SI24524A

SI24524A - Fuse with at least one melting element and ability of involuntary termination with electric circuit running trough it and with such fuse equipped electric circuit

Info

Publication number: SI24524A
Application number: SI201300339A
Authority: SI
Inventors: Mitja KoprivĹˇek
Original assignee: Razvojni Center Enem Novi Materiali D.O.O.
Priority date: 2013-10-15
Filing date: 2013-10-15
Publication date: 2015-04-30
Also published as: SI24524B

Abstract

Z namenom, da bi bilo možno električni tokokrog (C') iz različnih razlogov prisilno prekiniti tudi kadarkoli pred pojavom nadtoka, predlagana varovalka (1) z vsaj enim talilnim elementom (2), obsegajoča telo (10) iz električno izolacijskega materiala, s katerim je obdan vsakokrat razpoložljiv in nazivni vrednosti (I) električnega toka prirejen talilni element (2), ki je električno povezan z vsakokrat razpoložljivima električnima kontaktoma (11, 12), ki sta razporejena na zunanji površini omenjenega telesa(10) varovalke (1) in preko katerih je varovalka (1) električno povezljiva v vsakokrat razpoložljiv primarni električni tokokrog (C'), ki je s pomočjo varovalke (1) zaščiten proti nadtoku, po izumu pa tovrstna varovalka (1) obsega upor (3), še zlasti od električne napetosti odvisen upor (3), namreč varistor, katerega upornost je obratno sorazmerna z napetostjo, kateri je izpostavljen, pri čemer je omenjen upor (3) razporejen neposredno ob vsakokratnem talilnem elementu (2) in torej v toplotno-prevodnemstiku z omenjenim talilnim elementom (2), in pri čemer je omenjeni upor (3) električno povezan v sekundarni električni tokokrog (C") z vsaj enim stikalom (4), ki ga je možno po potrebi aktivirati neodvisno od razmer v primarnem tokokrogu (C').In order to allow the electrical circuit (C ') for various reasons to be interrupted even before the occurrence of the overflow, a fuse (1) with at least one melting element (2), comprising a body (10) of an electrically insulating material, with which is an enclosed melting element (2), which is electrically connected to the respective electrical contacts (11, 12) available each time on the external surface of said body (10) of the fuse (1) and through which the fuse (1) is electrically connected to the available primary electric circuit (C '), which is protected against overcurrent by means of a fuse (1) and, according to the invention, this fuse (1) comprises a resistor (3), in particular of electric (3), namely, a varistor whose resistance is inversely proportional to the voltage to which it is exposed, said resistor (3) being arranged directly at the respective melting element entu (2), and therefore in thermal conductivity with said melting element (2), and wherein said resistor (3) is electrically connected to the secondary electrical circuit (C ") with at least one switch (4), which is possible after needs to be activated independently of the conditions in the primary circuit (C ').

Description

Varovalka z vsaj enim talilnim elementom in zmožnostjo prisilne prekinitve skoznjo potekajočega električnega tokokroga ter s tovrstno varovalko opremljen električni tokokrogA fuse with at least one melting element and the ability to force interruptions through an electrical circuit in progress and an electrical circuit equipped with such fuse

Izum se nanaša na varovalko z vsaj enim talilnim elementom, ki jo je možno tudi v primeru, kadar električni tok skoznjo še ne preseže vnaprej določene nazivne vrednosti, po potrebi deaktivirati in s tem prisilno prekiniti električni tokokrog.The invention relates to a fuse with at least one melting element which, even if the electric current does not exceed a predetermined nominal value, is deactivated if necessary, thereby forcing the electrical circuit to be interrupted.

Po mednarodni razvrstitvi patentov izum te vrste spada na področje varovalk s talilnim elementom, ki so namenjene za zaščito električnega tokokroga proti preobremenitvam. Nadalje je tak izum lahko razvrščen tudi na področje elektrotehnike in v okviru slednje k osnovnim električnim komponentam, namreč k prenapetostnim zaščitnim komponentam na osnovi varistorjev s pozitivno temperaturno karakteristiko.According to the international classification of patents, the invention of this type falls within the scope of fuses with a melting element designed to protect the electrical circuit against overloads. Further, such an invention can also be classified in the field of electrical engineering and, within the latter, to basic electrical components, namely, surge protection components based on varistors with a positive temperature characteristic.

