Abstract: A planar coil construction, especially adapted for use in a force-producing device such as a de-icer, includes first and second sheet-like members, each defined by a continuous electrical conductor having a plurality of turns and first and second ends. The first end of the first conductor defines an electrical input to the coil, while the second end of the second conductor defines an electrical output from the coil. The second end of the first conductor and the first end of the second conductor are electrically connected. The sheet-like members are superimposed such that current flow through adjacent turns of the conductors is in the same direction. Within each sheet-like member, adjacent conductors also have current flow in the same direction. The invention includes a technique for spacing the conductors by means of a dielectric layer, and a technique for encapsulating the sheet-like members.

Abstract: A planar coil construction, especially adapted for use in a force-producing device such as a de-icer, includes first and second sheet-like members, each defined by a continuous electrical conductor having a plurality of turns and first and second ends. The first end of the first conductor defines an electrical input to the coil, while the second end of the second conductor defines an electrical output from the coil. The second end of the first conductor and the first end of the second conductor are electrically connected. The sheet-like members are superimposed such that current flow through adjacent turns of the conductors is in the same direction. Within each sheet-like member, adjacent conductors also have current flow in the same direction. The invention includes a technique for spacing the conductors by means of a dielectric layer, and a technique for encapsulating the sheet-like members.

Abstract: An article and method for measuring the extent, location and rate of water vapor droplet impingements on various surfaces exposed to multi-dimensional and turbulent flow fields. The article and method are employed in a non-icing atmospheric environment, and the results are used to prognosticate not only the areas where ice would accumulate if the water droplets were supercooled but also the concentration thereof. The invention is accomplished by removably adhering a droplet impingement recorder (10) to a surface to be tested, such as an airfoil (20). The droplet impingement recorder (10) incorporates a water soluble gelatin coating (13) bonded to a substrate (11). Droplets suspended in the flow field impact upon the recording surface (18) of the droplet impingement recorder (10).