Abstract: Dry plasma etching of a plurality of planar thin-film semiconductor wafers is effected simultaneously and uniformly in a relatively small chamber enveloping a vertically-stacked array of laminar electrode sub-assemblies each of which includes a pair of oppositely-excited electrode plates tightly sandwiching a solid insulating layer of dielectric material, the parallel sub-assemblies being vertically separated to subdivide the chamber into a plurality of reactor regions where RF discharges can excite a normally inert ambient gas to develop reactive plasma for simultaneous planar plasma etching or reactive ion etching (RIE) of all wafers within the several regions.

Abstract: In a refrigerated beverage dispenser having a plurality of coplanar circular cooling plates closing the bottoms of an array of beverage bowls, each concentric turn of a single multi-turn sinuous coiling of evaporator tubing is bonded in intimate heat-exchange relationships with all of the cooling plates and directs flow of the refrigerant serially across and part way around each cooling plate, and back, in succession. Tubing which interconnects across the spaces between adjacent cooling plates is clustered, to promote maximum arcuate spanning of the plates by those more active portions of the tubing best disposed to provide the cooling.

Abstract: Operator access to the zone at which workpieces are struck in a drop hammer is temporarily but reliably blocked by a sturdy mechanical guard throughout every period when the hammer may commence and complete its fall; a unique physical linkage, between the guard and a safety-dog lever which must be manually turned in order to release the hammer, insures that the safety guard must have been shifted from an out-of-the-way position into a protective orientation before the hammer can drop.

Abstract: Servo control of a butterfly valve or the like, in which fluid flow is inherently non-linearly related to angular orientations of a vane or plug member, is effected through a function-generator mechanism interposed to render the system transfer function substantially constant. A function generator serving those purposes includes a mechanical cam-and-follower unit through which valve-controlling angular movements are maintained in a cosine-related slaving with angular movements of the rotor of an electrical servo motor.

Abstract: Regulation of pressure at which fluid is allowed to flow is determined by a device which is externally substantially monolithic in character and includes internal components assembled within it through an end coupling. Relatively low height and small girth are promoted by unique communication of internal flow around the edge of a diaphragm from one side and which is distinctively sealed only along the opposite side.

Abstract: Auxiliary heat-sink attachments which promote dissipation of heat from electronic solid-state devices and the like are secured with such devices and with associated printed-circuit boards by way of accessory fastenings with which they form a sub-assembly wave-solderable in pre-spaced relation to the board.

Abstract: A fixed frequency pulse width modulated current fed inverter power supply with imbalance compensation provided by means of a primary inductor in the input circuit. Energy is coupled between the primary inductor in the input and secondary inductor windings in the output circuits to provide a balanced power supply with good efficiency.