Results 141 to 150 of about 236 (182)

Investigation of various models for metal oxide varistors

Journal of Electronic Materials, 1976
A new type of voltage dependent resistors (varistors), based on zinc oxide ceramics with several other metal oxides as additives, has recently been investigated. The microstructure of these varistors consists of ZnO grains surrounded by thin insulating metal oxide barriers.
J. Bernasconi, H. P. Klein, B. Knecht, S. Strässler   +3 more
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Surface flashovers on metal-oxide varistor blocks

ICSD'98. Proceedings of the 1998 IEEE 6th International Conference on Conduction and Breakdown in Solid Dielectrics (Cat. No.98CH36132), 2002
Extensive studies have been made of surface flashovers on varistor blocks using multipulse (MP currents which simulate multiple stroke lightning ground flashes. The MP results are compared with those obtained with single-pulse (SP) currents and with high temporary overvoltages (TOV) at 50Hz. The blocks used were mostly of 5kA rating as commonly used in
Darveniza Mat, Saha Tapan K.
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Ageing of metal oxide varistors due to surges

2011 International Symposium on Lightning Protection, 2011
Surge arresters are exposed to a series of stresses that trigger changes in their nonlinear behaviors. This paper deals with the ageing of metal oxide varistors concerning the stresses associated to high current short duration surges. The ageing of the samples is evaluated by analyzing the evolution of the resistive component of the leakage current ...
Credson de Salles, Manuel L. B. Martinez, Alvaro Antonio Alencar de Queiroz   +2 more
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Multi-factor ageing of metal oxide varistors

Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP'94), 2002
Localised overheating of zinc oxide varistor elements due to the transfer of external leakage currents arising from the incidence of partial electrical discharges (PD) onto their outer surface has been shown to cause premature failure by surface breakdown.
N.M. Vong, D.M. Ryder, R. Miller, R.M. Doone   +3 more
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Second-breakdown characteristics of metal-oxide varistors

Journal of Applied Physics, 1977
Several new results on the electrical breakdown properties of ZnO-based ceramic varistors are presented. A second-breakdown phenomenon associated with thermal runaway and characterized by a negative differential conductivity was observed in dc tests. The curve of capacitance versus bias current exhibited hysteresis while the I-V characteristics became ...
J. J. Lee, J. K. O’Brien, M. S. Cooper
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Microwave Sintering Technology for the Production of Metal Oxide Varistors

MRS Proceedings, 1990
ABSTRACTA microwave sintering technology has been developed for the production of metal oxide varistors. The electrical properties (leakage current and non-linearity coefficient) of the microwave sintered devices were found to be comparable to those obtained for conventionally sintered varistors of identical composition.
G. McMahon, A. Pant, R. Sood, A. Ahmas, R.T. Holt   +4 more
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Development of metal oxide varistor element for power systems

Proceedings of IEEE International Symposium on Industrial Electronics, 2002
A highly nonlinear arrester can improve the insulation coordination of electrical substations and reduce the basic impulse level of power systems. Metal oxide varistors with zinc oxide as one of their constituents are used as advanced protective devices for power systems against transient overvoltages.
S.N. Roy, C.K. Roy, P.K. Bhattacharya, T.K. Gangopadhyay   +3 more
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Research on leakage current characteristic of metal oxide varistor

2017 1st International Conference on Electrical Materials and Power Equipment (ICEMPE), 2017
MOA (Metal Oxide Arrester) has been widely used in the world because of its excellent nonlinearity, long-lasting anti-aging properties and excellent overvoltage protection performance. The performance degradation of the MOV occurs in the long-running process because of environmental reasons, so the online monitoring system for the MOA has a great ...
Xuni Rao, Jie Guo, Yue Zhou, Qi Wei, Xing Liu   +4 more
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Metal oxide varistor-A multijunction thin-film device

Applied Physics Letters, 1974
The physical origin of the highly nonlinear current-voltage relation in metal oxide varistors is shown to be consistent with Fowler-Nordheim tunneling.
Lionel M. Levinson, H. R. Philipp
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Long-time polarization currents in metal-oxide varistors

Journal of Applied Physics, 1976
The low-frequency (100–10−4 Hz) behavior of metal-oxide varistors is obtained from analysis of the charging and discharging currents which flow upon the application and removal of a step voltage. These results are compared to data for the complex dielectric constant ε=ε′−iε″ obtained using an ac bridge in the frequency range 101–10−1 Hz.
H. R. Philipp, Lionel M. Levinson
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