Pri tem je izum osnovan na problemu, kako zasnovati varovalko z vsaj enim talilnim elementom, pri kateri bo brez znatnega povečanja števila sestavnih delov in zahtevnosti njene izdelave in torej nas ekonomičen način zagotovljena možnost prisilne prekinitve skoznjo potekajočega električnega tokokroga tudi v primeru, kadar električni tok v omenjenem tokokrogu še ne preseže vnaprej določene nazivne vrednosti, pri kateri pride do prekinitve vsakokratnega talilnega elementa.The invention is based on the problem of how to design a fuse with at least one melting element, in which without a significant increase in the number of components and the complexity of its manufacture, and thus in a cost-effective way, we are guaranteed the possibility of forced interruption through an ongoing electrical circuit, even when the electric current does not, in the said circuit, exceed the predetermined nominal value at which the melt element is interrupted.

Strokovnjakom so znane varovalke s talilnim elementom, ki sestojijo iz telesa iz električno neprevodnega materiala, npr. iz keramike, v katerem je na voljo skoznji prehod, v katerem je vstavljen talilni element iz električno prevodnega materiala, ki je električno povezan s kontaktoma, ki sta nameščena na zunanji površini omenjenega telesa. Talilni element je običajno obdan s sredstvom za gašenje obloka, prednostno s kremenčevim peskom ali podobnim. Omenjen talilni element je tako dimenzioniran, da skozenj lahko teče električni tok določene jakosti, ob pojavu nadtoka pa se talilni element stali, zaradi česar se tokokrog skozi varovalko prekine.Experts are aware of fuses with a melting element consisting of a body of electrically non-conductive material, e.g. of ceramics, in which a through passage is provided, in which a melting element of electrically conductive material is inserted, which is electrically connected to the contacts placed on the outer surface of said body. The melting element is typically surrounded by an arc extinguishing agent, preferably silica sand or the like. The said melting element is so dimensioned that an electric current of a certain strength can flow through it, and upon the occurrence of an overcurrent, the melting element melts, causing the circuit to break through the fuse.

