21 and a mechanical cutting element 12, 22.

[0076] In the embodiment of [Fig.7], the initiating element 11,21 comprises at least one electrical resistance surrounded by a pyrotechnic powder or liquid.

[0077] The initiating element 11,21 is in a nominal state, as illustrated in [Fig. 7], as long as the electrical voltage across its terminals is less than a tripping voltage. The nominal state is the state of the initiating element 11,21 during the normal operation of the electrical circuit 100. The initiating element 11,21 is in a tripped state, as illustrated in [Fig. 8], when the voltage across its terminals has become greater than or equal to the tripping voltage for at least one instant, such as during the occurrence of a DC electrical fault. A certain duration, called the tripping response time, is required for the initiating element 11,21 to transition from the nominal state to the tripped state.

[0078] In some embodiments, the response time of a triggering of the first 11 and the second 21 initiating elements are identical.

[0079] In some embodiments, the trigger voltage of the first initiating element 11 is equal to the trigger voltage of the second initiating element 21.

[0080] Thus when the initiating element 11,21 receives a voltage greater than or equal to the triggering voltage at its terminals, the initiating element 11,21, here an electrical resistance, heats up, which activates the pyrotechnic powder or liquid.

[0081] The first initiating element 11 and the second initiating element 21 are each electrically positioned in parallel with the main electrical protection element 6.

[0082] In the embodiment illustrated in [Fig.1], the electrical circuit 100 includes a first adjusting resistor 13 positioned electrically in series with the first initiating element 11 and a second adjusting resistor 23 positioned electrically in series with the second initiating element 21.

[0083] The adjustment resistors 13, 23 allow limiting a value of the current flowing in the initiating element 11, 21.

[0084] The mechanical cutting element 12, 22 is a movable element configured to perform an electrical break of the conductive element 7. In the embodiment illustrated in figures 7, 8, the mechanical cutting element 12, 22 includes a sectioning piston.

[0085] When the mechanical cutting element 12, 22 is activated, as in [Fig.8], the sectioning piston, which is movable in translation, cuts or sections the conducting element 7. The sectioning piston can be activated by a detonation or deflagration of the initiating element 11, 21.

[0086] The mechanical switching element 12, 22 can be in a nominal state or in an actuated state. The nominal state, illustrated in Figures 1 to 3 and 7, is the state of the mechanical switching element 12, 22 during the normal operation of the electrical circuit 100. The mechanical switching element 12, 22 is in an actuated state, as illustrated in Figures 5, 6, and 8, when the initiating element 11, 21 has transitioned to a triggered state. A certain duration, called the mechanical response time, is required for the mechanical switching element 12, 22 to transition from the nominal state to the actuated state. The mechanical switching element 12, 22 interrupts the conductive element 7 at the position of the pyrotechnic switch 1, 2.As the first mechanical switching element 12 cuts the conductive element 7 between the power supply 4 and the upstream point A of the section to be protected AB, the first pyrotechnic switch 1 is positioned between the power supply 4 and the upstream point A of the section to be protected AB, and as the second mechanical switching element 22 cuts the conductive element 7 between the downstream point B of the section to be protected AB and the electrical load 31, the second pyrotechnic switch 2 is positioned between the downstream point B of the section to be protected AB and the electrical load B. The first switch 1 and the second switch 2 are mechanically positioned in series along the conductive element 7.This electrical positioning makes it possible to increase the breaking capacity of each pyrotechnic switch 1, 2 so that the first pyrotechnic switch 1 and the second pyrotechnic switch 2 can be sized with a working voltage corresponding to half the voltage of the electrical supply which is applied to the electrical load 31.

[0087] In some embodiments, the mechanical response time of at least one first 12 and at least one second 22 mechanical cutting elements are identical.

[0088] When the initiating element 11,21 is in the nominal state, the mechanical cutting element 12, 22 is also in the nominal state and the pyrotechnic switch 1, 2 is in the closed state.

[0089] When the initiating element 11,21 is in the triggered state, the mechanical cutting element 12, 22 is in the actuated state and the pyrotechnic switch 1, 2 is in the open state.

[0090] As described above, the pyrotechnic switches 1, 2 are positioned in the open state when the voltage across the initiating element 11, 21 has become greater than or equal to the triggering voltage.

[0091] The operation of pyrotechnic switches 1, 2 when an electrical fault occurs DC will be described with reference to figures 1 to 6.

[0092] Figure 1 illustrates normal operation of the electrical circuit 100 according to the invention, in which the power supply 4 supplies the electrical load 31. During normal operation, the switching element 5 is in a closed state so as to allow the electric current to pass through the conducting element 7. In addition, the first pyrotechnic switch 1 and the second pyrotechnic switch 2 are in a closed state, and the main protection element 6 is in an engaged state.

