Results 51 to 60 of about 88 (88)
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Microchemistry of ZnO Varistors
Proceedings, annual meeting, Electron Microscopy Society of America, 1992ZnO varistors are made by mixing semiconducting ZnO powder with powders of other metal oxides e.g. Bi2O3, Sb2O3, CoO, MnO2, NiO, Cr2O3, SiO2 etc., followed by conventional pressing and sintering. The non-linear I-V characteristics of ZnO varistors result from the unique properties that the grain boundaries acquire as a result of dopant distribution ...
K. K. Soni +4 more
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Sintering effect on varistor properties and degradation behavior of ZVMB varistor ceramics
Journal of Materials Science: Materials in Electronics, 2017ZnO–V2O5–Mn3O4–Bi2O3 (ZVMB) varistor ceramics were sintered at a low temperature range of 800–875 °C, and the microstructure, electrical properties, dielectric characteristics, and DC-accelerated aging behavior were systematically investigated. Analysis of the microstructure indicated that the average grain size increased from 3.8 to 6.4 µm with the ...
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[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials, 2002
The frequency characteristics of the capacity and the dissipation factor of a ceramic ring varistor have been measured in the range from 10 kHz to 1 MHz. From the measurements, the equivalent circuit was determined, considering the internal structure of the ceramic ring varistor.
M. Suzuki +3 more
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The frequency characteristics of the capacity and the dissipation factor of a ceramic ring varistor have been measured in the range from 10 kHz to 1 MHz. From the measurements, the equivalent circuit was determined, considering the internal structure of the ceramic ring varistor.
M. Suzuki +3 more
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Journal of Physics: Condensed Matter, 1993
Among the mechanisms suggested to account for degradation of varistor materials, ion migration has strong support. Mobile, positively charged ions in the depletion layer would be the key element in degradation. In this context, the authors discuss the consequences of an electrical stressing on the current-temperature characteristic of a comment ...
M S Castro, M A Benavente, C M Aldao
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Among the mechanisms suggested to account for degradation of varistor materials, ion migration has strong support. Mobile, positively charged ions in the depletion layer would be the key element in degradation. In this context, the authors discuss the consequences of an electrical stressing on the current-temperature characteristic of a comment ...
M S Castro, M A Benavente, C M Aldao
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Polarization currents in varistors
Journal of Applied Physics, 1990The time, voltage, and temperature dependencies of transient polarization currents are reported for two types of varistors (i.e., ZnO and a SiC composite). The current transients exhibit a power-law time response to a step change in voltage (i.e., I≊I0/tm, where m is slightly less than unity) that persists over a time scale exceeding 10−8–104 s.
F. A. Modine +4 more
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MRS Proceedings, 1981
The theory of ZnO varistors has evolved along with the increasingly detailed experimental description [1-2]. The extreme nonlinearity in the currentvoltage curves naturally led the early investigators to suggest the well-known nonlinear mechanisms, such as space-charge limited currents or electron tunneling. Later experiments made these first proposals
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The theory of ZnO varistors has evolved along with the increasingly detailed experimental description [1-2]. The extreme nonlinearity in the currentvoltage curves naturally led the early investigators to suggest the well-known nonlinear mechanisms, such as space-charge limited currents or electron tunneling. Later experiments made these first proposals
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Time Dependence of Degradation in ZnO Varistors
physica status solidi (a), 1982Starting from the results of a previous paper on the functional relationship of the degradation of ZnO-varistors and the influence factors (especially U, I,T) an equation system is derived to describe the time-dependence of the degradation. The solutions including the contribution of degradation-, recovery- and increasing effects of currents and ...
W. Brückner +2 more
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IEEE Electrical Insulation Magazine, 1989
An overview is given of zinc oxide varistors, which are made of semiconducting ceramics with highly nonohmic current-voltage characteristics, which originate at the grain boundaries. These varistors are widely utilized to protect electric power lines and electronic components against dangerous voltage surges.
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An overview is given of zinc oxide varistors, which are made of semiconducting ceramics with highly nonohmic current-voltage characteristics, which originate at the grain boundaries. These varistors are widely utilized to protect electric power lines and electronic components against dangerous voltage surges.
openaire +1 more source