Po drugi strani je strokovnjakom znano, da v določenih primerih uporaba tovrstne varovalke ne zagotavlja povsem zanesljive zaščite električnega tokokroga. Še zlasti v primeru visokonapetostnih enosmernih tokokrogov z enosmerno napetostjo npr. 1.500 V (DC) in tokom približno 100 A (DC), obstoji možnost pojavljanja okvar, ki so npr. lahko povezane s pojavom obloka v stikalih in posledično sprijemanja kontaktnih elementov, ali podobnih, do česar pa lahko prihaja tudi v primerih, kadar tok skozi varovalko ne preseže nazivne vrednosti in torej varovalka tokokroga ne prekine. Taki primeri nastopijo npr. v večjih sklopih za akumuliranje električne energije, v fotovoltaičnih napravah in podobnih. Tačas precej aktualno področje predstavljajo tudi električno gnana vozila, pri katerih je v primeru trkov ali drugih nezgod ali tudi okvar potrebno iz preventivnih razlogov v trenutku prekiniti električni tokokrog. V tem kontekstu je tudi znano, da so v vozilih večidel vgrajeni senzorji za zaznavanje določenih fizikalnih veličin, npr. pospeškov, s pomočjo katerih je potem zagotovljeno proženje napihljivih varnostnih blazin ali po izbiri aktiviranje drugih varnostnih naprav. Zahvaljujoč tem spoznanjem je bila v DE 203 15 849 U predlagana varovalka s talilnim elementom, kateri je prigrajen pirotehnični prožilni sklop, ki se ga pod določenimi pogoji aktivira, tako da s pomočjo eksplozije prekine talilni element tudi v primeru, ko električni tok skozi talilni element še ne preseže vnaprej določene nazivne vrednosti. Vgradnja omenjenega pirotehničnega sklopa znatno poveča število sestavnih delov in zapletenost same varovalke, obenem pa narekuje uporabo povsem drugačne tehnologije izdelave in je zato razmeroma neekonomična. Uporaba tovrstne varovalke pri vozilu v primeru trka in ob razlitju hlapljivih tekočin ali v primeru uhajanja plinov lahko ob aktiviranju omenjenega pirotehničnega sklopa izzove popolnoma nepredvidljive učinke.On the other hand, it is known to experts that, in certain cases, the use of this type of fuse does not completely guarantee the protection of the electrical circuit. Especially in the case of high voltage direct current dc circuits e.g. 1,500 V (DC) and current around 100 A (DC), there is a possibility of failure, such as may be related to the appearance of an arc in the switches and, consequently, to the clamping of the contact elements, or the like, which may also occur in cases where the current through the fuse does not exceed the rated value and therefore does not break the circuit. Such examples occur, for example. in larger power accumulation assemblies, in photovoltaic devices and the like. Electrically driven vehicles, which in the event of collisions or other accidents or breakdowns, need to interrupt the electrical circuit immediately for preventative reasons, are also a very topical area. In this context, it is also known that sensors for detecting specific physical quantities, e.g. accelerations, which then provide for the triggering of inflatable airbags or optionally the activation of other safety devices. Thanks to these findings, a fuse with a melter element was proposed in DE 203 15 849 U, to which a pyrotechnic actuator is mounted, which, under certain conditions, is activated by interrupting the melting element by means of an explosion, even if the electrical current through the melter element has not yet exceeded a predefined nominal value. The installation of said pyrotechnic assembly significantly increases the number of components and the complexity of the fuse itself, but at the same time dictates the use of completely different manufacturing technology and is therefore relatively uneconomical. The use of this kind of fuse in a vehicle in the event of a collision and in the event of spillage of volatile liquids or in the event of gas leakage can cause completely unpredictable effects when the pyrotechnic assembly is activated.

Nadalje je iz EP 1 577 906 A2 znana varovalka s talilnim elementom, ki predstavlja del primarnega električnega tokokroga in ki se obenem nahaja v toplotno prevodnem stiku s temperaturno odvisnim uporom, skozi katerega poteka sekundami električni tokokrog, v katerem sta načeloma v območju varovalke predvidena med seboj razmaknjena električno prevodna kontakta, ki sta med seboj električno povezana preko talilnega elementa, kateremu se med naraščanjem temperature povečuje električna upornost. Ko je temperatura dovolj visoka, se upornost poveča do te mere, da element postane praktično neprevoden, kar v običajnih razmerah pomeni njegovo stalitev in s tem prekinitev tokokroga. Varovalka s talilnim elementom predstavlja zaščito primarnega električnega tokokroga proti preobremenitvi. Sekundami tokokrog je predviden zgolj za prisilno prekinitev primarnega tokokroga v primeru, kadar nazivni tok v prvem tokokrogu ne preseže nazivne vrednosti in se talilni element še ne stali zaradi nadtoka. V takem primeru se ob primernem impulzu aktivira omenjen sekundami tokokrog, v katerem tok teče skozi temperaturno spremenljiv upor, v katerem se generira toplota, ki zahvaljujoč omenjenemu toplotno-prevodnemu stiku prehaja na talilni element, ki se potem stali. Tudi v tem primeru je za vzpostavitev funkcije prisilnega odklopa potrebnih več dodatnih sestavnih delov. Ker je omenjen talilni element v toplotno prevodnem stiku z omenjenim dodatnim temperaturno odvisnim uporom, je po prekinitvi primarnega tokokroga zaradi nadtoka načeloma možno, da se preko omenjenega elementa, ki je v stiku s talilnim elementom, vsaj začasno vzpostavi obvodni tokokrog, tako da je električni tokokrog kljub prekinjenemu talilnemu elementu vsaj določen čas lahko še vedno vzpostavljen.Furthermore, EP 1 577 906 A2 discloses a fuse with a melting element which forms part of a primary electrical circuit and which is simultaneously in thermal conductive contact with a temperature-dependent resistance through which an electrical circuit is passed in seconds, in principle in which a fuse is provided between electrically conductive contacts spaced apart, which are electrically connected to one another by means of a melting element, which increases electrical resistance as the temperature increases. When the temperature is high enough, the resistance increases to such an extent that the element becomes virtually non-conductive, which, in normal conditions, means its positioning, thereby breaking the circuit. A fuse with a melter element protects the primary electrical circuit against overload. Seconds of the circuit are intended solely for the forced interruption of the primary circuit in the case where the rated current in the first circuit does not exceed the rated value and the melting element is not still melting due to overcurrent. In such a case, with a suitable impulse, the circuit mentioned in seconds is activated, in which the current flows through a temperature-varying resistor in which heat is generated, which, due to said thermal-conductive contact, passes to the melting element, which is then melted. Even in this case, several additional components are required to set up the forced disconnect function. Since said melting element is in thermal conductive contact with said additional temperature dependent resistor, it is in principle possible, after interruption of the primary circuit due to overcurrent, to at least temporarily establish a bypass circuit through said element in contact with the melting element so that the electrical the circuit may remain in place for at least some time despite the broken melting element.

