Abstract: A bonded insulator flexural transducer for use in sonar applications includes a hollow metal tube having an inner surface, a segmented ceramic electromechanical driver disposed along an inner surface of the tube and a bonded insulator disposed between the segmented driver and the metal tube. The bonded insulator includes a high dielectric strength film, a layer of a binding fiber material, and a layer of epoxy. The dielectric film provides the electrical isolation between the driver and the shell and the binding fiber material provides a reliable bond by effectively trapping the epoxy between the driver and shell.

Abstract: 1. An electronic control circuit, a plate supply for said circuit, an eleonic grid-controlled power tube controlled through its grid by the output of said control circuit, a translating device energized by said power tube in response to the output of said control circuit, a condenser connected to serve as a plate supply source for said power tube, circuit connections for charging said condenser from said first plate supply, an unsymmetrical resistance in said circuit connections arranged to offer a high impedance to passage of charging current from said first plate supply to said condenser, but to offer low impedance to discharge of said condenser into the plate supply, whereby upon reduction of said plate supply voltage below a safe operating level, said condenser voltage will be rapidly reduced to a value below the operating value.

Abstract: A process is provided for coating a given surface of a heat sensitive metal article (e.g., thermally massive aluminum) with a high-cure-temperatureating-forming-powder. A first oven heating step elevates the metal article's temperature to a predetermined preheat cycle high-limit-of-heat-load-temperature. After a first predetermined period of time, the metal alloy article is withdrawn from the oven. A high-cure-temperature-coating-forming-powder is then sprayed onto the given surface of the metal article. The spraying, comprising first and second spray sequences, is initiated essentially immediately after withdrawal of the metal article from the oven. The first spray sequence is a single group of spray passes that applies a coating layer to fill the pores in the given surface with heat melted high-cure-temperature-coating-forming-powder. The second spray sequence builds up the total thickness of coating.