Insulator (electricity)

About: Insulator (electricity) is a research topic. Over the lifetime, 15941 publications have been published within this topic receiving 108950 citations. The topic is also known as: electrical insulator.

Enhanced partial discharges due to temperature increase in the combined system of a solid-liquid dielectric

Abstract: Partial discharges which emanate from solid dielectrics immersed in insulating oil when high impulse voltages are applied under different environmental temperatures (20, 40 and 80 degrees C) are discussed. The solid dielectrics used for the measurements are phenol-impregnated pressboard and industrial bakelite. The samples are cut in wafers of 150 mm diameter and are 1 or 2 mm thick. The insulating oil is a typical transformer oil. The switching type of the impulse voltage used, 250/2500 mu s, corresponds to functional situations and is long enough to produce the effects that can be detected without the consideration of charge transfer phenomena due to fast rates of field changes. Experimental results show that the total charge transfer due to partial discharge is increased by temperature. A possible explanation of the undergoing physical process may be that in the low-field regime, temperature perturbation effects on the injected current are characterized by the conductivity changes in the volume of the dielectric, while as partial discharges start occurring, avalanche multiplication of conduction electrons appears to be the dominant phenomenon, characterizing the behavior of a metal/thick insulator/metal structure in the high-field regime. The circuits, measurement, and measuring procedures are discussed. >

Improvement of Characteristics of Organic Thin-Film Transistor with Anodized Gate Insulator by an Electrolyte Solution and Low-Voltage Driving of Liquid Crystal by Organic Thin-Film Transistors

Abstract: The characteristics of pentacene-based organic thin-film transistors (OTFTs) on plastic substrates with anodized gate insulators using different electrolyte solutions were investigated. The characteristics were significantly improved by using ammonium borate as the solution. The results show a good current-saturation characteristic, field-effect mobility of 0.51 cm2/Vs and a current on/off ratio of 105 at a low drain voltage of 3 V. To investigate the reason for the improvements, the structural and electrical characteristics of OTFTs and insulators were examined using various methods such as X-ray diffraction, atomic force microscope, capacitance-voltage measurement and secondary ion mass spectroscopy. From the results of these experiments, it was found that the orientation of pentacene was improved and the concentration of impurities in the insulator decreased in the case of ammonium borate. We also examined low-voltage driving of liquid crystal devices by the OTFT, targeting its application for flexible displays. Improvement of characteristics by the solution was also confirmed in the driving.

Superconductor/insulator metal oxide hetero structure for electric field tunable microwave device

Abstract: A superconductor/insulator metal oxide hetero structure for electric field tunable microwave device, including a dielectric substrate, a first superconducting electrode of an oxide superconductor provided on said dielectric substrate, an insulating layer formed on the first superconducting electrode and a second electrode arranged on the insulating layer in which the conductivity of the first superconducting electrode and/or the dielectric property of the insulating layer can be changed by a dc bias voltage applied between the first and the second electrodes so that surface resistance and/or surface reactance can be changed.

High-uniformity multichannel plasmonic filter using linearly lengthened insulators in metal-insulator-metal waveguide.

Abstract: A high-uniformity multichannel plasmonic filter based on metal–insulator–metal (MIM) waveguide is proposed. It consists of two metal layers and sandwiched multiple insulator super units structured by alternately stacking two insulators with different refractive indices. By linearly lengthening the high refractive index insulators in each super unit, the dispersion-induced loss coefficient can be reduced and flattened, leading to a high uniformity among multiple transmission channels of the plasmonic filter. The corresponding spectral characteristics are numerically investigated by using the finite-difference time-domain method. Fourteen transmission channels with an excellent channel uniformity of ±0.2 dB and a peak-to-notch contrast ratio greater than 14.8 dB in the range of 1–2 μm, have been confirmed.

RTV silicone rubber pre-coated ceramic insulators for transmission lines

Abstract: The paper gives the state-of-the-art on pre-coated ceramic insulators for transmission lines. The usage of pre-coated ceramic insulators has mainly been in coastal areas where sea salt causes flashovers of ceramic insulators. The experience to date has been very good everywhere with very few problems reported. Interest in the pre-coated insulator concept continues to be strong everywhere. The paper also provides guidelines to assist the user in the specification of pre-coated ceramic insulators.