Izum se nanaša na varovalko z vsaj enim talilnim elementom in z zmožnostjo prekinitve skoznjo potekajočega električnega tokokroga, obsegajoča telo iz električno izolacijskega materiala, s katerim je obdan vsaj en vsakokrat razpoložljiv in nazivni vrednosti električnega toka prirejen talilni element, ki je električno povezan z vsakokrat razpoložljivima električnima kontaktoma, ki sta razporejena na zunanji površini omenjenega telesa varovalke, in preko katerih je varovalka električno povezljiva v vsakokrat razpoložljiv primarni električni tokokrog, kije s pomočjo varovalke zaščiten proti nadtoku.The invention relates to a fuse with at least one melting element and with the ability to break through an electrical circuit, comprising a body of electrically insulating material, which surrounds at least one of the available and rated electric current fused element, which is electrically connected to each available electrical contacts arranged on the outer surface of said fuse body and through which the fuse is electrically connected to the primary primary circuit which is protected against over current by means of a fuse.

Po izumu je predvideno da tovrstna varovalka nadalje obsega upor, še zlasti od električne napetosti odvisen upor, namreč varistor, katerega upornost je obratno sorazmerna z napetostjo, kateri je izpostavljen, pri Čemer je omenjen upor razporejen neposredno ob vsakokratnem talilnem elementu in torej v toplotnoprevodnem stiku z omenjenim talilnim elementom, in pri čemer je omenjeni upor električno povezan v sekundami električni tokokrog z vsaj enim stikalom, ki ga je možno po potrebi aktivirati neodvisno od razmer v primarnem tokokrogu.According to the invention, it is envisaged that such a fuse further comprises a resistor, in particular a voltage dependent resistor, namely a varistor whose resistance is inversely proportional to the voltage to which it is exposed, said resistor being disposed directly next to the respective melting element and thus in thermal conductive contact with said melting element, and wherein said resistor is electrically connected in seconds with an electrical circuit having at least one switch which can be activated independently of the primary circuit conditions if necessary.

Nadalje je po izumu predvideno, da je vsakokraten talilni element skupaj z omenjenim uporom v notranjosti telesa varovalke obdan s polnilom za gašenje električnega obloka, še zlasti s kremenčevim peskom.It is further contemplated according to the invention that each melting element together with said resistance inside the fuse body is surrounded by a filler for extinguishing the electric arc, in particular silica sand.

Še nadalje je po izumu predvideno, da sekundami tokokrog, ki vključuje omenjen upor, vključuje tudi stikalo, kije daljinsko upravljivo stikalo.According to the invention, it is further provided that in seconds the circuit including said resistor also includes a switch which is a remote controlled switch.

