Abstract:
Method and apparatus for identifying and determining the energization status of a cable having a conductive neutral member and an internal resistive screen layer involving probes radially movable relative to the cable to contact the neutral member and the internal resistive screen. Narrow-band AC signals and resistance measurements are utilized for self-testing and for cable testing. A microprocessor controls probe-heating in the advancing of probes through plastic sheath to reach the neutral wire and resistive screen layer. Resistance measurements made under control of the microprocessor are monitored with probe advance. Oscillators provide two signals of different frequencies, one of which is that of the power being transmitted through the cable, to provide distinctive signals indicative of cable energization status.
Abstract:
A method and apparatus for attracting insects, especially black flies, sand flies and mosquitoes, in which the physical effects associated with the skin areas of prey-animals are simulated. Basic elements of a first embodiment of the apparatus include warmed elastic-walled holders of pulsed fluid which may be in the form of elastic tubing through which warm fluid flows in pulses arranged to produce various physical effects. Power for fluid heating and pulsing action may be provided by solar electrical, mechanical, nuclear, chemical or other source. Basic elements of a second embodiment of the apparatus include a weak spring suspended from a support and coupled to a vibration generator. The spring includes a deformable skin-like membrane therearound. Vibration is imparted to the spring and transmitted to the membrane to produce physical effects associated with movement of a skin surface of a prey animal. A heater may also be provided to heat the skin-like surface. A still further embodiment includes an exciter and a traveling wave transmitting member. The exciter is moved relative to the traveling wave transmitting member to impart a traveling wave therein to attract insects to the apparatus. Killing of insects or collection of live or dead insects may be accomplished by trapping or execution electrically, mechanically, or chemically. In a preferred embodiment, the wave transmitting member and collector/killer element are combined into an integral unit. This unit may be removed and replaced as necessary.
Abstract:
A method and system for determining the status of power distribution cables which involves the removal of a plug from the sheath which is tiny relative to the size of the cable to expose an area of resistive material which may be probed to detect the presence or absence of a signal of predetermined frequency. The apparatus is equipped with self-testing circuits as well as circuits for determining resistance between the resistive layer and the sheath, whereby positive identification of the cable to be tested is assured. The apparatus is clamped directly to the cable and is controlled from a remote location, which protects the operator of the equipment. The plug removed from the sheath is cut and extracted by a tool which is also subject to remote control by the operator.
Abstract:
The inner surface of a barrel for a traveling wave tube is formed with a set of tracks extending parallel to the longitudinal axis of the barrel. The rods supporting the traveling wave tube circuit assembly are supported in the tracks. The tracks are formed by forcing a tool having track-forming elements through the barrel, or a succession of ever-larger tools may be used to first form and then gradually enlarge the tracks.
Abstract:
Current injection electrostatic discharge equipment that includes a discharge capacitor connected to the input terminal of a sulfur-hexafluoride filled relay for selectively applying a current discharge to a test tip, the wave shape of the current discharge being highly repeatable.
Abstract:
The present invention concerns a method for triggering certain high voltage electronic, gas discharge switches that are a novel type of high power thyratron. In this invention, triggering of switches of the so-called "pseudospark thyratron" type (a type of cold cathode thyratron) is enhanced by the inclusion of a very small, hot thermiionic trigger switch or cathode, separate and isolated from the main switch electrodes, to initiate the triggering discharge. The trigger cathode is protected from destruction by the main discharge current through the switch by mechanically and electrically isolating it from further participation in the discharge once the triggering process has been initiated.