Abstract: A device is disclosed for testing electrical circuits. More particularly, a device is disclosed which operates to give a visual indication of both continuity and a live circuit path. The device includes a hollow casing having a conductive probe mounted at one end. A ground wire is connected to the opposed end of the casing. The testing circuit of the subject invention is disposed within the casing. The testing circuit includes a first light-emitting diode (LED) connected in a manner to pass electrical current between the probe and the ground. A second LED is provided which is connected in opposite polarity. A battery is provided to power the second LED. The battery and second LED are connected in parallel with the first LED. In operation, the first LED will be illuminated when there is a live circuit, while the second LED will be illuminated if the circuit is continuous. Neither of the LED's will be illuminated if the circuit is broken.

Abstract: An apparatus and method for removing burrs and other roughage from stamped, milled and cast metallic articles. A conical combustion chamber is provided with a spiral groove which creates a turbulent flow for an ignited combustible mixture, which turbulence transforms the process from combustion to detonation. The detonated gaseous mixture is directed down the conical combustion chamber in expanding fashion to the articles which are to be de-burred, which articles are stored in a receptacle in axial alignment with the conical-shaped combustion chamber. During detonation, the burrs and other roughage are removed from the articles, while the remainder of each article is kept in tact.

Abstract: A pressure transducer is provided with a housing in which is mounted a pressure sensitive piezoelectric crystal for converting pressure changes of a rapidly moving gas to electrical signals. The crystal is mounted within the housing in a floating manner by a brass damping bar which damps extraneous acoustic oscillations. The hollow interior of the housing is filled with beeswax that surrounds the damping bar and the piezoelectric crystal, so that any parasitic oscillations arising from housing wall are damped.