Še nadalje je po izumu predvideno, da sta na telesu varovalke, prednostno na zunanji površini le-tega, poleg z vsakokratnim talilnim elementom električno povezanih električnih priključkov za povezavo varovalke v primarni električni tokokrog predvidena še vsaj dva z omenjenim uporom električno povezana električna priključka za povezavo varovalke v sekundami električni tokokrog.According to the invention, it is further provided that at least two electrically connected electrical connections are provided on the fuse body, preferably on the outer surface thereof, in addition to the respective melting element of electrically connected electrical connections for connecting the fuse to the primary electrical circuit. fuses in seconds electrical circuit.

Po izumu je predvidena varovalka, ki obsega več kot en talilni element, še zlasti npr. dva talilna elementa, pri čemer pa je vsak izmed vsakokrat razpoložljivih talilnih elementov razporejen v toplotno-prevodnem stiku z omenjenim uporom.According to the invention, a fuse is provided comprising more than one melting element, in particular e.g. two melting elements, each of which is each of the available melting elements arranged in thermal-conductive contact with said resistor.

Izum se nanaša tudi na električni tokokrog, obsegajoč vir električne napetosti in vsaj en porabnik, pri čemer tovrsten tokokrog vključuje tudi vsaj eno varovalko po kateremkoli od zahtevkov, omenjeni vir električne napetosti pa prednostno predstavlja vir enosmerne električne napetosti.The invention also relates to an electrical circuit comprising a power source and at least one consumer, said circuit also including at least one fuse according to any one of the claims, said electrical source preferably being a direct current source.

Izum bo v nadaljevanju obrazložen s primerom izvedbe, ki je prikazan na priloženi skici, kjer kažeThe invention will hereinafter be explained by the embodiment shown in the accompanying drawing, where it shows

Sl. 1 shematično ponazorjen talilni element varovalke z dodanim varistorjem,FIG. 1 schematically illustrated fuse element with varistor added,

Sl. 2 konkretizirano shemo talilnega elementa po Sl. 1,FIG. 2 is a schematic diagram of a melting element of FIG. 1,

Sl. 3 shematično ponazorjeno izvedbo standardne varovalke tipa CH,FIG. 3 is a schematic illustration of a standard fuse type CH,

Sl. 4 shematično ponazorjeno izvedbo standardne varovalke tipa NV,FIG. 4 is a schematically illustrated embodiment of a standard NV type fuse,

Sl. 5 pa električni tokokrog z vgrajeno varovalko po izumu.FIG. 5 is an electrical circuit with a fuse according to the invention.

Po izumu je predvidena varovalka 1 vsaj enim talilnim elementom 2 (Sl. 1 in 2) in z zmožnostjo prekinitve skoznjo potekajočega električnega tokokroga. Tovrstna varovalka 1 je v standardni izvedbi tipa CH z enim talilnim elementom 2 prikazana na Sl. 3, v prav tako standardni izvedbi tipa NV z enim talilnim elementom 2 pa na Sl. 4.According to the invention, a fuse 1 is provided for at least one of the melting elements 2 (Figs. 1 and 2) and capable of breaking through an electrical circuit. Such a fuse 1 is shown in FIG. 1 with a single melting element 2 in FIG. 3, also in the standard version of the NV type with one melting element 2, in FIG. 4.

Varovalka 1 obsega telo 10 iz električno izolacijskega materiala, s katerim je obdan vsakokrat razpoložljiv in nazivni vrednosti I električnega toka v tokokrogu C' prirejen talilni element 2, ki je električno povezan z vsakokrat razpoložljivima električnima kontaktoma 11, 12, ki sta razporejena na omenjenem telesu 10 varovalke 1, v prikazanih primerih na zunanji površini le-tega, in preko katerih je varovalka 1 električno povezljiva v vsakokrat razpoložljiv primarni električni tokokrog C', ki je na ta način s pomočjo varovalke 1 zaščiten proti nadtoku.The fuse 1 comprises a body 10 of electrically insulating material, by which the melt element 2, electrically connected to the electrical contacts 11, 12 arranged on said body, is surrounded by the available and rated current I current in circuit C '. 10 of the fuse 1, in the shown cases on the outer surface thereof, and through which the fuse 1 is electrically connected to the primary primary circuit C 'available at each time, which is thus protected against over current by means of the fuse 1.

