Fuse device, power supply and electrical arrangement comprising a fuse device of this kind

Abstract

The invention relates to a fuse device (10) for overload protection of electronic components with an improved faster tripping characteristic. For this purpose, the fuse device has a chain of fuse paths (18), wherein the chain has a first fuse path (20) with a first fuse element (22) and a last fuse path (24) with a last fuse element (26), wherein the last fuse path (24) has a last transverse element (28) connected electrically in series upstream of the last fuse element (26), wherein the last fuse path (24) is connected electrically in parallel with a previous fuse element (22, 36A-E) in the chain of fuse paths. The invention also discloses a non-linear bypass element (32) which is connected in series with the last fuse element (26) and further improves the tripping characteristic.

Description

[0001] Title: Safety device, power supply and electrical arrangement with such a safety device

[0002] Description

[0003] The invention relates to an electronic safety device for overload protection of electronic components. The invention also relates to a power supply and an electrical arrangement, each comprising such a safety device.

[0004] Fuses are known from the prior art for protecting electronic components in DC and AC systems. Fuses made of a metal wire or metal strip are used for this purpose; they melt in the event of an overcurrent. A sufficient overcurrent is required to ensure that the fuses melt. The ratio between the operating current in a tripping state and the operating current in an operating state is typically in the range of 10:1. The operating current at which the fuse melts is referred to as the minimum tripping current or threshold current.

[0005] For the grid integration of renewable energy sources based on power electronics for battery-supported storage applications, safety devices are required that require a low minimum tripping current or have a low ratio. For example, redox flow batteries can be used as storage applications. Due to their high impedance, they provide an operating current in the event of a short circuit that is only 2:1 to the operating current of the normal application.

[0006] For such applications in connection with DC systems, safety devices with a pyroelectric switch are known. These interrupt a current path when a certain operating current is present. An external circuit is required for the interruption, which incurs additional costs and effort.

[0007] The invention is therefore based on the object of providing a safety device with a low minimum tripping current and / or a low ratio between an operating current in the operating state and a minimum tripping current, wherein the disadvantages of the prior art are eliminated.

[0008] The object is achieved by a safety device having the features of claim 1. The invention is directed to a safety device comprising: an input contact and an output contact, a current path extending between the input contact and the output contact and having a chain of safety paths, the chain of safety paths having a plurality of safety elements. The chain of safety paths has a first safety path with a first safety element and a last safety path with a last safety element, wherein the safety elements are each designed to be able to change from a through state to an open state when a respective threshold current is exceeded.The last fuse path has a last transversal element electrically connected in series upstream of the last fuse element, wherein the last fuse path is electrically connected in parallel to a previous fuse element in the chain of fuse paths.

[0009] A fuse element can be a simple fuse. This refers to an overcurrent protection device that interrupts the circuit by melting a fusible element when the current exceeds a predetermined nominal value for a specified time. This process is also called "fuse blowing." The specified time can depend on the actual current. For example, a fuse will blow significantly more slowly at a current only slightly above the predetermined nominal value, e.g., at 1.5 times the nominal value, e.g., in the range of 100 s to 1,000 s, than at a significantly higher current, e.g., at 5 times the nominal value, in which case it will blow in the range of 1 s to 2 s.

[0010] The fuse element can also be an alternative overcurrent protection device, such as:

[0011] - Electronic fuse,

[0012] - Self-resetting fuse, e.g. a PTC thermistor or a PTC fuse

[0013] - a form of load-dependent resistance

[0014] - Circuit breaker.

[0015] All these overcurrent protection devices have the advantage of being readily available, but the disadvantage that they all exhibit a previously described dependence of the tripping time on the tripping current.

[0016] Consequently, a simple parallel arrangement of several such securing elements would not achieve the desired result.

[0017] Only with the arrangement described in claim 1 is this disadvantage overcome.

[0018] In one aspect, the fuse device is designed such that in an operating state of the fuse device the input contact and the output contact are electrically connected to one another with low resistance by means of the current path, wherein in the operating state an operating current which is less than the threshold current of the last fuse element flows via the last fuse element such that the last fuse element remains in the through state. In a transition state of the fuse device which is to be distinguished from the operating state, an operating current which is greater than the threshold current of the last fuse element flows via the last fuse element such that the last fuse element changes to the interrupted state. The fuse device changes from the operating state to the transition state depending on a voltage drop across the last transversal element and / or a current flowing via the last transversal element.Low resistance means resistance values ​​that are < 0.1 Q, preferably < 0.01 Q.

[0019] Accordingly, a fuse device with a low minimum tripping current is provided. The asymmetrical design of the chain of fuse paths also allows a further reduction of the minimum tripping current. The same applies to the ratio between the operating current in the tripped state and in the operating state. Accordingly, the fuse device is particularly well suited for DC and / or AC applications in which the operating current does not increase by a factor of 10 compared to the normal operating state. Furthermore, this is accompanied by a fast tripping characteristic.

[0020] It is advantageous if the safety device is designed in such a way that in the operating state the current present at the safety device is distributed to all the safety elements evenly or in a cascade manner with a predefined gradient falling along the chain of the safety paths.

[0021] In one aspect, several, in particular all, of the safety elements connected upstream of the last safety element have one or more of the following properties:

[0022] - the same design,

[0023] - the same resistance in the conducting state,

[0024] - the same triggering characteristics.

