Results 171 to 180 of about 457 (219)

The physics of metal oxide varistors

Journal of Applied Physics, 1975
This paper outlines our present understanding of the conduction mechanisms and physical processes relevant to the performance of ZnO−based ceramic varistors. Varistor behavior is determined by the gross ceramic microstructure of the device as well as by the localized conduction processes which occur between grains. We show that the qualitative features
Lionel M. Levinson, H. R. Philipp
openaire   +1 more source

ac properties of metal-oxide varistors

Journal of Applied Physics, 1976
Measurements of the small-signal ac response of ZnO-based ceramic varistors are reported for frequencies f in the range 30<f<108 Hz and temperatures T in the range −200<T<300 °C. The high effective varistor dielectric constant results from the device microstructure with no detectable electrode contribution.
Lionel M. Levinson, H. R. Philipp
openaire   +1 more source

Thermal Runaway in Metal Oxide Varistors

MRS Proceedings, 1981
ABSTRACTThe conditions leading to thermal runaway in metal oxide varistors are discussed in terms of its power dissipation. An equivalent circuit is used to rationalize the similarities and differences between the DC and 60 Hz ac behavior.
Martin A. Seitz, Richard W. Hirthe, Mike E. Potter   +2 more
openaire   +1 more source

Nano-enabled metal oxide varistors

IEEE Transactions on Dielectrics and Electrical Insulation, 2009
Zinc oxide based metal oxide varistors (MOV) are widely used electrical surge protection components. The design of modern high power, high-density electronic systems necessitate the need for smaller footprint, higher current density and higher nonlinearity MOVs.
Daniel Tan, Karim Younsi, Yingneng Zhou, Patricia Irwin, Yang Cao   +4 more
openaire   +1 more source

Pressure effects on metal oxide varistors

Applied Physics Letters, 1976
Preliminary results on the strong dependence of current-voltage characteristics of ZnO-based metal oxide varistors on pressure up to ∼5 kbar (nominal) are reported. This letter perhaps constitutes the first pressure study on electronic ceramics.
J. Wong, F. P. Bundy
openaire   +1 more source

Surge ageing of metal oxide varistors

2015 IEEE Electrical Insulation Conference (EIC), 2015
The objective of this paper is to analyze the ageing of metal oxide varistors (MOV) due to surges by the changes of the nonlinear behavior. The surge arrester installed in the field is submitted to the lightning stress superposed to the power frequency voltage, and so, submitted to an ageing process due to both cumulative stresses.
Credson de Salles, Manuel L. B. Martinez, Álvaro A. A. de Queiroz   +2 more
openaire   +1 more source

Electrothermal and Overload Performance of Metal-Oxide Varistors

IEEE Transactions on Power Delivery, 2020
The energy absorption capability of metal-oxide varistors, decidedly influenced by the electrothermal processes occurring within their microstructures, is a vital parameter for the effective surge protection. This paper proposes a numerical model for the simulation of the electrothermal phenomena occurring in metal-oxide varistors.
Zumret Topcagic, Miha Mlakar, Thomas E. Tsovilis   +2 more
openaire   +1 more source

Tunneling of photoexcited carriers in metal oxide varistors

Journal of Applied Physics, 1975
ZnO-based ceramic varistors exhibit photocurrents which vary in a highly nonlinear manner with applied voltage. It follows that varistor behavior is controlled by electrical barriers at the ZnO-grain–intergranular-layer interface.
H. R. Philipp, Lionel M. Levinson
openaire   +1 more source

Frequency limitation of metal-oxide varistors

International Journal of Electronics, 1992
The frequency possibilities of metal-oxide varistors are investigated. An expression is deduced for the limiting frequency f o of their application. It is also expressed in terms of the catalogue data of commercial varistors or by means of the parameters or the ceramic material. An evaluation of the f o of ZnO, SnO2 and SrTiO3 varistors is made.
openaire   +1 more source

Capacitance changes in degraded metal oxide varistors

Proceedings of the 2004 IEEE International Conference on Solid Dielectrics, 2004. ICSD 2004., 2004
ZnO based ceramics show a highly nonlinear current-voltage (I-V) characteristic due to intergranular layers at the boundaries of ZnO grains. This research indicates that the junctions formed on the border between ZnO grains and the intergranular phase are responsible for the creation of potential barriers which control the flow of current through the ...
M. Jaroszewski, K. Wieczorek, W. Bretuj, P. Kostyla   +3 more
openaire   +1 more source