Abstract: A contactor has two contact elements (1, 2) each having a contact member (3, 4) adapted to bear with the contact side (5, 6) thereof against a said contact side of the other contact member for enabling an electric current to flow between said to contact elements. The contact sides of both contact members are provided with serration's (11, 12) extending so that elongated ridge-like peaks (13) of serration's of one said contact side intersect such peaks of the other said contact side while forming a plurality of spots of mutual contact of these contact sides distributed over the area of said contact sides.

Abstract: A contactor has two contact elements (1, 2) each having a contact member (3, 4) adapted to bear with the contact side (5, 6) thereof against a said contact side of the other contact member for enabling an electric current to flow between said to contact elements. The contact sides of both contact members are provided with serration's (11, 12) extending so that elongated ridge-like peaks (13) of serration's of one said contact side intersect such peaks of the other said contact side while forming a plurality of spots of mutual contact of these contact sides distributed over the area of said contact sides.

Abstract: A compressor includes a compressor wheel, a diffuser and a device for the wet cleaning of the diffuser of a compressor, the diffuser being arranged downstream of the compressor wheel in the flow direction of the medium to be compressed. The device includes an arrangement for injecting a liquid, which is arranged in such a way that the liquid can be introduced, downstream of the compressor wheel, to the diffuser. The diffuser has at least partially a non-stick coating. A device of this type is suitable for removing deep-seated deposits from the surface of the diffuser.

Abstract: A compressor comprises a compressor wheel, a diffuser and a device for the wet cleaning of the diffuser of a compressor, the diffuser being arranged downstream of the compressor wheel in the flow direction of the medium to be compressed. The device comprises means for injecting a liquid, which are arranged in such a way that the liquid can be introduced, downstream of the compressor wheel, to the diffuser. The diffuser has at least partially a non-stick coating. A device of this type is suitable for removing deep-seated deposits from the surface of the diffuser.

Abstract: The subject of the invention is a passive indicator of voltage presence used to indicate voltage in electrical conductors, electrically powered devices, power distribution devices and transmission lines of high, medium and low voltage. The indicator according to the invention is characterized in that it has form of a multilayer plate comprising two electrically conductive layers (2, 4) and an intermediate layer (3) of a structure manifesting electrooptical properties, located between them, wherein the intermediate layer is a display element of the indicator, while the conductive layers are electrodes of that display element and they are electrically connected by means of a diode (5), and one of the conductive layers is at least partially transparent.

Abstract: The invention relates to a novel method of producing a resistor device comprising a PTC-polymer element 2 and a varistor element 4. Both elements are molded in a common molding process using one common mold. Preferred is co-injection molding. The invention further relates to the resistor device thus produced and a current limit means including the resistor device and a switch (FIG. 4).

Abstract: The invention relates to an apparatus for limiting an electrical current by using a PTC resistor being monitored by a monitor circuit. According to the invention, the monitor circuit issues a signal only after detecting the status of the PTC resistor for a defined time period after a PTC resistance change.

Abstract: The invention relates to a novel method of producing a resistor device comprising a PTC-polymer element 2 and a varistor element 4. Both elements are moulded in a common moulding process using one common mould. Preferred is co-injection moulding. The invention further relates to the resistor device thus produced and a current limit means including the resistor device and a switch (FIG. 4).

Abstract: A fuse has a fuse element (6), composed of silver, with constrictions (7) which follow one another at regular intervals, and which fuse element makes contact with a combustible element (8), preferably over its entire length. The combustible element (8) is composed of a combustion compound, which is essentially of a fuel such as guanidine or a guanidine derivative and a metal such as Mg or Al and an oxidant such as KNO3, NaNO3, NH4NO3, KClO4, NaClO4, KMnO4, the proportion of which is overstoichiometric by a factor of at least 1.1, and preferably of at least 10. The combustible compound also preferably contains a binding agent such as paraffin, a thermoplastic or an elastomer, so that it can be extruded. It has an ignition temperature of between 160° C. and 260° C. and emits more than 200 J/g of heat, so that it ignites even in the event of small overcurrents and melts the entire length of the fuse element (6).

Abstract: The invention relates to an electric device with a PTC polymer element having a constriction. The constriction defines a web extending in a main current direction over a length longer than in the prior art, namely longer than 5 mm, preferably longer than 15 mm. Further, the aperture angle of the PTC polymer material at the ends of the web is larger than 100°. A preferred choice of material is given, further. The invention achieves very high voltage-withstand capabilities.