[0025] In this way, the task can be solved advantageously.

[0026] In one aspect, the last fuse element has a resistance that differs from one of the other fuse elements by a factor of 0.618. This reciprocal is known from the golden ratio, for which:

[0027] 1.6180 0.6180

[0028] In one aspect, several, in particular all, of the fuse paths following the first fuse path comprise a series circuit comprising a transverse element and a fuse element. This advantageously achieves the stated object.

[0029] In one aspect, the first securing path does not have a transverse element, but preferably only one securing element. This advantageously solves the stated problem.

[0030] In one aspect, several, in particular all, fuse paths following the first fuse path are each electrically connected in parallel with the fuse element of the preceding fuse path.

[0031] In one aspect, several, in particular all, resistance values ​​of the fuse elements of the fuse paths upstream of the last fuse path are the same. This advantageously solves the aforementioned problem.

[0032] In one aspect, the resistance value of the last fuse element is smaller than the resistance value of one, or preferably of all, upstream fuse elements and / or smaller than the resistance value of one, or preferably of all, transversal elements. The resistance value of the last fuse element is in particular in the range of 0.5 to 0.7 times, preferably in the range of 0.6 to 0.64, particularly preferably in the range of 0.61 to 0.625 the resistance value of the other fuse elements 22, 36A-36C and / or the transversal elements 38A-38C, 28. In one aspect, the resistance values ​​of the transversal elements of the fuse paths following the first fuse path and upstream of the last fuse path are all the same size and, in particular, also the same size as the resistance values ​​of the respective fuse elements within a fuse path.

[0033] Using the aspects described above, a chain reaction can be triggered in which the last fuse element triggers first, and all other fuse elements trigger in the sequence from the last to the first. At the same time, many identical fuse elements can be used. At the same time, the spacing between the fuse elements can be chosen to be the same, as this significantly determines the resistance value of the transverse elements.

[0034] For the reliable production of such a safety device, it can be important to be able to use as many identical components as possible and a mechanical arrangement that is as reproducible as possible.

[0035] In one aspect, the safety device has a bypass path. This advantageously achieves the stated object.

[0036] In one aspect, the bypass path comprises a bypass element. This advantageously solves the aforementioned problem.

[0037] In one aspect, the bypass element has a non-linearity with respect to one or more of the following relationships:

[0038] - current to voltage,

[0039] - resistance to voltage,

[0040] - resistance to current,

[0041] - Resistance to temperature .

[0042] This advantageously solves the aforementioned problem. In one aspect, the bypass element has a semiconductor structure. This allows nonlinearities to be manufactured very cost-effectively in large series. Preferably, the semiconductor structure has a pn junction. Such a pn junction, as known from diodes or transistors, can be manufactured very cost-effectively in large series with high reproducibility.

[0043] In one aspect, the bypass path is connected in series with the last safety element. This allows the aforementioned task to be advantageously solved.

[0044] In one aspect, the bypass path is connected in parallel to several, in particular all, safety paths upstream of the last safety element. This advantageously solves the aforementioned problem.

[0045] In one aspect, the bypass path is connected in parallel to a series circuit of several, in particular all, safety paths connected upstream of the last safety element. This advantageously solves the aforementioned problem.

[0046] The bypass element preferably has a non-linear current-voltage characteristic. The bypass element is preferably designed to be able to switch from a blocking state to a conducting state. Due to the bypass path, a current can be directed to a fuse path in the chain of fuse paths, so that the current at the fuse device is no longer distributed asymmetrically across all fuse elements. Due to the asymmetric distribution, a fuse element is triggered which would not trigger with a symmetrical distribution.

[0047] A further advantageous aspect of the device provides that the bypass element is designed to have a non-linear current increase, in particular a non-linearly accelerated current increase, as a function of a voltage drop across the last transversal element. Accordingly, additional resistors are provided in the safety device which, in the event of an overcurrent, cause the state of the safety device to change from the operating state to the transition state. The bypass element is preferably designed such that it changes from the blocking state to the conducting state as a function of a voltage drop across the last transversal element. Although the provision of additional resistors increases the losses in the operating state, surprisingly the state change can be implemented without an additional circuit or peripherals. The bypass element is preferably connected in parallel to the transversal element orto the transversal elements. If several transversal elements are provided, the safety device preferably changes from the operating state to the transition state as a function of a voltage drop across all transversal elements and / or a current flowing across all transversal elements.

[0048] An advantageous aspect of the device provides that the bypass element has its non-linearity of the current-voltage characteristic in a voltage range in which the safety device reaches a tripping current at which the safety device changes from the operating state to the transition state and the bypass element is preferably designed to change from the blocking state to the conducting state in the voltage range. Accordingly, the bypass element can be specifically adjusted to the application of the safety device. Depending on the voltage range in which tripping is to occur, the safety device can change from the operating state to the transition state. This is particularly advantageous if a low minimum tripping current or a low ratio between the operating current and the tripping current is to be provided.An advantageous aspect of the device provides that the bypass path is connected at one end to the input contact, and the bypass path is connected at its other end to the last fuse path between the last transverse element and the last fuse element. Accordingly, the current conductable by the asymmetrical structure can be specifically directed to the last fuse element.

