EP1271091B1 - Pyrotechnic activation safety-system - Google Patents

Abstract

The pyrotechnic initiation circuit (IP) contains a reservoir of electrical energy (AI) connected to the positive poles (PP) of an igniter (FL) via two switches (I1,I3) in series. The negative poles are connected to a third switch (I2). The first verification circuit (V1) is connected to the first switch via a cutout circuit (FU). The second verification circuit (V2) is connected to the third switch and the analyzing and sequencing circuits are connected to the second switch and the cutout circuit. There are connections to circuits on board the aircraft carrying the missile (C1-C3).

Description

The present invention relates to a secure pyrotechnic activation system according to the preamble of claim 1. Such a system is known from the document WO 0131283 A . It applies in particular to the pyrotechnic initiation of propulsion systems and the priming of rockets, in the field for example ammunition carried under aircraft (missiles or bombs).

Depending on the context, the term "pyrotechnic activation" is a pyrotechnic initiation (ie a firing), or the initiation of an explosion. Today, the propulsion systems of airborne ammunition are initiated by one or more electrical orders issued by the aircraft, on command of the pilot. The initiation of the propulsion systems, ie the firing of the ignition chain, is instantaneous. There is sometimes a state of security of the ammunition, state in which the propulsion systems can not be initiated. This state of safety makes it possible to avoid accidents during the storage of the munitions, during their handling, during their disassembly ...

• la réalisation de tels dispositifs est complexe par rapport à des dispositifs électroniques ;
• il n'est pas possible de tester facilement le bon fonctionnement du système d'initiation sans le rendre réellement actif.

A known solution is to misalign the pyrotechnic initiation system and the ignition system. When the initiation system is misaligned, it can not initiate even accidentally, the ignition system. A mechanical force is used to make the weapon active. This mechanical force makes it possible to align the pyrotechnic initiation system with the ignition chain. For example, the pulling force exerted by a wire called "safety release" (SL), pulled by the pilot, is used. In case of accidental pulling of the wire SL (collision with a bird for example), such a system becomes dangerous because it can not return to a state of security. This problem is related to the use of a mechanical force to lift the security. The use of a mechanical force has other disadvantages:

• the realization of such devices is complex compared to electronic devices;
• it is not possible to easily test the proper functioning of the initiation system without actually making it active.

In addition, to ensure the safety of aircraft and pilots, initiation should take place away from the aircraft. Then there is the problem of energy autonomy, after the separation of the weapon (missile or bomb) from the plane.

An object of the invention is to solve the aforementioned problems, and in particular to have a secure pyrotechnic activation system that does not require the use of a mechanical force for its activation, and can be autonomous after its release.

For this purpose the invention relates to a pyrotechnic activation system of a system intended to be released from a carrier according to claim 1.

The main advantages of the invention are that it enables the remote system of the carrier to be activated, that it is simple to integrate and to achieve, that it is reliable, safe and economical.

• les figures 1, 2 et 3 sont des exemples de munitions dans lesquelles l'invention peut être utilisée ;
• la figure 4 est schéma fonctionnel sur lequel est illustré un exemple de système d'initiation pyrotechnique selon l'invention ;
• la figure 5 une vue d'un exemple d'assemblage du système d'initiation pyrotechnique représenté sur la figure 4 sur un système propulsif tel que celui de la bombe représentée sur la figure 3,
• la figure 6 est une vue de détail de la figure 5,
• les figures 7, 8, 9 sont différentes vues du système d'initiation représenté sur la figure 4.

The present invention will be better understood on reading the detailed description of an embodiment, taken by way of nonlimiting example and illustrated by the appended drawings, in which:

• Figures 1, 2 and 3 are examples of ammunition in which the invention may be used;
• FIG. 4 is a block diagram on which is illustrated an example of a pyrotechnic initiation system according to the invention;
• FIG. 5 is a view of an assembly example of the pyrotechnic initiation system shown in FIG. 4 on a propulsion system such as that of the bomb shown in FIG. 3,
• FIG. 6 is a detail view of FIG. 5,
• Figures 7, 8, 9 are different views of the initiation system shown in Figure 4.

The invention applies in particular to the initiation of thrusters and the priming of explosive systems to be dropped from a carrier. These systems can be ammunition such as bombs or missiles. In the following presentation, we will take the example of a bomb carried by an airplane. Of course, the invention applies to any type of system to be dropped, the system is not necessarily a bomb, the carrier is not necessarily an aircraft.

