Abstract: Systems and methods for braking a power tool using a stamped brake resistor. The power tool includes a motor, a trigger configured to be actuated, and a brake switch coupled to the motor. A brake resistor assembly is selectively coupled to the motor via the brake switch and includes a stamped brake resistor. The stamped brake resistor includes a terminal portion and a resistive portion. The resistive portion includes a planar serpentine path. A controller including an electronic processor and a memory is coupled to the trigger, the motor, and the brake switch, and is configured to control power delivered to the motor based on a position of the trigger, determine to brake the motor during operation of the motor, and activate, in response to determining to brake the motor, the brake switch to connect the stamped brake resistor to the motor.

Abstract: A liquid-cooled resistor device including a block having a liquid inlet, a liquid outlet, and a cavity. The cavity is provided with a liquid flow path between the liquid inlet and the liquid outlet. The cavity can have an open side which is closed by a thermally conductive, electrically insulating flat layer. The flat layer can further support a flat resistor, the main plane of each being in parallel. The device can further include an electrically insulating blocking plate, fastenable to the block. The blocking plate can face the resistor to block the resistor on the flat layer. The device can also include a elastic pressing device positioned and configured to force the flat layer against the resistor.

Abstract: A liquid-cooled resistor device including a block having a liquid inlet, a liquid outlet, and a cavity. The cavity is provided with a liquid flow path between the liquid inlet and the liquid outlet. The cavity can have an open side which is closed by a thermally conductive, electrically insulating flat layer. The flat layer can further support a flat resistor, the main plane of each being in parallel. The device can further include an electrically insulating blocking plate, fastenable to the block. The blocking plate can face the resistor to block the resistor on the flat layer. The device can also include a elastic pressing device positioned and configured to force the flat layer against the resistor.

Abstract: A smart link in a power delivery system includes an insulator, which electrically isolates a power line, and a switchable conductance placed in parallel with the insulator. The switchable conductance includes switchgear for sourcing, sinking, and/or dispatching real and/or reactive power on the power line to dynamically in response to dynamic loading, transient voltages and/or currents, and phase conditions or other conditions on the power line.

Abstract: A resistor assembly and method of assembling a resistor to a coupling, comprises providing a resistor having a first end and a second end, the resistor being tubular in shape and providing a coupling housing having an open end for receiving the first end of the resistor, the coupling housing including a sealing member, a retainer, and a support washer. The retainer is interposed between the support washer and sealing member. The first end of the resistor is inserted into the open end of the coupling housing. The tube is rotated within the coupling housing so that the resistor is in sealing engagement with the sealing member and retained by retaining member.

Abstract: A resistor assembly and method of assembling a resistor to a coupling, comprises providing a resistor having a first end and a second end, the resistor being tubular in shape and providing a coupling housing having an open end for receiving the first end of the resistor, the coupling housing including a sealing member, a retainer, and a support washer. The retainer is interposed between the support washer and sealing member. The first end of the resistor is inserted into the open end of the coupling housing. The tube is rotated within the coupling housing so that the resistor is in sealing engagement with the sealing member and retained by retaining member.

Abstract: A high power resistor includes a resistance element with first and second leads extending out from the opposite ends thereof. A heat sink of dielectric material is in heat conducting relation to the resistance element. The heat conducting relationship of the resistance element and the heat sink render the resistance element capable of operating as a resistor between the temperatures of ?65° C. to +275° C. The heat sink is adhered to the resistance element and a molding compound is molded around the resistance element.

Abstract: An inductor obtained by laminating a plurality of ceramic layers having an internal coil conductor, and a thermistor obtained by laminating a plurality of ceramic layers having internal electrodes and having a predetermined resistance-temperature characteristic are laminated via an intermediate insulating layer. Both ends of the internal coil conductor of the inductor and the internal electrodes of the thermistor are connected to a pair of external electrodes. Thus, the inductor and the thermistor are connected in parallel.

Abstract: PTC thermistors are used in reversible short circuit current limiters, in particular in series connection with electrical valves and/or capacitors. An electrically insulated, thermally conductive insulation or ceramic layer (20) is in contact electrically and with good thermal conduction via a first main surface with a metallic cooling element (25). A second main surface of the ceramic layer (20), opposite the first main surface, is covered with an electrically insulating thermal-conduction layer (21) having a thickness in the range from 10 .mu.m-100 .mu.m. Meandering tracks (16) of the resistive body of the PTC thermistor (5) are pressed between this thermal conduction layer (21) and an electrically insulating, preferably thermally conductive, flexible high-temperature stable polymer film (22). In order to provide pressure, a pressure compensation cushion (23) on which a force (F) orthogonal to the second main surface of the ceramic layer (20) acts, may be provided.