[0049] An advantageous aspect of the device provides that the bypass element is designed to conduct a current via the bypass path to the last fuse element in the transition state, so that the operating current at the last fuse element exceeds the threshold current of the last fuse element and the last fuse element changes from the conduction state to the interruption state. Consequently, a rapid tripping characteristic can be achieved by conducting a larger current specifically to the last fuse element.

[0050] An advantageous aspect of the device provides that the last transversal element is designed or all transversal elements are designed to reduce its / their resistance when the voltage drop across the last transversal element or across all transversal elements rises above a threshold value and / or the current flowing across the last transversal element or across all transversal elements rises above a threshold value. This represents an alternative embodiment for the targeted supply of current to the last fuse element when an electrical variable, such as a tripping current and / or a tripping voltage, is reached. It is conceivable to provide both a bypass path with a bypass element and a transversal element that reduces the resistance. Accordingly, a faster tripping characteristic can also be provided.

[0051] An advantageous aspect of the device provides that the safety device is designed such that, when the safety device is triggered, all safety elements are in the interrupted state, and the input contact and the output contact are not electrically connected via the current path. In the triggered state, the electrical connection between the input contact and the output contact is preferably completely interrupted. Accordingly, the downstream components are protected, and the overcurrent is not passed on.

[0052] An advantageous aspect of the device provides that in the chain of fuse paths between the first fuse path and the last fuse path there is provided a further fuse path with a further fuse element and a further transversal element electrically connected in series upstream of the further fuse element, wherein the further fuse path is electrically connected in parallel to a fuse element preceding it in the chain of fuse paths and / or wherein the transversal elements are electrically connected in series. By providing further fuse paths it is possible to achieve fuse devices with any desired tripping characteristics. Preferably as many identical parts as possible are used. Furthermore, large currents can be protected in this way with small fuse elements. Preferably all transversal elements are electrically connected in parallel to the bypass element.

[0053] An advantageous aspect of the device provides that the threshold current of the last fuse element is lower than the threshold current of the previous fuse element in the chain of fuse paths. This allows the tripping characteristic to be further accelerated. Accordingly, the last fuse element trips first in the event of an overcurrent. In the operating state, the upstream transversal elements ensure that the operating current at the last fuse element remains below the threshold current of the last fuse element.

[0054] An advantageous aspect of the device provides that the respective threshold current of the fuse elements decreases with each additional fuse element in the chain of fuse paths. Accordingly, a chain reaction can be triggered after the last fuse element switches to the interrupted state, which further accelerates the tripping characteristic.

[0055] An advantageous aspect of the device provides that the bypass element has a non-linear, voltage-dependent conductivity and / or is designed as a passive component, preferably wherein the bypass element is designed as a semiconductor component, in particular as a diode. Accordingly, it can be easily ensured that the last safety element triggers reliably.

[0056] An advantageous aspect of the device provides that at least one fuse element, in particular the last fuse element, and preferably all fuse elements, is / are designed as a melting fuse(s). Thus, simple and cost-effective fuse elements are provided.

[0057] An advantageous aspect of the device provides that at least one of the transversal elements, in particular at least the last transversal element, preferably all of the transversal elements is designed as an electrical resistor or as a varistor or as a thermistor. The thermistor can be designed as an NTC thermistor. In this way, an element with a changing resistance is provided in a simple manner, so that an operating current which is above the threshold current of the respective fuse element is specifically conducted to a fuse element. An advantageous aspect of the device provides that at least one transversal element and the bypass element are arranged such that a heat exchange can take place between the transversal element and the bypass element in order to reduce a trigger voltage of the bypass element.The waste heat generated in the transverse elements can therefore be used to heat the bypass element and modify its current-voltage characteristic, in particular, to change it so that the bypass element switches from the off-state to the conducting state at a lower voltage. This can further accelerate the tripping characteristic.

[0058] An advantageous aspect of the device provides that a relationship between an electrical resistance of the fuse element and an electrical resistance of the transverse element is configured such that, when the last fuse element is in the interrupted state, the fuse elements switch to the interrupted state through a chain reaction, counter to the chain of fuse paths from the last fuse element to the first fuse element. This further improves the triggering characteristics.

[0059] An advantageous aspect of the device provides that a ratio between an electrical resistance of the last fuse element and an electrical resistance of the last transverse element is in a range between 0.4:1 and 0.8:1, in particular between 0.5:1 and 0.7:1, preferably 0.618:1. This further promotes the triggering or progression of a chain reaction from the transition state to the trigger state.

[0060] Also disclosed is a power supply for a load and / or source, wherein the power supply has a safety device as described above and below at its connection to the load and / or source. The load and / or source has, in particular, an internal resistance of > 0.05 Q, preferably > 0.5 Q. A safety device as described above and below can then be used particularly advantageously.

[0061] Also disclosed is an electrical arrangement comprising a power supply as described above and below and a load, in particular having an internal resistance in the event of a short circuit of > 0.05 Q, preferably > 0.5 Q. In such an arrangement, a safety device, as described above and below, can be used particularly advantageously.

[0062] Also disclosed is an electrical arrangement comprising a power supply as described above and below and a voltage source, in particular a battery, particularly preferably a flow battery, having an internal resistance of > 0.05 Q, preferably > 0.5 Q. In such an arrangement, a safety device, as described above and below, can be used particularly advantageously.

