Suntan Metal Oxide Varistor
A metal oxide varistor, or MOV, is a voltage dependent, nonlinear device that provides excellent transient voltage suppression. When exposed to high transient voltage, the metal oxide varistor clamps voltage to a safe level. A metal oxide varistor absorbs potentially destructive energy and dissipates it as heat, thus protecting vulnerable circuit components and preventing system damage.
Varistors are non-linear, voltage-dependent resistors whose value of resistance decreases with increasing voltage. Varistors are mainly used for over-voltage protection. Varistors are utilized in low-voltage electronic equipment for absorbing high-voltage pulsative noise while bypass capacitors are utilized for removing low-voltage and high-frequency alternating noise.
An advanced device having both the functions is a ceramic capacitor with varistor performance. Varistors are commonly made by sintering particulate metal oxides, with or without minor amounts of other inorganic materials, as in disk or rod form. Metal oxide varistors (MOV) are semiconductor devices that are fabricated using technology from the ceramic capacitor industry. Zinc oxide varistors are ceramic semiconductor devices based on zinc oxide. Varistors are produced by a ceramic sintering process which gives rise to a structure consisting of conductive zinc oxide grains surrounded by electrically insulating barriers. These barriers are attributed to trap states at grain boundaries induced by additive elements such as bismuth, cobalt, praseodymium, manganese and so forth. A monolithic chip varistor is generally provided with a varistor body including a plurality of varistor layers composed of a zinc oxide-based ceramic material and at least one pair of internal electrodes opposed to each other with one of the varistor layers there between , and a pair of external electrodes.
Suntan metal oxide varistor devices are made primarily of zinc oxide with small amounts of bismuth, cobalt, manganese, and other metal oxides. They can be connected in parallel for increased energy-handling capabilities. MOVs can also be connected in series to provide higher voltage ratings or to provide voltage rating between the standard increments.
