Abstract: A re-entrant, low-pressure, electrodeless lamp apparatus includes two identical re-entrant center conductors driven in quadrature, resulting in a matched lamp input impedance in both the off and on states nearly independent of incident microwave power.

Abstract: An improved radial type high voltage solid-state switch is essentially a gated diode switch (GDS) having two anode regions, two gate regions, a common cathode region, and a common shield region. The anodes, gates, cathode, and shield all have sides which are portions of concentric circles. The arc lengths and radii of the anode regions are less than the corresponding arc sides of the shield and cathode. This structure, which is a dual radial gated diode swtich (DRGDS), has lower on resistance than a conventional radial gated diode switch which has the same operating voltage range.

Abstract: This invention relates to a portable testing device which is used in a system having a host terminal, a plurality of secondary terminals, and a communication line interconnecting the host and secondary terminals for in-house communication. The transmission line includes a transmit line pair, a receive line pair, and a ground line. The testing device is operated in one of three modes which are selected via a switch on the device. The three modes of operation are:(1) Monitoring the transmit lines from the host and secondary terminals;(2) Performing "turn-around" functions with the host or secondary terminals; and(3) Performing "turn-around and load testing" with the host or secondary terminals.

Abstract: A radial type of high voltage solid-state switch is essentially a gated diode switch (GDS) with portions of the anode, cathode, shield, and gate regions being arc portions of concentric circles which have different radii. The arc length and radius of the arc portions of the anode are less than the corresponding parameters of the shield and cathode. This structure, which is denoted as a radial gated diode switch, RGDS, has lower on resistance than a standard GDS of the same area and distance between anode and shield regions.

Abstract: An electromagnetic discharge apparatus including an electrodeless lamp containing a fill material which emits light when subjected to a high frequency electric field. The lamp envelope is generally cylindrical. Power is coupled to the contents of the lamp by electrodes which encircle each end of the envelope and are spaced apart in the central region of the envelope to provide a capacitive gap between them. An inner coaxial conductor is connected to one of the electrodes and an outer conductor is connected to the other electrode by way of a conductive shielding member which encircles the lamp and the electrodes. A heating arrangement may be provided to maintain the temperature and thus the pressure of the fill material within the envelope constant.

Abstract: An electromagnetic discharge apparatus including an electrodeless lamp containing a fill material which emit light when subjected to a high frequency electric field. Power is coupled to the contents of the lamp by a coupling fixture having an outer conductor of conductive mesh and an inner conductor. The electrodeless lamp is mounted between two electrodes, one from the inner conductor and one from the outer conductor which terminate closely adjacent to opposite outer surfaces of the electrodeless lamp.

Abstract: An arc spinner type interrupter has a stationary coil coupled magnetically to a disk-shaped arc runner. A magnetic core encases the coil and has an annular gap extending across the upper exposed surface of the arc runner to permit access of an arc root to the arc runner. The magnetic core material has high permeability at currents lower than the rated interrupting current of the device and the magnetic material saturates at higher current levels. The effect of the relatively high permeability saturable magnetic core is to increase the transient recovery voltage recovery characteristics of the interrupter at low currents without having to increase the number of turns of the coil. The electrical coil may be made of a spirally wound, relatively thin sheet of highly conductive material, or can be made of a square conductor wound in a coil form. The axial length of the coil is increased beyond that of prior art coils without substantially increasing the reluctance of the magnetic circuit.

Abstract: Light source wherein high frequency power is capacitively coupled to a low pressure discharge includes at least one metallized power coupling conductor. A discharge lamp includes an envelope which is typically pear-shaped with a re-entrant cavity. The lamp envelope encloses a fill material which forms during discharge a plasma which emits ultravoilet radiation and typically includes on its inner surface a phosphor coating. An outer conductor is disposed around the outer surface of the lamp envelope. A conductive coating disposed on the inner surface of the re-entrant cavity forms the inner conductor. The outer conductor can be a conductive mesh or can be a conductive coating disposed on the outer surface of the lamp envelope in a pattern which permits light to escape from the lamp.