[0063] Further advantages, features, and details will become apparent from the following description, which illustrates various embodiments of the invention with reference to the drawings. The features mentioned in the claims and the description may be essential to the invention individually or in any combination.

[0064] It shows :

[0065] Fig. 1-4 each show an electrical circuit diagram of a safety device in different states and with different levels of detail;

[0066] Fig. 5A is a schematic view of a safety device from the direction of the input contact;

[0067] Fig. 5B is a schematic side view of a fuse device Fig. 5C is a schematic view of a fuse device from the direction of the output contact

[0068] Fig. 6 shows a current curve over time of a safety device and the last safety element;

[0069] Fig. 7 shows the tripping characteristics of a safety device compared to a conventional fuse;

[0070] Fig. 8 shows an electrical arrangement with a power supply, a load and a safety device;

[0071] Fig. 9 shows an electrical arrangement with a power supply, a source and a safety device;

[0072] The fuse device 10 is used according to Fig. 1 to 5C to protect electronic components against overcurrent. The fuse device 10 has an input contact 12 and an output contact 14. A current path 16 extends between the input contact 12 and the output contact 14 and, in an operating state of the fuse device 10, electrically connects the input contact 12 and the output contact 14 with low resistance. Low resistance means resistance values ​​that are < 0.1 Ω, preferably < 0.01 Ω. The components to be protected by the fuse device 10 are designed for the electrical parameters that exist at the fuse device 10 in the operating state.

[0073] 2 and 4, the current path 16 has a chain of fuse paths 18. The chain of fuse paths 18 comprises a plurality of fuse paths, in particular a first fuse path 20 with a first fuse element 22 and a last fuse path 24 with a last fuse element 26. The fuse elements are each designed to change from a through state to an open state when a threshold current of the respective fuse element is exceeded. The fuse elements can be designed as melting fuses and melt when the threshold current is exceeded, so that the melted fuse element is opened. The last fuse path 24 has a last transversal element 28 which is electrically connected in series upstream of the last fuse element 26. Between the first backup path 20 and the last backup path 24, three further backup paths 34A-C are provided.

[0074] The first further securing path 34A has a first further securing element 36A and a first further transverse element 38A.

[0075] The second further securing path 34B has a second further securing element 36B and a second further transverse element 38B.

[0076] The third further securing path 34C has a third further securing element 36C and a third further transverse element 38B.

[0077] In Fig . 5A to C two further backup paths 34D and 34E are shown .

[0078] The fourth further securing path 34D has a fourth further securing element 36D and a fourth further transverse element 38D.

[0079] The fifth further securing path 34E has a fifth further securing element 36E and a fifth further transverse element 38E.

[0080] The further fuse paths 34A-C each have a further fuse element 36A-C and a further transversal element 38A-C connected upstream of the further fuse element 36A-C. The transversal elements are designed as electrical resistors. All fuse paths 34A-34C, 24 following the first fuse path 20 have a series circuit each comprising a transversal element 38A-38C, 28 with a respective fuse element 36A-36C, 26.

[0081] The first securing path 20 does not have a transverse element, but preferably only a securing element 22.

[0082] All fuse paths 34A-34C, 24 following the first fuse path 20 are each connected in parallel with the fuse element 22, 36A-36C of the previous fuse path 20, 34A-34C.

[0083] The resistance values ​​of the fuse elements 22, 36A-36C, of ​​the fuse paths 20, 34A-34C, which are upstream of the last fuse path 24, are all the same.

[0084] The resistance value of the last fuse element 26 is smaller than the resistance value of an upstream fuse element 22, 36A-36C and / or smaller than the resistance value of one of the transverse elements 38A-38C, 28, in particular in the range of 0.5 to 0.7 times, preferably in the range of 0.6 to 0.64, particularly preferably in the range of 0.61 to 0.625 of the resistance value of the other fuse elements 22, 36A-36C and / or transverse elements 38A-38C, 28.

[0085] The resistance values ​​of the transverse elements 38A - 38C of the fuse paths 34A - 34C following the first fuse path 20 and upstream of the last fuse path are all of the same size and, in particular, also of the same size as the resistance values ​​of the respective fuse elements 36A - 36C within a fuse path 34A - 34C.

[0086] In the operating state, as shown in Figs. 1 and 2, an operating current below the threshold current flows through the fuse elements, in particular the last fuse element 26. Accordingly, the fuse elements, in particular the last fuse element 26, remain in the conduction state.

[0087] According to Fig. 4, a bypass path 30 with at least one bypass element 32 is arranged parallel to the last transversal element 28 and the further transversal elements 38A-C, the bypass path 30 being connected at its first end to the input contact 12 and at its second end to the last fuse path 24, in particular between the last fuse element 26 and the last transversal element 28. The bypass element 32 has a voltage-dependent conductivity, in particular a non-linear current-voltage characteristic. The bypass element 32 is further preferably designed to change from a blocking state to a conducting state depending on the voltage drop across the transversal elements. For this purpose, the bypass element 32 has a non-linearity of the current-voltage characteristic in a voltage range in which the fuse device 10 reaches a tripping current.The tripping current serves as a threshold at which subsequent components to be protected could be damaged if no safety device 10 is present.

[0088] When the tripping current of the safety device 10 is reached or exceeded, a voltage drop across the transverse elements is so high that the bypass element 32 switches from the blocking state to the conducting state. For this purpose, the bypass element 32 preferably has a non-linear, voltage-dependent conductivity and is further preferably designed as a passive component, such as a semiconductor component, in particular a diode.

