Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
  • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
  • H01C7/12—Overvoltage protection resistors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
  • H01H85/041—Fuses, i.e. expendable parts of the protective device, e.g. cartridges characterised by the type
  • H01H85/048—Fuse resistors
  • H01H2085/0486—Fuse resistors with voltage dependent resistor, e.g. varistor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/46—Circuit arrangements not adapted to a particular application of the protective device
  • H01H2085/466—Circuit arrangements not adapted to a particular application of the protective device with remote controlled forced fusing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
  • H01H85/041—Fuses, i.e. expendable parts of the protective device, e.g. cartridges characterised by the type
  • H01H85/044—General constructions or structure of low voltage fuses, i.e. below 1000 V, or of fuses where the applicable voltage is not specified
  • H01H85/045—General constructions or structure of low voltage fuses, i.e. below 1000 V, or of fuses where the applicable voltage is not specified cartridge type
  • H01H85/0458—General constructions or structure of low voltage fuses, i.e. below 1000 V, or of fuses where the applicable voltage is not specified cartridge type with ferrule type end contacts

Definitions

• the invention refers to a fuse, which comprises at least one melting member and which is allowed to be deactivated when required, although the electric current there-through has not overcome each pre-determined nominal value, by which a forced interruption of each electric circuit is achieved, into which such fuse is integrated.
• such invention belongs to protective elements, which are furnished with a melting member and suitable for protection of electric circuits against overloading. Moreover, such invention can also belong to electricity, namely to basic electric components which are suitable for overvoltage protection and in which a varistor having a positive temperature characteristics is applied.
• the purpose of the invention is to create a fuse with at least one melting member, which could without essentially increasing the number of consisting parts or complexity of manufacturing thereof and therefore in an economical manner enable forced interruption of each electric circuit, into which the fuse is integrated, even in the case, when the electric current in said circuit would not exceed a predetermined nominal value, at which the melting member would normally have to be interrupted.
• Fuses with melting member which are well-known to those skilled in the art, usually comprise a body, which is made of an electric insulating material like e.g. ceramics and is furnished with a passage, through which a melting member is inserted, which consists of an electric conductive material and is electrically connected with contact terminals, which are located on the external surface of said body.
• Said melting member is surrounded with appropriate arc extinguishing material, usually with silica or the like. Dimensions of said melting member are adjusted to conducting electric current below a pre-determine value, and is melted as soon as an excess current occurs, by which the electric circuit throughout said fuse is interrupted.
• a fuse with a melting member which is disclosed in EP 1 577 906 A2, is integrated into a primary electric circuit and is arranged in a heat-conductive relationship with a temperature depending resistor, through which a secondary electric circuit is established, in which two contact terminals are arranged apart from each other in the area of the fuse, which are electrically interconnected via appropriate melting member, the resistance of which is increasing by increasing proportionally with increasing of the temperature. As soon as the temperature is sufficiently high, the resistance is increased practically up to that level, where the resistor is not conductive anymore, which should normally lead to melting thereof and interruption of the circuit. Such fuse should therefore protect the circuit against overloading.
• the secondary circuit merely serves for forced interruption of the primary circuit in the case, when the current in the first circuit does not exceed the nominal value, and the melting member is not interrupted due to excess current.
• said secondary circuit is activated, in which the temperature-depending resistor is exposed to the current, in which the heat is generated, which is thanks to said head-conductive relationship transferred to the melting member, which starts melting.
• numerous components are required for the purposes of functioning of said forced interruption.
• said melting member is in a heat-conductive relationship with said temperature-depending resistor, upon interruption of the primary circuit due to excess current it is generally possible that via said element, which is in contact with the melting member, a by-pass circuit is established at least for certain time period, through which an electric circuit is still established despite to interruption of the melting member as such.
• the present invention generally refers to a fuse with at least one melting member, which is suitable for interrupting each electric circuit extending there-through and which comprises a body consisting of electric insulating material and surrounding each disposable melting member, which is adjusted to each nominal value of the electric current and electrically connected to electric contact terminals, which are located on the external surface of said body of the fuse and via which said fuse is electrically connectable into each disposable primary electric circuit, which is then by means of said fuse protected against excess current, said fuse.
• such fuse further comprises a resistor, in particular a voltage dependent resistor i.e. a varistor, the electric resistance of which is inversely proportional to voltage and electric current to which it is exposed, wherein said resistor is located adjacent to said melting member and in a thermal-conductive relationship with said melting member, and wherein said resistor is electrically connected into a secondary electric circuit, which includes at least one switch, which can be activated in need and independently on situation within the primary electric circuit.
• a resistor in particular a voltage dependent resistor i.e. a varistor, the electric resistance of which is inversely proportional to voltage and electric current to which it is exposed