The bombs can be grouped into three families: the smooth bombs, the bombs with guide kit (also called "kite bombs"), and the bombs with range augmentation kit.

• un corps de bombe CDB, contenant une composition pyrotechnique appelée chargement explosif (non représenté), ce corps de bombe CDB étant placé en partie avant de la bombe M1,
• une fusée FUS, contenue dans le coeur du corps de bombe CDB, destinée à amorcer le chargement explosif,
• un empennage lisse EMP, placé derrière le corps de bombe, c'est à dire en partie arrière de la bombe, assurant par aérodynamisme un guidage rudimentaire de la bombe M1.

With reference to FIG. 1, an example of a smooth bomb M1 is described. This M1 bomb mainly includes:

• a CDB bomb body, containing a pyrotechnic composition called an explosive charge (not shown), this CBD bomb body being placed in front of the M1 bomb,
• a FUS rocket, contained in the core of the CBD bomb body, intended to initiate the explosive charge,
• a smooth tail emp, placed behind the bomb body, ie in the rear part of the bomb, ensuring aerodynamically a rudimentary guidance of the bomb M1.

The FUS rocket comprises a pyrotechnic priming composition (not shown). This pyrotechnic priming composition is more simply called a primer. To prime the explosive charge, this primer detonates, resulting in detonation of the explosive charge.

With reference to FIG. 2, an example of a kitten bomb M2 is described. This M2 bomb mainly includes a CBD bomb body, a FUS rocket, and a KGA guide kit, KGR. This guide kit consists of two parts, one at the front KGA and the other at the rear KGR of the bomb. GV control surfaces are placed on this kit. The guide kit replaces the empennage of the smooth bombs. It makes it possible to steer the M2 bomb more efficiently by means of the GV control surfaces and to increase its range.

With reference to FIG. 3, an example of an M3 bomb with a range augmentation kit is described. This M3 bomb mainly includes a CDB bomb body, a FUS rocket, a KGA guide kit, KGR, and a PRO, IP propulsion system. The propulsion system and guide kit constitute the range increase kit. The propulsion system PRO, IP can be placed on the rear of the M3 bomb in the KGR rear guide kit. It includes a PRO booster and an IP pyrotechnic initiation system. PRO booster comprises pyrotechnic compositions (not shown).

The pyrotechnic initiation system IP comprises a pyrotechnic initiation composition. This pyrotechnic initiation composition is more simply called an igniter. The igniter makes it possible to bring into combustion mode a first pyrotechnic propellant composition.

This first pyrotechnic propellant composition can in turn bring into combustion regime other pyrotechnic chain compositions. These first pyrotechnic compositions constitute what is called the ignition system of the propellant. The ignition system brings into combustion a last pyrotechnic composition of the propellant. The combustion of this last pyrotechnic composition, called propellant pyrotechnic composition, propels the bomb.

Compared to the two families of bombs without propulsion system, the propulsion system makes it possible to further increase the range of the bombs, while keeping a good precision thanks to the guide kit.

According to Figures 1, 2 and 3, according to a preferred embodiment of the invention, a measuring device SA is placed in the upper part of the bomb body. This measuring device makes it possible to measure the environment outside the bomb. Before being dropped, the bomb M1, M2 or M3 can be stowed to the aircraft by square brackets F1, F2. The FUS rocket being placed in the heart of the CBD bomb body, a gutter G1 can connect the measuring device SA and the rocket FUS. An electric cable (not shown) placed in this gutter makes it possible to connect the measuring device SA and the rocket FUS.

According to FIG. 3, according to an advantageous embodiment, a link connects the IP pyrotechnic initiation system with the FUS rocket. This connection can be made by an electric cable placed in a second gutter G2. Through this link, information and / or commands can be issued from the FUS rocket to the IP pyrotechnic initiation system. It is thus possible to save the electronic security management components performing common functions between the FUS rocket and the IP pyrotechnic initiation system. Measurements made by the measuring device SA can also be used by using a serial type connection, which makes assembly and disassembly of the bomb easier.

• un capteur de traction du fil SL, destiné à mesurer la traction du fil SL,
• un capteur de pylône, destiné à détecter la présence ou non de l'avion,
• un capteur de la vitesse du vent, destiné à mesurer la vitesse du vent.