Abstract: A reversible short circuit current limiter which has at least one PTC thermistor connected in parallel with a shunt impedance branch, and is connected in series with at least one capacitor or a capacitor bank of the DC intermediate circuit. The short circuit current limiter may be arranged in the DC intermediate circuit or in the current convertor. A diode may be connected in the reverse-bias direction of a short circuit path in parallel with the PTC thermistor. The shunt impedance branch has a varistor connected in series with an ohmic resistor or a PTC thermistor and, if appropriate, an inductor. Structures of metal-based nonblocking PTC thermistors are specified.

Abstract: A liquid cooled, heavy duty resistor including a housing and a resistor element. The resistor element is arranged inside a chamber defined by the housing. The resistor element and the housing form a rectangular duct through which a cooling liquid flows from an inlet to an outlet. The chamber is defined by two insulating plates and an insulating ring. The resistor element is a bifilar wound spiral strip conductor and is clamped between two insulating plates such that the cooling liquid flows through the rectangular duct. The liquid cooled, heavy duty resistor can remove a high dissipated power in a small space, has low inductance, and has a low resistance value.

Abstract: A liquid-cooled high-load resistor includes an element carrier having an inlet and an outlet, a break-through and a first and second electrical terminal connection, and one resistor element, respectively, on its flat sides. The active parts of the resistor elements are electrically connected in series by means of the break-through in the element carrier and are electroconductively connected to an electrical terminal connection of the element carrier. The liquid-cooled high-load resistor further includes two covers that each cover a flat side of the element carrier, to form an enclosed space between the cover and the flat side of the element carrier. The enclosed space is subdivided so as to provide a free space in the area of the inlet, the outlet, and the break-through, and to provide a cooling channel that embeds the active part of the resistor element.

Abstract: A muzzle arc suppressor allowing rapid repetitive refiring of railguns. A varistor or varistors electrically connect the muzzle ends of a railgun. Resistive inserts are placed inside the rails near the muzzle end. When the railgun projectile reaches the resistive inserts, the voltage across the varistor increases to above the varistor breakdown voltage, thereby commutating the railgun current from the projectile to the varistor, and dissipating excess magnetic energy through resistance heating of the varistor. The varistor is preferably made of zinc oxide, which is temperature invariant over a wide temperature range. The varistor may be pre-cooled to increase its energy absorbtion ability. A specific embodiment of the arc suppressor has the zinc oxide varistor conformably shaped to surround the rails. The conformably shaped varistor includes coolant passages.

Abstract: A high power density, low corona resistor comprises a dielectric thermally conductive substrate having upper and lower surfaces and having a resistance element mounted on the upper surface thereof. The resistance element comprises a thin film of electrically conductive material. A pair of electrical leads are electrically connected to the resistance element and extend upwardly therefrom. An electrically insulative material covers the resistance element to provide physical and structural protection to the resistance element and the pair of leads. An electrically conductive sheet is operatively secured to the lower surface of the substrate and is in intimate contact therewith so as to substantially fill any microscopic indentations in the lower surface of the substrate thereby substantially eliminating voids between the lower surface of the substrate and the conductive sheet.

Abstract: A high voltage semiconductor valve has a plurality of electrically series-connected semiconductor elements, for example thyristors or diodes. These are designed for pressure contact connection and for double-sided cooling and are arranged alternately with liquid cooling bodies in a stack. At least some of the resistors included in the voltage divider of the valve are arranged with their resistive portions located in a passage in the cooling body between the contact surfaces for the two adjacent semiconductor elements.

Abstract: A cooled resistor pack for a dynamoelectric machine wherein cooling water is passed through ducts in a conductive block and plurality of connectors are mechanically attached to the conductive block but electrically insulated therefrom and nichrome wires of varying length and varying in number electrically join the connectors to the conductive block and individually insulated brush segments, which have individual strands and the brush segments are connected to separate connectors in such a manner that the resistance between the brush segments and the block decreases from the trailing end segments to the leading end segments of the brush.

Abstract: A liquid-cooled power resistor contains at least one resistive conductor which is arranged in a closed housing directly in de-ionized water employed as the cooling liquid or coolant. The resistive conductor is advantageously secured in diaphragms which not only serve as holding facilities for holding the resistive conductor, but also deflect or turn the cooling liquid. The resistive conductor is normally connected to two terminal pins. There also can be used a third terminal pin which taps the center or mid-point of the resistive conductor, so that there are available two ohmic values of the power resistor. The power resistor ensures for an effective and uniform removal of heat or thermal energy and possesses a high thermal capacity. The arrangement has a low inductance. The power resistor is particularly suitable for the wiring of thyristors in static converter installations.