[0089] When the bypass element 32 changes to the conducting state, the entire fuse device 10 also changes to a transition state. The bypass element 32 is preferably designed such that, in the transition state, an additional current is conducted to the last fuse element 26 via the bypass path 30. The operating current thus flowing on the last fuse path 24 exceeds the threshold current of the last fuse element 26, so that the last fuse element 26 changes from the conducting state to the interrupting state, in particular melts, as shown in Fig. 3. Due to the targeted additional supply of current via the bypass path 30, a significantly faster tripping characteristic is achieved after the tripping current is reached.After the last fuse element 26 switches to the interrupted state, the tripping current of the fuse device 10 is distributed among the remaining fuse elements, in particular the first fuse element 22 and the further fuse elements 36A-C. The remaining fuse elements are designed such that they switch to the interrupted state one after the other, preferably in a chain reaction. The chain reaction preferably runs from back to front, i.e., from the third further fuse element 36C, via the second further fuse element 36B, via the first further fuse element 36 to the first fuse element 22.It should be noted that a current continues to flow via the bypass path 30 and after the last fuse element 26 has changed into the interrupted state, the current flowing via the bypass path 30 is now conducted to the third further fuse element 36C, which further accelerates its change into the interrupted state.

[0090] To further improve the triggering characteristics, the fuse elements, in particular the last fuse element 26, can be designed such that the threshold current of a fuse element, in particular of the last fuse element 26, is smaller than the threshold current of the previous fuse element in the chain of fuse paths 18. For example, the threshold current of the last fuse element 26 is smaller than the threshold current of the third additional fuse element 36C. Furthermore, it is conceivable that the threshold current of the fuse elements decreases with each fuse element in the chain of fuse paths 18.For example, the threshold current of the last fuse element 26 is smaller than the threshold current of the third further fuse element 36C and the threshold current of the third further fuse element 36C is smaller than the threshold current of the second further fuse element 36B and the threshold current of the second further fuse element 36B is smaller than the threshold current of the first further fuse element 36A and the threshold current of the first further fuse element 36A is smaller than the threshold current of the first fuse element 22.

[0091] It is further advantageous if a ratio between the electrical resistance of a fuse element and the electrical resistance of the immediately upstream transversal element is designed such that, after the last fuse element 26 changes to the interrupted state, a chain reaction of all fuse elements is ensured. For this purpose, the ratio between the fuse element and the transversal element, in particular between the last fuse element 26 and the last transversal element 28, is preferably in a range between 0.4:1 and 0.8:1, in particular between 0.5:1 and 0.7:1, preferably 0.618:1 or the golden ratio. It is conceivable that the ratio extends over the entire chain of fuse paths 18.

[0092] In Fig. 1 and 2, all fuse elements 22, 36A-C, 26 are in the conduction state. The current through the fuse elements is distributed among the individual fuse elements 22, 36A-C, 26 and the transverse elements 28, 38A - 38C according to the node, current, and voltage rules of electrical circuit technology. If the current flowing from input contact 12 to output contact 14 increases, the voltage drop across the transverse element(s) 28, 38A - 38C also increases. This voltage drop is then also present at the bypass element 32. If the bypass element 32 is designed to suddenly and greatly increase its current flow at a certain voltage, e.g., 0.1 V or 0.15 V, or 0.2 V, as is the case, for example, with a Schottky diode, this increased current flow will also flow through the last fuse element 26. This can lead to the triggering of the last safety element 26. This condition is shown, for example, in Fig. 3.This can now be done very quickly, as the current can increase very quickly here.

[0093] In addition, the overcurrent required to quickly trip the last fuse element 26, e.g., in less than 1 s, even if this last fuse element 26 has a slow tripping characteristic according to Fig. 7, is a fraction of the overcurrent that would be necessary for a quick tripping of all fuse elements.

[0094] The fuse device 10 can advantageously be designed so that now, with undiminished current between input contact 12 and output contact 14, a chain reaction occurs, so that the fuse element 36C connected in parallel with the last fuse path 24 is triggered next, then the fuse element 36B, then the fuse element 36A, and finally the first fuse element 22. This state is shown, for example, in Fig. 4. Since the overcurrent flowing in the fuse elements is then always very high, rapid triggering is ensured, even if all fuse elements have a slow triggering characteristic according to Fig. 7.

[0095] As soon as all fuse elements have switched to the open state according to Fig. 4, the input contact 12 and the output contact 14 are no longer electrically connected. Accordingly, the fuse device 10 is in a tripping state. Consequently, no current can be conducted through the fuse device 10 to the downstream components to be protected.

[0096] 1 to 4, nodes are shown for illustrative purposes which are intended to further clarify the electrical wiring of the safety device 10. The input contact 12 is connected to a first node K1, which is divided into the current path 16 and the bypass path 30. The current path 16 has a second node K2, to which the chain of safety paths 18 is connected. The second node K2 is divided into the first safety path 20 and the first further safety path 34A. After the first further transversal element 38A, a third node K3 is provided which leads on the one hand to the first further safety element 36 and to the second further safety path 34B. After the second further transversal element 38B, a fourth node K4 is provided which leads on the one hand to the second further safety element 36B and to the second further safety path 34B.After the third additional transversal element 38C, a fifth node K5 is provided, which leads, on the one hand, to the third additional safety element 36C and to the third additional safety path 34A-C. After the last transversal element 28, a sixth node K6 is provided, which connects the bypass path 30 to the last safety path 24. Furthermore, a seventh node K7 is provided, which connects the first safety path 20 to the first additional safety path 34A following the first safety element 22 and the first additional safety element 36. The nodes K8 to K10 are also provided accordingly.