Po izumu je predvideno, da omenjena varovalka 1 nadalje obsega upor 3, še zlasti od električne napetosti odvisen upor 3, namreč varistor, katerega karakteristika je tako izbrana, daje njegova upornost obratno sorazmerna z električno napetostjo in tokom, katerima je izpostavljen. Omenjeni upor 3 je razporejen neposredno ob talilnem elementu 2, ki je v tem primeru en sam, in torej v toplotno-prevodnem stiku z omenjenim talilnim elementom 2. Obenem pa je omenjeni upor 3 električno povezan v sekundami električni tokokrog C, ki je opremljen z vsaj enim stikalom 4, ki je po izbiri daljinsko upravljano in ki ga je možno po potrebi aktivirati popolnoma neodvisno od razmer v primarnem tokokrogu C', tako da skozenj teče tok Γ, ki povzroči segrevanje omenjenega upora 3. Pred aktiviranjem omenjenega stikala 4 je namreč sekundami tokokrog C razklenjen, upornost omenjenega upora 3 pa je zelo visoka, tako da neposredno ob talilnem elementu 2 nameščen upor 3 v takem stanju nima nikakršnega vpliva na dogajanje v primarnem tokokrogu C'. Ob pojavu nadtoka v primarnem tokokrogu C' se torej talilni element 2 vsaj na enem mestu stali in varovalka 1 deluje popolnoma enako kot doslej znane tovrstne varovalke.According to the invention, said fuse 1 further comprises a resistor 3, especially a voltage dependent resistor 3, namely a varistor whose characteristic is so selected that its resistance is inversely proportional to the electrical voltage and current to which it is exposed. Said resistor 3 is arranged directly adjacent to the melting element 2, which is in this case single, and thus in thermal-conductive contact with said melting element 2. At the same time, said resistor 3 is electrically connected in seconds to an electrical circuit C which is equipped with at least one switch 4, which is optionally remotely operated and which can be activated, if necessary, completely independent of the conditions in the primary circuit C ', so that a current Γ is flowing through it, which causes the said resistor to heat up. for seconds the circuit C is unlocked and the resistance of said resistor 3 is very high, so that a resistor 3 in such a state directly adjacent to the melting element 2 has no effect on the event in the primary circuit C '. In the event of an overcurrent in the primary circuit C ', the melting element 2 is then melted at least in one place and the fuse 1 operates exactly the same as the fuses of the kind known hitherto.

Kadar tok I v primarnem tokokrogu C' ne presega nazivne vrednosti, vendar bi kljub temu želeli primarni tokokrog C' iz različnih razlogov nemudoma prekiniti, se z vklopom stikala 4 sklene sekundami tokokrog C in se ga poveže z virom napetosti, nakar skozi upor 3 steče tok Γ, pri čemer se uporu 3 zniža upornost, obenem pa se upor 3 hitro in zelo intenzivno segreje. Generirana toplota se z upora 3 prevede na talilni element 2, ki se zato vsaj na enem mestu stali, s čimer se tudi v odsotnosti nadtoka prisilno prekine primarni tokokrog C'.When the current I in the primary circuit C 'does not exceed the rated value, but still wants to interrupt the primary circuit C' for various reasons immediately, by switching on switch 4, it terminates for seconds with a circuit C and connects it to a voltage source and then flows through the resistor 3. current Γ, in which the resistance 3 decreases the resistance and at the same time the resistance 3 heats up rapidly and very intensively. The generated heat is transferred from the resistor 3 to the melting element 2, which is therefore melted in at least one place, thereby forcing the primary circuit C 'to be forced off even in the absence of overcurrent.