Abstract: An arc runner structure is described for an arc spinner type of interrupter wherein the arc runner is in series with an electrical coil which is closely coupled to the arc runner. The coil current and a circulating current induced in the arc runner produce a magnetic field in an arcing space where the magnetic field interacts with the arc current to produce a Lorentz force which rotates the arc around the arc runner and relative to a cool static dielectric gas, in order to extinguish the arc. A high Lorentz force is desired since this produces a higher arc spinning speed and thus improved interruption operation. The magnetic field strength produced, and its relative phase shift with respect to the arc current, is controlled by the inductance of the arc runner, its mutual coupling to the coil and the resistance of the arc runner. These parameters determine the induced current in the arc runner for a given configuration.

Abstract: A circuit interrupter is described in which the arc current to be interrupted is rotated in a relatively static sulfur hexafluoride gas. The arc is rotated by a Lorentz force produced by the interaction of a magnetic field which has at least one component extending perpendicularly to the arc and the arc current. The magnetic field is the resultant field produced by the field of a coil which is in series with the arc current and the field of a circulating current which is induced in an arc runner disposed perpendicularly to the current path. The arc runner acts as a stationary arcing contact and has a general washer type shape, and the arc root circulates around one surface of the arc runner.

Abstract: A basic fused refractory material consisting essentially of, by weight on the oxide basis, 50-67% MgO, 33-50% CaO, and preferably at least 98% MgO + CaO. The method of producing the fused refractory material by melting and solidifying a batch of refractory raw materials, wherein the cooling rate inducing solidification throughout the fused melt is at least 600 Centigrade degrees per hour and sufficient to yield the fused refractory product characterized by a fine microstructure retaining at least 2.0% MgO in solid solution in the lime phase and increased hydration resistance of the fused refractory material.

Abstract: A refractory of fused or dead-burned dolomitic grain bonded with fine magnesite. The dolomitic grain is divided into three coarse and intermediate particle size fractions in the batch, while the magnesite is alone in the fine fraction. The four particle fractions are separated by three discrete gaps in the size distribution of particles resulting in a burned refractory of high hot strength and corrosion resistance to furnace slags in basic oxygen furnaces. The width of each gap is at least equivalent to the gap created by removing, from a ground raw material batch with continuous particle size distribution, the raw material retained on one primary Tyler sieve after screening (sizing) the batch.

Abstract: A refractory of fused or dead-burned dolomitic grain bonded with fine magnesite. The dolomitic grain is divided into one coarse and one intermediate particle size fraction in the batch, while the magnesite is alone in the fine fraction. The fine, intermediate and coarse fractions are separated by large discrete gaps in the size distribution of particles resulting in a burned refractory of high hot strength and corrosion resistance to slags in basic oxygen furnaces. The width of each large gap in the particle size distribution is at least equivalent to the gap created by removing from a ground raw material batch, with a continuous particle size distribution, the particles retained on at least three consecutive primary Tyler sieves after screening (sizing) the batch.

Abstract: Basic refractory batch of coarse and intermediate sized fused or dead-burned dolomitic grain with 20-35% of a fine fraction of dead-burned magnesia and an effective amount of a compound yielding not more than 4% by weight (preferably 0.5-2.5%) zirconia, silica, or mixtures thereof. The dolomitic grain is separated into 2 size fractions (both collectively in the range of -4+65 Tyler mesh) while the magnesite is all -100 Tyler mesh and preferably at least 75% -325 Tyler mesh. The zirconia and silica yielding materials are preferably substantially all -325 Tyler mesh. Formed shape made from the batch and burned at 1600.degree.C is characterized by a modulus of rupture at 1340.degree.C (hot strength) consistently above 1800 psi and occasionally approaching 3000 psi without a significant loss in corrosion resistance to molten basic oxygen furnace slags.