The measuring device SA can comprise:

• a traction sensor of the wire SL, intended to measure the traction of the wire SL,
• a pylon sensor, intended to detect the presence or absence of the aircraft,
• a wind speed sensor, designed to measure the wind speed.

The traction sensor SL may be constituted by a magnet mechanically connected to the wire SL, said magnet being placed in the middle of a coil. Pulling the wire causes the magnet to move in the coil, creating a current.

The tower sensor comprises for example a valve. This valve is placed on the top of the bomb, and is in contact with the plane when the bomb is under the plane. The plane exerts on the valve a force which tends to close it. The sensor may further comprise a spring placed under the valve, which tends to open the valve in the absence of resistance. Thus, the flap is open when the bomb is no longer under the plane, and closed when the bomb is under the plane. An electrical circuit of the tower sensor can generate a signal depending on the position of the valve, and thus to detect the presence of the aircraft.

The wind speed sensor may be a wind turbine, which generates an alternating signal whose frequency is proportional to the speed of rotation of the wind turbine.

According to FIG. 4, in which is illustrated a preferred embodiment, the IP pyrotechnic initiation system comprises an igniter FL. This FL igniter is initially uninitiated. When it is initiated, it enters combustion mode. The FL igniter is aligned with the propeller ignition system. In other words, no check valve or mechanical system makes an obstacle between the ignition chain and the igniter, so that when the igniter is initiated, it puts into combustion mode the ignition system of the ignition system. propellant. For safety reasons, the FL igniter is insensitive. Only electrical energy above a certain threshold can initiate the FL igniter. Noise currents or electromagnetic disturbances can not initiate the FL igniter. For example, a 1A / 1W igniter is used. A current of 1A with a power of 1W for 5 minutes is not sufficient to initiate this igniter. A high energy electrical pulse is used to initiate this igniter.

The IP pyrotechnic initiation system comprises a reserve of electrical energy A1. This reserve of electrical energy A1 is initially not activated. In this state, this reserve delivers by energy. The energy contained in this reserve is preserved. This reserve Al is intended to be activated to deliver energy. Advantageously, this energy reserve is a thermal battery.

An electrical circuit including safety switches connects the thermal stack Al and the igniter FL. For example three safety switches I1, 12, 13 are connected in series on this circuit. They can be controlled respectively by safety management means V1, V2, V3. These switches open the electrical circuit. In other words, the switches I1, 12, 13 allow or prevent the thermal battery Al from delivering a supply to the igniter FL. When the electrical circuit is closed and the thermal battery Al is activated, it delivers enough energy to initiate the igniter FL.

Advantageously, the switches I1, 12, 13 are of different technologies to avoid common failure modes. The switch I1 may be an electronic transistor, the switch 12 may be an electromechanical relay, the switch 13 may be an electronic transistor of technology different from I1.

Advantageously, the switches I1, I2, and 13 are placed on either side of the positive poles PP and negative PN of the igniter FL. For example, the switches I1 and 12 are on the positive pole side PP, and the switch 13 on the negative pole side PN. This makes the circuit more reliable.

Advantageously, a selector 14 with manual control MA is placed in the electrical circuit connecting the igniter FL and the thermal battery AI. This selector makes it possible to inhibit the power supply of the FL igniter manually. It has a first "security" position and a second "non-security" position. In its first safety position, it opens the electrical circuit between the negative pole PN of the igniter FL and the mass, and at the same time closes a connection between the positive pole PP of the igniter FL and the mass. In this way, in this first position, the selector opens the supply circuit of the igniter FL on the one hand, and bypasses the igniter FL on the other hand. In other words, the first position ("safety") inhibits the FL igniter. In its second position ("out of safety"), this selector no longer inhibits the FL igniter. Thus, the weapon can be placed manually in a safe position for handling, for example.

Before the release, the safety management means V1, V2, V3 can be electrically powered (power supply circuit not shown) by an external power supply AE. This external power supply AE can come from the plane for example. A connector C1 of the pyrotechnic initiation system can connect the external power supply AE to the thermal battery Al for example. After the release, the thermal battery Al is activated, thus creating a potential difference at its terminals. It then delivers a power supply substituting for that delivered by the aircraft.

• émission d'une intention de tir, telle que la traction d'un fil SL ou l'émission d'un message codé,
• largage de la bombe de l'avion,
• éloignement de la bombe par rapport à l'avion.

