Abstract: An electronic frequency inverter circuit receives input electrical power at a lower frequency and energizes a load circuit including gaseous discharge lamps in a range of higher frequencies. First and second semiconductors are operated alternatively by a logic circuit in current mode control such that the switches operate at the high frequency range and the frequency of current in the load circuit varies as the magnitude of said source voltage varies. The load circuit has an impedance which varies with frequency such that the peak amplitude of the load current remains substantially constant despite variations in the magnitude of said source voltage to achieve a desirable crest factor for the lamp current. A high current limit circuit rapidly turns off the switches when excessively high current begins to flow through the switches. Low voltage is supplied in port from the high frequency current. Normal operation is ensured during start-up, for reduced line voltage and for a semiconductor chip embodiment.

Abstract: A method of making a ZnO powder composition, which can exhibit non-linear V-I characteristics, comprises the steps of: (1) mixing about 75 mole % to about 98 mole % of small, finely divided, solid ZnO and about 2 mole % to about 25 mole % of at least one small, finely divided, solid additive oxide effective to produce nonlinear characteristics, with an aqueous binder solution comprising an organic, water soluble fugitive binder, to provide a slurry; (2) simultaneously drying, mixing and agglomerating the slurried solids into a mass of larger substantially spherical particles containing the finely divided solids and binder; (3) pressing a mass of the agglomerated particles, to provide a cohesive pressed green body; and then (4) heating the pressed body, first at a temperature rate increase effective to slowly decompose and remove the fugitive binder from the body and then heating at a temperature of between 1,050.degree. C. to about 1,400.degree. C.

Abstract: An insulated electrical member is made, having in combination, an electrical member covered with insulation and a conducting varnish, where an abrasion resistant stress grading system covers at least part of the conducting varnish, the stress grading comprising: (1) a first base layer of resinous paint containing non-linear SiC having a resistivity value of between 2,000 to 4,000 Meg. Ohm/Square, in contact with the conducting varnish, (2) a second overlapping layer of resinous paint containing non-linear SiC having a resistivity value of between 4,000 to 6,000 Meg. Ohm/Square and containing at least one fibrous support, covering the first base layer and (3) an overcoat of an arc and track resistant resinous insulating varnish; where, at the point of overlap of the SiC layers, the thickness ratio of the base SiC layer:overlapping SiC layer is from 1:1 to 1:15.

Abstract: A method is provided for detecting the presence of arcing faults in the stator windings of large dynamoelectric machines, such as turbine generators. Arcing faults, such as broken strands in a winding conductor with continued arcing, give rise to high frequency currents which flow in the neutral lead of the generator winding. The presence of the arcing fault can thus be detected by observing the high frequency neutral currents and monitoring them for the presence of the characteristic frequency distribution resulting from the resonance characteristics of the current path.