Nadalje je po izumu predvideno, da je talilni element 2 skupaj z omenjenim uporom 3 v notranjosti telesa 10 varovalke 1 obdan s polnilom za obvladovanje učinkov oz. gašenje električnega obloka, še zlasti s kremenčevim peskom.Further, according to the invention, it is envisaged that the melting element 2 together with said resistor 3 is surrounded by a filler in the interior of the body 10 of the fuse 1 for controlling the effects or. quenching the electric arc, especially with silica sand.

V skladu s povedanim sta torej na zunanji površini telesa 10 varovalke 1 (Sl. 3 in 4) poleg s talilnim elementom 2 električno povezanih električnih priključkov 11, 12 za povezavo varovalke 1 v primarni električni tokokrog C' predvidena še vsaj dva z omenjenim uporom 3 električno povezana električna priključka 13', 13 za povezavo varovalke 1 v sekundami električni tokokrog C.Accordingly, at the outer surface of the body 10 of the fuse 1 (Figs. 3 and 4), in addition to the melting element 2 of the electrically connected electrical connections 11, 12, at least two of said resistors 3 are provided for connecting the fuse 1 to the primary electrical circuit electrically connected electrical terminals 13 ', 13 to connect fuse 1 in seconds electrical circuit C.

V primeru zmogljivejše varovalke za zaščito tokokrogov z višjim nazivnim tokom, sta lahko predvidena vsaj dva talilna elementa 2. V takem primeru je vsak od vsakokrat razpoložljivih talilnih elementov 2 razporejen v toplotno-prevodnem stiku z omenjenim uporom 3.In the case of a more powerful fuse for the protection of circuits with a higher rated current, at least two melting elements may be provided 2. In this case, each of the available melting elements 2 is arranged in thermal conductive contact with said resistor 3.

Predmet izuma je tudi električni tokokrog, ki obsega vsaj vir 5 električne napetosti, še zlasti enosmerne napetosti, in vsaj en porabnik 6, obenem pa tudi vsaj eno varovalko 1 s predhodno navedenimi značilnostmi.The subject of the invention is also an electrical circuit comprising at least a source of 5 voltages, in particular direct current, and at least one consumer 6, and at least one fuse 1 with the above characteristics.

Claims

A fuse (1) with a melting element (2) and capable of breaking through an electrical circuit, comprising a body (10) of electrically insulating material, which surrounds the melting element (2) available at each time and the rated value (I) ), which is electrically connected to the available electrical contacts (11, 12) arranged on the outer surface of said fuse body (10) and through which the fuse (1) is electrically connected to the primary electrical circuit (C) available at each time. '), which is protected against overcurrent by means of a fuse (1), characterized in that it further comprises a resistor (3), especially a voltage-dependent resistor (3), namely a varistor whose resistance is inversely proportional to the voltage, which is exposed, said resistor (3) being disposed directly adjacent to the melting element (2) and thus in thermal conductive contact with said melting element (2), and wherein said resistor (3) electrically connected in seconds to an electrical circuit (C) with at least one switch (4) that can be activated independently of the primary circuit conditions (C ') if necessary.

Fuse according to claim 1, characterized in that the melting element (2) together with said resistor (3) is surrounded by a filler for extinguishing the electric arc, in particular silica sand, inside the body (10) of the fuse (1).

Fuse according to claim 1 or 2, characterized in that for seconds the circuit (C) including said resistor (3) includes a switch (4) which is a remote controlled switch.

Fuse according to any one of the preceding claims, characterized in that the body (10), preferably on its outer surface, is adjacent to the melting element (2) of electrically connected electrical connections (11, 12) for connecting the fuse (1) to the primary electrical circuit (C ') is provided with at least two resistors (3) electrically connected electrical terminals (13', 13) for connecting the fuse (1) in seconds to the electrical circuit (C).

Fuse according to any one of the preceding claims, characterized in that it comprises more than one melting element (2), wherein each of the available melting elements (2) is arranged in thermal conductive contact with said resistor (3).

An electrical circuit comprising a voltage source (5) and at least one consumer (6), characterized in that it also includes at least one fuse (1) according to any one of claims 1-4.

Electric circuit according to claim 6, characterized in that the electrical source (5) is a direct current source.