Abstract: The invention relates to an electrical device with a PTC polymer element having a constriction. The constriction defines a web extending in a main current direction over a length longer than in the prior art, namely longer than 5 mm, preferably longer than 15 mm. Further, the aperture angle of the PTC polymer material at the ends of the web is larger than 100°. A preferred choice of material is given, further. The invention achieves very high voltage-withstand capabilities.

Abstract: A protective element for protecting in particular an electric motor against overload currents includes in a polymer matrix, preferably ETFE, for example 40% (by volume) of a first powdered filler of a conductive material, preferably TiB2, so that, as in the case of a PTC element, the resistance increases abruptly at a switching temperature corresponding to the melting temperature of the polymer. Also added are 20% (by volume) of a second powdered filler, a phase transition material which, at a critical temperature below the switching temperature, undergoes a phase transition in which it absorbs heat of transformation. As a result, the response time (T) of the protective element is notably extended in a range of the overload current factor (F) corresponding to higher permissible motor starting currents.

Abstract: A fuse has a fuse element (6), for example composed of silver, with constrictions (7) which follow one another at regular intervals, and which fuse element makes contact with a combustible element (8), preferably over its entire length. Said combustible element (8) is composed of a combustion compound, which consists essentially of a fuel such as guanidine or a guanidine derivative and a metal such as Mg or Al and an oxidant such as KNO3, NaNO3, NH4NO3, KClO4, NaClO4, KMnO4, the proportion of which is overstoichiometric by a factor of at least 1.1, and preferably of at least 10. The combustible compound also preferably contains a binding agent such as paraffin, a thermoplastic or an elastomer, so that it can be extruded. It has an ignition temperature of between 160° C. and 260° C. and emits more than 200 J/g of heat, so that it ignites even in the event of small overcurrents and melts the entire length of the fuse element (6).

Abstract: A description is given of a PTC polymer element (1) as part of an electrical component with a novel structure in which aperture angles (&agr;) on both sides of constrictions (2) in the PTC polymer material are at least 100°. As a result, an improved response behavior can be achieved, and, in connection with further features, the construction of PTC polymer elements which are more rapid, capable of carrying greater currents and have higher dielectric strengths is possible.

Abstract: The resistor body of a nonlinear resistor element having PTC characteristics includes a pulverulent first filler, whose material, e.g. TiB.sub.2, TiC, VC, WC, ZrBr.sub.2, MoSi.sub.2, has a specific conductivity of at most 10.sup.-3 .OMEGA.cm and in which the particle sizes are between 10 and 40.mu., and also, in order to improve the voltage sustaining capability by extending the switching zone and to achieve uniform energy absorption, includes a likewise pulverulent second filler having varistor characteristics and particle sizes between 50 and 200.mu., whose specific resistance at field strengths .gtoreq.2000 V/cm such as occur in the switching region of the resistor element and above, is at most 50 .OMEGA.cm, preferably at most 15 .OMEGA.cm, the fillers being embedded in a matrix made of a thermoplastic, in particular HD polyethylene or a thermoset. The average particle size of the second filler should exceed that of the first filler by a factor of from 2 to 5.

Abstract: A power switching apparatus is disclosed which has an electrical conductor to which high voltage can be applied. A series of circuits formed by a switching point and a current-limiting element which contains PTC thermistors and varistors is arranged in the cable run of the electrical conductor. An apparatus for operating the switching point interacts with the current-limiting element. The current-limiting element has n (where n is a natural number greater than 1) series-connected parallel circuits each having at least one PTC thermistor and at least one varistor connected in parallel with it. A current sensor arranged in the cable run of the electrical conductor or those connections of one of the PTC thermistors and of the varistor connected in parallel with it which are interconnected at two junction points in one of the parallel circuits are operatively connected to the input of the operating apparatus.

Abstract: The current-limiting resistor has two connection electrodes (1, 2) which are arranged parallel to one another as well as a resistance body (3) which has PTC behavior and with which large-area contact is made by the connection electrodes (1, 2). A varistor (40) is in electrically conductive contact with the resistance body (3). The resistance body (3) contains two contact areas (50, 51) as well as a response point (60) which is connected in parallel with the varistor (40) via the two contact areas (50, 51) and implements a PTC transition above a threshold value of a current flowing through the resistor.Since the resistance body effects the electrical contact with the varistor (40) in the case of this resistor, no metal connection electrodes are required for the varistor. At the same time, due to the outward displacement of the response point (60) away from the varistor (40), the operational reliability of the resistor is considerably improved.