[0093] Fig. 2 illustrates the appearance of the electrical fault CC in the conductive element 7, and more specifically in the section to be protected AB of the conductive element 7.

[0094] The DC electrical fault causes an increase in the electric current flowing in the conductive element 7 so as to at least reach the value of the maximum electric current of the main electrical protection element 6 and to cause a switch to the tripped state of the main electrical protection element 6 as illustrated in [Fig.3].

[0095] The switching to the triggered state of the main electrical protection element 6 results in the formation of an electric arc 61 between its terminals as illustrated in [Fig.4].

[0096] The electric arc 61 causes a voltage across the terminals of the first initiating element 11 and the second initiating element 21, which are each electrically positioned in parallel with the main electrical protection element 6, greater than or equal to the tripping voltage of the first initiating element 11 and the second initiating element 21. Thus the first initiating element 11 and the second initiating element 21 go to the tripped state, causing the first 12 and second 22 mechanical breaking elements to go to the activated state, and therefore finally the two pyrotechnic switches 1, 2 to go to the open state, as illustrated in [Fig.5].

[0097] Finally, the first 1 and the second 2 pyrotechnic switches are therefore in the open state, as illustrated in [Fig. 6]. The AB section of the conductive element 7 is thus electrically separated from the electrical circuit 100, and the electrical fault CC is therefore also isolated. There is no longer any possibility of re-energizing the electrical fault CC by the electrical load 31, i.e., even in the event of a windmilling effect.

[0098] In certain embodiments, the response time of a tripping of at least one first 11 and at least one second 21 initiating elements is less than the mechanical response time of at least one first 12 and at least one second 22 mechanical breaking elements. Thus, when the electric arc 61 forms across the terminals of the main electrical protection element 6, even if the first initiating element 11 receives the tripping voltage slightly before the second Initiating element 21, the first mechanical switching element 12 only enters the activated state when the second initiating element 21 has received the tripping voltage. Thus, both initiating elements 11, 21 are tripped before either of the mechanical switching elements 12, 22 enters the activated state.

[0099] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0100] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Electrical circuit (100) for supplying at least one electrical load (31) of an aircraft, the electrical circuit (100) comprising at least one electrical power supply (4) electrically connected to the at least one electrical load (31) by means of at least one conductive element (7), and at least one main electrical protection element (6) positioned between the at least one electrical power supply (4) and an upstream point (A) of a section (AB) of the at least one conductive element (7) to be protected upon the occurrence of an electrical fault (CF), characterized in that the electrical circuit (100) comprises at least one first pyrotechnic switch (1) provided with at least one first initiating element (11) and at least one first mechanical breaking element (12) which is configured to effect an electrical break of the at least one conductive element (7) between the at least one electrical power supply (4) and the upstream point (A) of the section to be protected (AB),and at least one second pyrotechnic switch (2) equipped with at least one second initiating element (21) and at least one second mechanical breaking element (22) which is configured to effect an electrical break of at least one conductive element (7) between a downstream point (B) of the section to be protected (AB) and the electrical load (31), the first initiating element (11) and the second initiating element (21) each being electrically positioned in parallel with at least one main electrical protection element (6).

2. Electrical circuit (100) according to claim 1, wherein a response time of a triggering of at least one first (11) and at least one second (21) initiating elements is less than a mechanical response time of at least one first (12) and at least one second (22) mechanical breaking elements.

3. An electrical circuit (100) according to any one of the preceding claims, wherein at least one first initiating element (11) and / or at least one second initiating element (21) comprises at least one electrical resistor surrounded by a pyrotechnic powder or liquid

4. Electrical circuit (100) according to any one of the preceding claims, wherein at least one first mechanical switching element (12) and / or at least one second mechanical switching element (22) comprises a sectioning piston.

5. Electrical circuit (100) according to any one of the preceding claims, wherein at least one main electrical protection element (6) has a working voltage corresponding to half of the voltage of the electrical supply that is applied to the electrical load.

6. Electrical circuit (100) according to any one of the preceding claims, comprising at least a first adjusting resistor (13) electrically positioned in series with the first initiating element (11) and / or at least a second adjusting resistor (23) electrically positioned in series with the second initiating element (21).

7. Electrical circuit (100) according to any one of the preceding claims, comprising at least one distribution box equipped with at least one switching element (5).

8. Aircraft comprising an electrical load (31) powered by an electrical circuit (100) according to any one of the preceding claims.

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