[0097] 5A-C show a fuse device 10, wherein the input contact 12 is connected to a first carrier element 40 and the output contact 14 is connected to a second carrier element 42. The first carrier element 40 has a first upper side 40a, a first end point 40b and a second end point 40c. The second carrier element 42 has a second upper side 42a and a third end point 42b and a fourth end point 42c. The first end point 40b corresponds to the sixth node K6 in Figs. 1 to 4. The second end point 40c corresponds to the first node K1 in Figs. 1 to 4. The third end point 42b corresponds to the seventh node K7 in Figs. 1 to 4. The fourth end point 42c corresponds to the tenth node K10 in Figs. 1 to 4.

[0098] The input contact 12 and the output contact 14 are each designed as a flat, particularly cuboid-shaped body. This allows for electrical connections to be made with particularly low losses. Furthermore, space can be saved.

[0099] The input contact 12 is connected to the first support element 40 at the first end point 40c, and in particular, is also secured. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. Furthermore, space can be saved.

[0100] The output contact 14 is connected to the second support element 42 at the fourth end point 42c, and in particular, is also secured. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. Furthermore, space can be saved.

[0101] The bypass element 32 and / or the bypass path 30 is connected, and in particular also secured, at both ends to the first and second end points 40b, 40c of the first support element 40. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. Furthermore, space can be saved.

[0102] The fuse elements 22, 26, 36A-36E are preferably designed in strip form. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. It also saves space.

[0103] The two support elements 40, 42 have the same geometric shape. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. It also saves space.

[0104] The two support elements 40, 42 each have a cylindrical shape, separated at their two end points 40b, 40c, 42b, and 42c, respectively. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. It also saves space.

[0105] The two support elements 40, 42, together with the fuse elements 22, 26, 36A-36E, have a cylindrical shape. This can further improve the electrical properties and further reduce the influence of ambient conditions, such as temperature. It also saves space.

[0106] The two support elements 40, 42 preferably carry the fuse elements 22, 26, 36A-C, particularly preferably on their upper side 40a, 42a, and / or the transverse elements 28, 38A-C and the bypass element 32. The fuse elements are preferably strip-shaped. The first support element 40 connects the first ends of the fuse elements and the second support element 42 connects the second ends of the fuse elements. Furthermore, the transverse elements are arranged in or on the first support element 40. This can be, for example, in the region of the arrows. The arrows are intended to represent the current flow. In addition, the bypass path 30 and the bypass element 32 are indicated.

[0107] In Fig. 6, the individual states of the fuse device 10 (top) and the last fuse element 26 (bottom) are visible. In the operating state of the fuse device 10 between t0 and t1, the input contact 12 and the output contact 14 are connected by means of the current path 16, the fuse elements are in the conducting state, and the bypass element 32 is in the blocking state. As soon as the current itotai at the fuse device 10 rises above the tripping current itotai, G as a threshold according to time t1, the bypass element 32 changes to the conducting state and conducts an additional current to the last fuse element 26, which leads to a sudden increase in the operating current i n at the last fuse element 26 at time ti . Accordingly, the fuse device 10 is in the transition state between times ti and ta . As soon as the operating current i n at the last fuse element 26 the threshold current i n,G, the last fuse element 26 changes to the interrupted state at time ta. Accordingly, no more current flows through the last fuse element 26. The previously described chain reaction occurs, so that the fuse elements gradually change to the interrupted state, with all fuse elements being in the interrupted state at time ta. From time ta, the fuse device 10 is in the tripped state and no more current is conducted between the input contact 12 and the output contact 14.

[0108] Fig. 7 shows the tripping characteristics of conventional fuses compared to a fuse device 10 according to the disclosed development. The diagram shows logarithmically:

[0109] The constant current through the fuses or the

[0110] Fuse device measured in amperes (A) on axis 72 .

[0111] The trigger time in seconds ( s ) on axis 71 .

[0112] The solid lines in the diagram describe the tripping characteristics of various conventional fuses with their respective nominal tripping current in field 72, e.g. for fuses with nominal tripping currents of 2 A, 4 A, 6 A, 10 A, ... 63 A.

[0113] The dashed lines in the diagram describe the tripping characteristics of various fuse devices 10 according to the disclosed development with their respective rated tripping current in field 74, e.g. for fuse devices 10 with rated tripping currents of 2 A, 4 A, 10 A, ... 63 A.

[0114] It can be clearly seen that the safety devices 10 according to the disclosed development have a significantly more current-independent and significantly faster tripping characteristic and can therefore also be adjusted much more precisely to the nominal tripping current.

[0115] Fig. 8 shows an electrical arrangement 100 with a power supply 101 and a load 102. The power supply 101 has a current / voltage converter 104 and a fuse device 10 connected thereto, as described above and below.