The safety management means V1, V2, V3 make it possible to check a given operational release sequence. The verification of an operational sequence confirms a shooting intention. A nominal operational sequence may comprise, for example, the following steps:

• issuing a shooting intention, such as pulling a wire SL or sending a coded message,
• dropping the bomb from the plane,
• distance from the bomb relative to the aircraft.

This sequence does not take place in a nominal way in the event of an accident. There are two examples. A first example is an accidental pull of the SL wire (collision with a bird). In this example, the issuance of a fire intention will not be followed by the dropping of the bomb. A second example is the accidental release of the bomb (bomb is badly secured to the wearer). In this example, the release will not be preceded by a broadcast of a shooting intent. In these two examples, the security management means V1, V2, V3 detect a non-nominal sequence. They inhibit the initiation of the FL igniter. In other words, the safety management means V1, V2, V3 hold at least one of the switches I1, I2, I3 open so as to prevent the thermal battery Al from delivering a supply to the igniter FL.

When the safety management means V1, V2, V3 detect a nominal operational sequence, they control the closing of the switches I1, 12, I3. In other words, they allow the heat stack Al to supply a supply to the igniter FL. The igniter FL is then initiated which makes the propeller ignition chain enter the combustion mode.

1. (a) un premier moyen de vérification d'environnement V1, pour émettre le premier signal de commande après la détection d'un premier environnement de largage E1, ledit signal de commande pouvant activer la réserve d'énergie Al ;
2. (b) un second moyen de vérification d'environnement V2, pour émettre un second signal de commande après la détection d'un second environnement de largage E2, le second environnement étant différent du premier E1, les premier et second signaux de commande agissant sur un ou plusieurs des interrupteurs de sécurité I1, 12 de manière à initier l'inflammateur FL.

According to an advantageous embodiment, the security management means comprise:

1. (a) first environment verification means V1, for outputting the first control signal after the detection of a first drop environment E1, said control signal being able to activate the energy reserve A1;
2. (b) second environment verification means V2, for transmitting a second control signal after detecting a second drop environment E2, the second environment being different from the first E1, the first and second control signals operating on one or more of the safety switches I1, 12 so as to initiate the FL igniter.

The first drop environment E1 can be, for example, the traction of the wire SL, the absence of contact between the airplane and the bomb, the wind speed outside the bomb, a coded message coming from the airplane ... take for example the traction of the wire SL. The measuring device SA can be electrically connected by a connection C2 to the first verification means V1. This connection C2 makes it possible to dispose of the electrical signals generated by the traction sensor of the wire SL. The first drop environment E1 is thus converted into electrical signals. The first verification means V1 can control the closure of the switch I1 if this first drop environment E1 is detected, that is to say if the traction of the wire SL is detected by the traction sensor.

As soon as this first drop environment E1 is detected by the first verification means V1, a control signal can be sent to the thermal stack Al to activate it.

The second drop environment E2 may be for example the wind speed outside the bomb. This second drop environment E2 is different from the first drop environment E1, so as to avoid initiating the pyrotechnic initiation system following an accident (collision with a bird). The measuring device SA can be electrically connected by a connection C3 to the second verification means V2. This connection C3 makes it possible to dispose of the electrical signals generated by the wind turbine. The second drop environment E2 is thus converted into electrical signals. The second verification means V2 can control the closing of the switch 12 if this second drop environment is detected.

Advantageously, the verification means V1, V2 use two independent channels (components dedicated to each function) to act on the safety switches I1, I2.

Advantageously, the verification means V1, V2 comprise timing means, arranged to transmit the first and second control signals after determined delays. Thus, the first control signal is transmitted to the switch I1 after a delay T1, and the second control signal is transmitted to the switch 12 after a delay T2. These T1 and T2 delays protect the pilots in the event of abnormal operation of the propulsion system for example (ignition explosion).

Advantageously, the delay means are of different technologies. The first delay means can be quartz, the second delay means can be a clock RC (resistance clock and capacitance).

According to an advantageous embodiment, the security management means further comprise a sequencing analysis means V3 for transmitting a third control signal if the first and second control signals are received in a determined order in a window. determined time, the third control signal acting on one or more of the safety switches 13 so as to initiate the igniter FL.

