Abstract: A semiconductor plate having an epitaxial layer of a conductivity type opposite to that of the substrate on which it is formed has a depression, including one or more elongate channels. The depression is etched into a depth passing entirely through the epitaxial layer to isolate at least one tongue extending from a tongue pedestal into the etched depression and having parallel major sides which are perpendicular to the principal planes of the semiconductor plate. The tongue is under-etched so that it will be free to vibrate by motion in directions parallel to the principal planes of the plate. One of the major sides of the tongue faces a stationary electrode across a gap and the electrode and the tongue are insulated from each other, at least in one embodiment, by the fact that the etched depression extends all the way through the epitaxial layer in its depth.

Abstract: An electronic circuit device having a monolithic integrated power transistor is disclosed that comprises a parallel connection of a plurality of individual partial transistors (1, 2, 3, . . . , n). In order to stabilize the distribution of the sum current to the individual partial transistors (1, 2, 3, . . . , n) resistors (41, 42, 43, . . . 4n) are provided in their emitter lines. At least one of the resistors (41, 42, 43, . . . 4n) in the emitter lines of the partial transistors (1, 2, 3, . . . , n) serves as measurement resistor for producing a signal voltage proportional to the current to provide an electronic circuit device having current regulation or current limiting, as shown in FIG. 2.

Abstract: A method and apparatus for checking the concentricity of a pneumatic vehicle tire that during operation has its beam portions mounted on the radially inner periphery of a wheel rim. The apparatus includes a two-part test rim, the two rim ring sections of which are axially movable. Disposed against the test rim is a tire that is to be checked, with this tire being manufactured with trapezoidally axially outwardly directed sidewalls, and with the tire being disposed against the rim ring sections in this trapezoidal form. Bead-receiving rings are moved axially from the outside against the axially moved-apart rim ring sections. These bead-receiving rings fold-over the sidewalls and bring them, in a rim-seating position, into contact against the rim ring section. The tire is secured in position between the rim ring sections and the bead-receiving rings.

Abstract: A filler ring, made of rubber or synthetic material, for a vehicle wheel and pneumatic tire assembly where the beads of the tire are mounted on the radially inner periphery of a wheel rim next to essentially radially inwardly extending rim flanges. The filler ring covers a space located axially inwardly of a rim flange. The filler ring includes at least two planes of circumferential hollow chambers, with the planes of hollow chambers being superimposed on one another in a radial direction, and with at least two hollow chambers, which are successively arranged in an axial direction, being provided in each of the planes of such hollow chambers.