Abstract: An electric resistor coolant device is provided which comprises a lined tank for inclusion of water or other coolant containing a water inlet and outlet in which is submerged one or more electric resistor coils. The electric resistor coils are utilized in the load testing of certain electric power supply sources. Heat generated in the resistors by the electrical charge is carried away by the water contained in the tank, thereby increasing the capacity of the coils to carry electric current.

Abstract: A liquid-cooled electrical assembly containing an arrangement for cooling at least one electrical component under current flow. In this assembly, liquid coolant flows into an inlet in the cooling arrangement and the heated-up coolant is removed through an outlet. In order to increase the power handling capacity of such an arrangement over that of known arrangements having similar dimensions, a cooler is constructed from sheet-like or layer-like cooling elements, each of which have an entrance or inlet opening and an exit or outlet opening for the liquid coolant. The cooling elements are stacked together in alternating fashion with the electrical components so that the entrance openings and exit openings of the cooling elements are in direct connection with the inlet and outlet of the whole cooler. This kind of assembly will find many preferred applications when they are constructed as resistors or power semiconductors.

Abstract: A resistor type arc welding machine comprises a housing capable of containing a cooling liquid; first and second main resistors serially connected to each other, the free end of the first resistor being connected to the current line of an alternating current source and the free end of the second resistor being connected to a holder for a welding electrode; one or more taps from intermediate points along said first and second main resistors, which taps may be connected, preferably through respective by-pass resistors, to the said holder instead of the free end of said second main resistor, to provide higher amperage outlets; and a direct line whose first end is connected to ground and whose second end is connected to the work piece to be welded, in order to complete the electrical circuit and to produce the welding arc; the above mentioned main resistors being arranged in an open and perforate support fixed in said housing such that the resistors will be continuously and completely submerged in the cooling liq

Abstract: An improved electrical heating element is constructed in such a manner as to increase the amount of electrical wire per unit space available for plug-type convection heating units. The plug uses a rectangular-shaped frame which has a plurality of spool covered rods evenly spaced along the length of the frames and extending across the width. The spools are slidably attached over the rods and have an insulated spacer on each side of the spool. The heating wire has alternate coiled and straight sections and is wound over and held to each spool by a retention wire and a groove in the spool. The rods are spaced at such a distance from each other that there is a straight section of heating wire at each spool with the coiled sections located between adjacent rods.

Abstract: Air is pumped from an upper chamber in a cylindrical housing through parallel groups of Ni-Cr steel heating tubes to a lower chamber communicating with a carbon-dioxide adsorber in an air-rectification system. The tube groups are suspended at their upper ends from respective Al.sub.2 O.sub.3 -ceramic holder plates seated on flanges projecting into respective openings of a carrier plate in turn removably fastened to the inside of the housing. The tubes in each group are connected in series with one another to a voltage source, the lower ends of the tubes in a group being gripped by a form-fitted ceramic spacer slidably inserted into a pipe section aligned in a support plate with an associated opening in the upper carrier plate, thereby ensuring the electrical insulation of the tubes. The holder plates and the openings are shaped as circles or as circular sections.

Abstract: High-use-temperature electrical contacts for carbon-containing glasses which include a soft, glass-adherent metal layer in contact with the carbon phase in the glass and a compression electrode positioned over the metal layer which maintains compressive stress between the layer and the glass at temperatures up to and including the contact use temperature are described. Electrical circuit elements comprising one or more of such contacts offer stable electrical performance after repeated cycling to high temperatures.

Abstract: The installation for heating liquid and gaseous media comprises at least one heating unit which consists of an insulating body whose external surface is coated with a conducting film. The heating unit is made as a combination of variable-section containers interconnected in series. Buses are used for delivering electric voltage to the conducting film.The installation according to the invention increases the efficiency of heating extra-pure liquid and gaseous media three to four times, reduces the consumption of electric power three to four times and requires only a small amount of costly metals for its manufacture.

Abstract: A liquid rheostat includes a conductive element which surrounds multiple electrodes. The element provides a multiplicity of current paths between the electrodes at a given depth of electrolyte solution thus decreasing current concentration of the electrodes. In order to further decrease current concentration, cylindrical electrodes are used. In a second embodiment, the liquid rheostat and an electrolyte storage container are disposed so as to surround a fluid transport pipe of a pumping system, the fluid being transported in the pipe serving to cool the electrolyte. The rheostat and storage container combined with the pipe provide a compact arrangement for saving space in a pump installation.

Abstract: A resistor with a heat sink, particularly adapted for use as a current limiter in an electrical system, such as a power transmission system. The resistor comprises a hollow tube formed of metal which offers resistance to the passage of electrical current, the tube being of a length sufficient to provide the electrical resistance for a given application. The heat sink comprises a material having a high specific heat, the material being contained within the tube and adapted to absorb heat generated by the resistance of the tube to passage of electrical current.