The sequencing analysis means V3 receives the control signals from the first and second verification means V1, V2. If these control signals are received in the order and in a given time window, the analysis means of the sequencing V3 can control the closing of the switch I3. The three switches I1, 12, and 13 are in the closed position. If the selector 14 is in its second position ("out of safety"), the thermal battery Al initiates the igniter FL. It enters the combustion regime, which brings the ignition system and the propellant pyrotechnic composition into the combustion regime.

If the two environments E1, E2 are not detected in the order and in a given window, the switch 13 remains open. This corresponds to a non-nominal sequence.

According to an advantageous embodiment, the initiation system further comprises sterilization means FU for irreversibly preventing the reserve of electrical energy A1 from delivering a supply to the igniter FL after a non-nominal sequence. These FU sterilization means may be of the fuse type. According to a preferred embodiment, this fuse is placed on a control circuit of one of the switches I1, I2 or 13, so as to leave this switch open. For example the fuse can be placed on the control circuit of the switch I1. This is preferable to place a fuse directly on the circuit connecting the thermal stack Al to the igniter FL because the energy needed to melt it would be very important (the igniter FL being insensitive, a strong current must flow on this circuit ).

• après un retard fixe suivant l'arrivée du premier signal de commande, ce retard fixe étant supérieur au délai normal de transmission du second signal de commande et d'initiation pyrotechnique, ou
• si le moyen d'analyse du séquencement V3 détecte une séquence non nominale.

The sterilization (in this example, it is to melt the fuse FU), can intervene for example:

• after a fixed delay following the arrival of the first control signal, this fixed delay being greater than the normal transmission delay of the second control and pyrotechnic initiation signal, or
• if the sequencing analysis means V3 detects a non-nominal sequence.

This sterilization allows, in case of non-nominal operational sequence, the return on the basis of the bomb in a state where the igniter FL can not be initiated electrically.

Referring to Figure 5, and the detail view Figure 6, there is described an assembly example of the IP pyrotechnic initiation system on a propulsion system such as that of the M3 ammunition (Figure 3). The thruster PRO comprises a cylindrical cavity in which are located the ignition chain CHA and the propellant pyrotechnic composition CPP. The pyrotechnic propellant composition CPP may be a concentric propellant ring with the axis AX of the cavity for example. The outer wall of the cavity is traversed in its lower part INF (that is to say on the rear side of the bomb M3) by a nozzle TUY. The nozzle makes it possible to guide the gases resulting from the combustion of the pyrotechnic propellant composition CPP from the inside of the cavity to the outside EX. The TUY nozzle has an axis of rotation symmetry coincident with the axis AX of the cavity. The IP pyrotechnic initiation system can be fixed to the lower part INF of the cavity, so as to be accessible from the outside without the need to disassemble other elements of the bomb.

According to an advantageous embodiment, the igniter FL (FIG. 6) is housed in a structure composed of a KT material having a very high coefficient of thermal attenuation. This structure can have a cylindrical shape for example. The assembly constituted by this structure and by the igniter FL is called a pyrotechnic rod CAP. This pyrotechnic rod CAP is housed in the PRO propeller cavity. The propeller cavity PRO itself has an ISO thermal protection. Thus, in the event of a fire, this CAP can protect the FL igniter by limiting heat transfer by conduction through the pyrotechnic initiation system. This delays the self-ignition of the igniter FL in case of fire.

With reference to FIGS. 7, 8, 9, the BOI box of the IP pyrotechnic initiation system is a conductive material. Thus, this housing constitutes a Faraday cage protecting the electronic components of the IP pyrotechnic initiation system. These electronic components, such as security management means V1, V2, V3, can be assembled on an electronic card CE.

The BOI box may comprise fixing holes T1, T2, T3, T4, T5, T6 intended to be placed opposite threaded holes of the PRO propeller cavity. The threaded holes (not shown) of the cavity may be made in bosses of the lower wall INF of the cavity.

An NC connector can group connections C1, C2, C3. Advantageously, this connector is accessible from the outside once the pyrotechnic initiation system IP fixed on the cavity of the propeller PRO.

Referring to Figure 9. At the end of life, the initiation system can easily be removed from the bomb (the initiation system is fixed on the thruster by means of screws). Preferably, the thermal stack Al and the pyrotechnic rod CAP are fixed by means of nuts ECR1, ECR2 BOI box. In this way, after removing a COU cover IP pyrotechnic initiation system, the thermal battery Al and the pyrotechnic rod CAP can easily be removed from the BOI box. All that is required is to remove the SD seals connecting the thermal battery Al and the pyrotechnic CAP (FL igniter) to the electronic card CE on the one hand, and to unscrew the nuts ECR1, ECR2 on the other hand.