• said resistor is located adjacent to said melting member and in a thermal-conductive relationship with said melting member, and wherein said resistor is electrically connected into a secondary electric circuit, which includes at least one switch, which can be activated in need and independently on situation within the primary electric circuit.
• the invention further provides that said melting member and said resistor are located within said body of the fuse and are surrounded with a filler suitable for extinguishing of electric arc, in particular with silica.
• said secondary electric circuit, into which said resistor is included also comprises a switch, which is a remote-controlled switch.
• the invention still further provides that in addition to said electric contact terminals which are electrically connected with said melting member for the purposes of connecting the fuse into each disposable primary electric circuit, at least two further electric contact terminals are arranged on said body, in particular on the external surface thereof, which are intended for connecting said fuse into a secondary electric circuit.
• a fuse according to the invention may also comprise more than one melting member, wherein however each of disposable melting members is arranged in heat-conductive relationship with said resistor.
• the invention also refers to an electric circuit, which includes an electric voltage source and at least one load, and moreover comprises at least one fuse according to anyone of claims.
• said electric voltage source is preferably a direct voltage source.
• Fig. 1 is a schematically shown melting member of the fuse combined with a varistor
• Fig. 2 is a realistic scheme of the melting member according to Fig. 1;
• Fig. 3 is a schematically presented embodiment of a standardized CH-type fuse
• Fig. 4 is a schematically presented embodiment of a standardized NV-type fuse
• Fig. 5 is an electric circuit with integrated fuse according to the invention.
• a fuse 1 is foreseen according to the invention, which is furnished with at least one melting member (Figs. 1 and 2) and is capable to interrupt an electric circuit, into which it is integrated.
• a standardized CH-type fuse 1 with a single melting member 2 is presented in Fig. 3, while the NV-type fuse also with a single melting member is shown in Fig. 4.
• the fuse 1 comprising a body 10 consisting of electric insulating material and surrounding each disposable melting member 2 which is adjusted to each nominal value of the electric current I within each disposable circuit C and which is electrically connected with each disposable electric contact terminals 1 1, 12, which are located on said body 10, in the shown embodiments on the external surface thereof, and via which the fuse 1 is connectable to each primary electric circuit C, which is then by means of said fuse 1 protected against excess current.
• said fuse 1 also comprises a resistor 3, in particular a voltage dependent resistor 3, namely a varistor having a such characteristics that its resistance is inversely proportional to voltage and electric current to which it is exposed.
• Said resistor 3 is located adjacent to said single melting member 2, and is therefore arranged in a heat-conductive relationship with said melting member 2.
• said resistor 3 is electrically connected into a secondary electric circuit C", which is moreover furnished with at least one switch 4, which is optionally a remote-controlled one and can be in the need activated quite independently from each conditions in the primary electric circuit C, so that the current ⁇ occurs therein, which triggers heating of said varistor 3.
• said secondary circuit C" Prior to activation of said switch 4, said secondary circuit C" is interrupted, and the resistance of said varistor 3 is extremely high, so that the varistor 3 located adjacent to said melting member 2 does not have any impact to the situation within the primary circuit C.
• the excess current occurs within the primary circuit C, at least a portion of said melting member 2 is melted, and the fuse 1 is therefore functioning exactly on the same manner like any other known fuse of such type.
• the secondary circuit C is established and connected to the voltage source by means of activating said switch 4, upon which the current ⁇ starts energizing the resistor 3 and the resistance of said resistor 3 starts decreasing, by which the resistor 3 is then heated quickly and intensively.
• the heat, which is generated within said resistor 3 is then transferred to the melting member 2, upon which at least a portion thereof is melted, by which in emergency a forced interruption of said primary circuit C can be achieved, although the excess current has not occurred therein at all.
• the invention provides that the melting member 2 and the resistor 3 are both located within the body 10 of said fuse 1 and surrounded with a filler which is suitable for reducing effects of electric arc i.e. for extinguishing thereof, in particular with silica.
• each disposable melting member 2 in addition to said electric contact terminals 1 1, 12 which are electrically connected with the melting member 2 for the purposes of connecting the fuse 1 into a primary circuit C, at least two additional electric contact terminals 13', 13" are located on the external surface 10 of the fuse 1 (Figs. 3 and 4), which are electrically connected with said resistor 3 and are intended for connection of the fuse 1 into the secondary electric circuit C".
• the fuse 1 is used for protecting an electric circuit with high nominal current value, then at least two melting members 2 ought to be used. In such cases, each disposable melting member 2 must be arranged in the previously mentioned heat-conductive relationship with the resistor 3.
• the invention also refers to an electric circuit, which includes at least a voltage source 5, in particular a direct voltage source, at least one load 6, and also at least one fuse 1 characterized by previously disclosed features.

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• Fuses (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (2)

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ID=49958652

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (2)

• 2013
  • 2013-10-21 WO PCT/SI2013/000060 patent/WO2014065763A2/en active Application Filing
  • 2013-10-21 PL PL13821533T patent/PL2912675T3/pl unknown
  • 2013-10-21 EP EP13821533.0A patent/EP2912675B1/de not_active Not-in-force

Patent Citations (2)

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