Abstract: A power resistor having much improved heat dissipation ability to an underlying heatsink because a step or protuberance is provided that cooperates with the mounting bolt or screw to largely nullify the effects of molding-caused camber or curvature.

Abstract: A method of soldering leads to electrical elements, such as resistors, in which a ribbon of solder, having a coating of flux, is sandwiched between a plurality of electrical elements and a plurality of leads. Hydrogen flames then cut the ribbon at points between the electrical elements and also between the leads. The hydrogen flames are then directed at the leads to melt the solder and cause extending portions of the ribbons to be drawn towards the leads.

Abstract: The power resistor has a metal housing and heatsink, the bottom wall of which is planar and has a bolt hole therethrough for tight securing of the resistor to a chassis. A planar film-type power resistor is mounted in the housing and encapsulated therein, being held close to the bottom wall of the housing. Heat from the film-type resistor passes through the bottom wall into the chassis, the result being that the power rating of the resistor is high. The metal housing is die-cast of a zinc alloy, at extremely low cost yet with substantially the same heat-transmission characteristic as that of conventional die-castable aluminum alloys.

Abstract: A film-type cylindrical resistor in which the end caps fit over the environmentally protective coating. Both the resistive film and the environmentally protective coating are applied by screen printing. Termination films are provided at the ends of the resistive film, and are electrically contacted by the end caps. The method comprises screen printing the resistive and termination films, and the environmental coating, and then mounting the end caps by interference-fit connections.

Abstract: A method of making a high-voltage, noninductive, film-type resistor by providing on an insulating substrate a coating of resistive material. A laser beam is then operated to cut through the coating and remove portions so shaped that the remaining coating portions form a zigzag line. The laser cutting is so effected that each zig converges toward the adjacent zag at an angle sufficiently small that there is a major inductance-cancellation effect.

Abstract: A "silk screen" is provided with a patterned pervious portion the dimension of which, in the direction of screen movement, is substantially less than the circumference of the cylindrical substrate. The screen is then moved beneath a squeegee through a distance which is greater than the indicated dimension of the pattern but less than the substrate circumference, the result being that a thick film of resistive material is metered onto the substrate without any overlapping or smearing. The squeegee, at the end of the screen-printing stroke, is located at an impervious portion of the screen, so that even unspindled small-diameter ceramic substrates are disengaged from the screen with no sticking or smearing. Such cylindrical substrates are solid in order to be economical, and to permit zero moisture intrusion. It is a feature of the invention that such economical solid substrates can be used, and are driven solely by screen friction so that loading, unloading and other problems are minimized.