[0116] The load 102 can have an internal resistance in the event of a short circuit of > 0.05 Q, preferably > 0.5 Q. In such an arrangement, a safety device, as described above and below, can be used particularly advantageously.

[0117] Fig. 9 shows an electrical arrangement 100 with a power supply 101 and a source 103. The power supply 101 has a current / voltage converter 104 and a fuse device 10 connected thereto, as described above and below.

[0118] Source 103 can be a voltage source. The voltage source is preferably a battery, particularly preferably a flow battery. Such a flow battery arrangement is described, for example, in DE 10 2016 112 004 A1.

[0119] Such a voltage source, especially if it is a battery and particularly preferably if it is a flow battery, often has an internal resistance in the range of > 0.05 Q, preferably > 0.5 Q. If a short circuit develops in the source 103 on the side of the connection to the source 103, a safety device 10, as described above and below, is particularly advantageous. In both figures, the power supply 101 has a safety device 10, as disclosed in this document. This safety device 10 does not necessarily have to be provided in the housing of the power supply 101.

Claims

Patent claims 1. Safety device (10) comprising: - an input contact (12) and an output contact (14), - a current path (16) extending between the input contact (12) and the output contact (14) with a chain of fuse paths (18), the chain of fuse paths (18) having a plurality of fuse elements (22, 26, 36A-E), wherein the chain of fuse paths has a first fuse path (20) with a first fuse element (22) and a last fuse path (24) with a last fuse element (26), wherein the fuse elements (22, 26, 36A-E) are each designed to change from a through state to an open state when a respective threshold current is exceeded, wherein the last fuse path (24) has a last transversal element (28) electrically connected in series upstream of the last fuse element (26), wherein the last fuse path (24) is electrically connected to a previous fuse element (22, 36A-E) in the chain of fuse paths is connected in parallel.

2. Safety device (10) according to claim 1, wherein the safety device (10) is designed such that - that in an operating state of the safety device (10), the input contact (12) and the output contact (14) are electrically connected to one another with low resistance by means of the current path (16), wherein in the operating state an operating current which is smaller than the threshold current of the last fuse element (26) flows over the last fuse element (26) so that the last fuse element (26) remains in the through state, - that in a transition state of the safety device (10), an operating current which is greater than the threshold current of the last safety element (26) flows through the last safety element (26), so that the last safety element (26) changes to the interruption state, and - that the safety device (10) changes from the operating state to the transition state as a function of a voltage drop across the last transversal element (28) and / or a current flowing across the last transversal element (28).

3. Safety device (10) according to one of the preceding claims, wherein several, in particular all, safety elements (22, 36A-36C) of the safety paths (20, 34A-34C) which are arranged upstream of the last safety path (24) have one or more of the following properties: - the same design, - the same resistance in the conducting state, - the same triggering characteristics.

4. Safety device (10) according to one of the preceding claims, wherein several, in particular all, safety paths (34A-34C, 24) following the first safety path 20 have a series circuit each comprising a transversal element (38A-38C, 28) with a safety element (36A-36C, 26) each.

5. Safety device (10) according to one of the preceding claims, wherein the first safety path (20) does not have a transverse element, but preferably only one safety element (22).

6. Safety device (10) according to one of the preceding claims, wherein several, in particular all, safety paths (34A-34C, 24) following the first safety path (20) are each electrically connected in parallel with the safety element (22, 36A-36C) of the preceding safety path (20, 34A-34C).

7. Safety device (10) according to one of the preceding claims, wherein the resistance value of the last safety element (26) is smaller than the resistance value of one, or preferably of all, upstream safety elements (22, 36A-36C) and / or smaller than the resistance value of one, or preferably of all, transverse elements (38A-38C, 28), and the resistance value of the last safety element (26) in particular in the range of 0.5 to 0.7 times, preferably in the range of 0.6 to 0.64, particularly preferably in the range of 0.61 to 0.625 of the resistance value of the other fuse elements (22, 36A-36C) and / or transverse elements (38A - 38C, 28).

8. Safety device (10) according to one of the preceding claims, wherein the resistance values ​​of the transverse elements (38A - 38C) of the safety paths (34A-34C) following the first safety path (20) and preceding the last safety path are all of the same size and, in particular, are also of the same size as the Resistance values ​​of the respective fuse elements (36A - 36C) within their fuse path (34A-34C).

9. Safety device (10) according to one of the preceding claims, wherein the safety device (10) has a bypass path (30).

10. The safety device (10) according to claim 9, wherein the bypass path (30) comprises a bypass element (32), wherein the bypass element (32) in particular has a non-linearity with respect to one or more of the following relationships: a. current to voltage, b. resistance to voltage, c. resistance to current, d. resistance to temperature.

11. Safety device (10) according to one of claims 9 or 10, wherein the bypass element (32) has a semiconductor structure, wherein the semiconductor structure in particular has a pn junction.

12. Safety device (10) according to one of claims 9 to 11, wherein the bypass element (32) has a non-linear current-voltage characteristic and is preferably designed to change from a blocking state to a conducting state.

13. Safety device (10) according to one of claims 9 to 12, wherein the bypass element (32) is designed to generate a non-linear current increase depending on a voltage drop across the last transverse element (28), in particular to have a non-linear accelerated current rise, preferably to change from the blocking state to the conducting state.