• réaliser des contrôles fonctionnels unitaires d'acceptation en environnements (climatiques, vibratoires) avec intégration de la canne pyrotechnique,
• réaliser des contrôles fonctionnels durant la vie de la bombe.

The pyrotechnic initiation system IP according to the invention can easily be tested functionally in the inert state, that is to say once the pyrotechnic rod dismounted. This allows:

• carry out unitary acceptance functional checks in environments (climatic, vibratory) with integration of the pyrotechnic rod,
• carry out functional checks during the life of the bomb.

Functional tests can be performed by connecting a control device to the NC connector. Preferably, in test mode, the heat stack Al and the sterilization means FU are inhibited.

Of course, the invention is not limited to this exemplary implementation, described by way of illustration. In particular, the reserve of electric energy Al is not necessarily a thermal battery. It is possible to use instead capacities loaded by the power of the aircraft.

The invention also applies to rockets. The FL igniter is then replaced by a primer. In general, the igniter of a propellant and the primer of a rocket are pyrotechnic compositions. They are activated, ie initiated for the igniter, and initiated for the rocket, by an electrical pulse.

The invention applies of course to any type of system to be dropped. For example, missiles dropped from a submarine or an aircraft carrier can be cited.

Claims (8)

1. System for the pyrotechnic activation of a system intended to be released from a carrier, comprising at least:

   (a) a pyrotechnic composition (FL);

   (b) a reserve of electrical power (AI) able to deliver a sufficient electrical power supply to activate the pyrotechnic composition (FL) when the said reserve (AI) is activated, the said reserve being activated after release;

   (c) several safety switches (I1, I2, I3) arranged in such a way as to activate or not activate the pyrotechnic composition (FL) by allowing or preventing the delivery of power by the reserve of electrical power (AI) to the said pyrotechnic composition (FL);

   (d) safety management means (V1, V2, V3), powered by the reserve of electrical power (AI) after release, to verify a determined operational release sequence and to control the safety switch or switches (I1, I2, I3) in such a way as to activate the pyrotechnic composition if the operational release sequence is nominal,

   characterized in that the safety management means (V1, V2, V3) comprise:

   - means (V1, V2) for checking that determined environment conditions are satisfied and for generating control signals for controlling some of the safety switches (I1, I2) so as to activate the pyrotechnic composition when the said environment conditions are satisfied, and

   - a means (V3) of analysing the pyrotechnic composition activation sequence, the said means being able to receive the control signals generated by the other safety management means (V1, V2) and, if the corresponding control signals are received in a determined order and within a determined time slot, to generate a control signal acting on one of the safety switches (13) so as to validate activation of the pyrotechnic composition (FL).
2. System according to Claim 1, characterized in that the safety management means comprise at least:

   (a) a first environment verifying means (V1) for emitting the first control signal after a first release environment (E1) has been detected, the said control signal being able to activate the reserve of power (A1);

   (b) a second environment verifying means (V2) for emitting a second control signal once a second release environment (E2) has been detected, the second environment being different from the first (E1), the first and second control signals acting on one or more of the safety switches (I1, I2) in such a way as to activate the pyrotechnic composition (FL).
3. System according to Claim 2, characterized in that the safety management means further comprise time-delay means designed to transmit the first and second control signals after determined delays.
4. System according to one of the preceding claims, characterized in that it comprises sterilizing means (FU) for irreversibly preventing the reserve of electrical power (AI) from delivering power to the pyrotechnic composition (FL) after a non-nominal sequence.
5. System according to any one of the preceding claims, characterized in that the pyrotechnic composition (FL) is placed in a tube (CAP) of low thermal conductivity.
6. System according to any one of the preceding claims, characterized in that the various switches (I1, 12, I3) used employ different technologies in order to avoid common failure modes.
7. System according to any one of the preceding claims, characterized in that the switches are placed on each side of the positive (PP) and negative (PN) terminals of the pyrotechnic composition (FL).
8. System according to any one of the preceding claims, characterized in that it comprises a manually operated (MA) selector (14) allowing the electrical power supply to the pyrotechnic composition (FL) to be inhibited manually.

Images