14. Safety device (10) according to one of the preceding claims 9 to 13, wherein the bypass element (32) has its non-linearity of the current-voltage characteristic in a voltage range in which the safety device (10) reaches a tripping current at which the safety device (10) changes from the operating state to the transition state and the bypass element (32) is preferably designed to change from the blocking state to the conducting state in the voltage range.

15. A safety device (10) according to any one of the preceding claims 9 to 14, wherein the bypass path (30) is connected at one end to the input contact (12) and the bypass path (30) is connected at its other end to the last safety path (24) between the last transverse element (28) and the last safety element (26).

16. Fuse device (10) according to one of claims 9 - 15, wherein the bypass element (32) is designed to conduct a current by means of the bypass path (30) to the last fuse element (26) in the transition state, so that the operating current at the last fuse element (26) exceeds the threshold current of the last fuse element (26) and the last fuse element (26) changes from the through state to the open state.

17. Safety device (10) according to one of the preceding claims, wherein the last transverse element (28) -32- is designed to reduce its resistance when the voltage drop across the last transversal element (28) rises above a threshold value and / or the current flowing across the last transversal element (28) rises above a threshold value.

18. Safety device (10) according to one of the preceding claims, wherein the safety device (10) is designed such that in a tripping state of the safety device (10) all the safety elements (22, 26, 36A-E) are in the interrupted state and the input contact (12) and the output contact (14) are not electrically connected by means of the current path (16).

19. Safety device (10) according to one of the preceding claims, wherein in the chain of safety paths (18) between the first safety path (20) and the last safety path (24) a further safety path (34A-E) is provided with a further safety element (36A-E) and a further transversal element (38A-E) electrically connected in series upstream of the further safety element (36A-E), - wherein the further fuse path (34A-E) is electrically connected in parallel to a previous fuse element (22, 36A-E) in the chain of fuse paths (18), and / or - wherein the transverse elements (28,38A-E) are electrically connected in series.

20. Safety device (10) according to one of the preceding claims, wherein the threshold current of the last fuse element (26) is smaller than the threshold current of the previous fuse element (22,36A-E) in the chain of fuse paths (18). -33- 21. A safety device (10) according to any one of the preceding claims, wherein the respective threshold current of the safety elements (22, 26, 36A-E) decreases with each additional safety element (22, 26, 36A-E) in the chain of safety paths (18).

22. Safety device (10) according to one of the preceding claims, wherein the bypass element (32) has a non-linear voltage-dependent conductivity and / or is designed as a passive component, preferably wherein the bypass element (32) is designed as a semiconductor component, in particular as a diode.

23. Safety device (10) according to one of the preceding claims, wherein the safety elements (22, 26, 36A-E) are designed as fuses.

24. Safety device (10) according to one of the preceding claims, wherein at least one of the transverse elements (28,38A-E), in particular at least the last transversal element (28), preferably all transversal elements (28,38A-E) are designed as electrical resistors or as varistors or as thermistors.

25. Safety device (10) according to one of the preceding claims, wherein the safety device (10) has a first carrier element (40) which is electrically, and in particular also mechanically, connected to the input contact (12).

26. Safety device (10) according to one of the preceding Claims, wherein the transverse elements (38A-E, 28) are arranged on or in the first support element (40). -34- 27. Safety device (10) according to one of the preceding Claims, wherein the safety device (10) has a second carrier element (42) which is electrically, and in particular also mechanically, connected to the output contact (14).

28. A safety device (10) according to claim 26, wherein the safety elements (22, 26, 36A-36E) are each electrically connected between the two carrier elements (40, 42).

29. Safety device (10) according to one of the preceding Claims 26 to 27, wherein the two support elements (40, 42) each have an upper side (40a, 42a) and the securing elements (22, 26, 36A-36E) are each attached to the upper side of the support elements (40, 42) 30. A securing device (10) according to any one of the preceding claims, wherein the securing elements (22, 26, 36A-36E) are strip-shaped.

31. Safety device (10) according to one of the preceding claims, wherein the bypass path (30) and / or the bypass element (32) is / are each connected to the two end points of the first carrier element (40).

32. Safety device (10) according to one of the preceding claims, wherein the two support elements (40, 42) have the same geometric shape.

33. A securing device (10) according to any one of the preceding claims, wherein the two support elements (40, 42) each have a cylindrical shape which is separated at each of their two end points (40b, 40c, 42b, 42c). -35- 34. A securing device (10) according to any one of the preceding claims, wherein the two support elements (40, 42) together with the securing elements (22, 26, 36A-36E) have a cylindrical shape.

35. Safety device (10) according to one of the preceding claims, wherein the input contact (12) and the output contact (14) are each designed as a flat, in particular cuboid-shaped body.

36. Power supply (101) for a load (102) and / or source (103), in particular having an internal resistance > 0.05 Q, preferably > 0.5 Q, wherein the power supply (101) has a safety device (10) according to one of the preceding claims at its connection to the load (102) and / or source (103).

37. Electrical arrangement (100) comprising a power supply (101) according to the preceding claim 36 and a load (102), in particular having an internal resistance in the event of a short circuit of > 0.05 Q, preferably h 0.5 Q .

38. Electrical arrangement (100) according to the preceding claim 37, comprising a source (103), in particular a voltage source, e.g. a battery, particularly preferably a flow battery, having an internal resistance > 0.05 Q, preferably > 0.5 Q. -36-

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