Metaloxide varistors ovs surface mount varistors sm7 series ohs description the littelfuse sm7 is a plasticencapsulated surface mount mov in a pps material molded package with tinplated terminal which is fully qualified in lead free. Varistors vary quite heavily between different models. Metal oxide varistor article about metal oxide varistor. Pdf reliability evaluation of metal oxide varistors for. Metaloxide varistors ovs surface mount varistors sm7 series. The series of a varistor varies depending on the voltage it can hold, the devices it is used to control, and the type of power used in its build. Specifications are subject to change without notice. The power so developed must be within the speci cations shown on the device ratings and speci cations table for the speci c. Metaloxide varistors movs radial lead varistors tmov and. Metal oxide varistormov failure all about circuits. The most famous type of varistor is metal oxide varistor mov, which is also called as zno varistor. Users should verify actual device performance in their specific applications.
Vdr metal oxide varistors standard additional resources ordering information the varistors are available in a number of packaging options. Varistor symbol and applications metal oxide varistor. Metal oxide varistor tvr type pdf free download docplayer. It provides very good voltage transient protection and is. Pdf metal oxide varistors movs are the essence of surge protection devices. Metaloxide varistors ovs surface mount varistors sm7 series ohs description the littelfuse sm7 is a plasticencapsulated surface mount mov in a pps material molded package with tinplated terminal which is fully qualified in lead free soldering and available for both re. The mov20dxxxk series of 20 mm radial leaded varistor devices protects against overvoltage transients such as lightning, power contact and power induction. Metal oxide varistor tvrd series disc type varistor for surge protection high surge series thinking electronic industrial co. Metal oxide varistor mov technology is the most prevalent technology utilized in electrical transient protection products today. Metaloxide varistors movs radial lead varistors ultramovtm 25s varistor series rohs description features lead free and rohs compliant. Metal oxide varistors definition of varistor terms rated rms voltage, rated dc voltage the maximum designated values of power system voltage that may be applied continuously between the terminals of a device varistor voltage test characteristic that is used to classify varistors by type. Cnr14d221k varistors datasheet pdf oxide varistors. Metaloxide varistors movs radial lead varistors tmov. Metal oxide varistors consist of approximately 90% zinc oxide as a ceramic base material plus other filler materials for the formation of junctions.
The series of a varistor varies depending on the voltage it can. Pdf comparative study of metal oxide varistors movs for. Metaloxide varistors ovs surface mount varistors sm7. The metal oxide varistor is designed to protect various types of electronic devices and semiconductor elements from switching and induced lightning surges. This is achieved through a special dielectric material formulation which also results in higher repetitive surge ratings than other mov types. Bulk on tape and reel on tape in ammopack fanfold the basic ordering code for each option is given in tables titled varistors on tape on reel, varistors on tape in ammopack and varistors in bulk. Items are lead free and antimony free, available as r packing option only.
Metal oxide varistors definition of varistor terms rated rms voltage, rated dc voltage the maximum designated values of power system voltage that may be applied continuously between the terminals of. Metal oxide znobased varistor ceramics 331 conductors. The maximum energy within the varistor voltage change of 10% when one impulse of 10. The tinned copper alloy terminals are suitable for snpb and leadfree wave and reflow solder. The operation of metal oxide varistor and silicon carbide varistor are very similar. Metal oxide varistor definition of metal oxide varistor. If lightning strikes a nearby power line, the high voltage causes the mov to become a shunt, preventing the. Metal oxide varistor mov data sheet features wide operating voltage v 1ma. Metaloxide varistors movs industrial high energy terminal varistors dhb34 series dimensions mm dia 3. Both bi 2o 3rich and zn 7sb 2o 12 spinel phases are also usually present at the grain boundaries of the zno, but the presence of a bi 3zn. Metal oxide varistor 7mm disc, jvr07nk65p pdf download rfe international. They are a type of nonlinear device that feature similar characteristics to zener diodes. Typical applications include motor control, telecom, solenoid, and power supply circuits to protect. The ciii varistor series of metal oxide varistors movs are specifically designed for applications requiring high surge energy absorption ratings and superior multiple pulse absorption rating.
The specified voltage shall be applied between both terminals of the specimen connected together and the electrode inserted between the metal balls. The varistors consist of a disc of low zno ceramic material with two solid copper leads s20 types only or copper clad steel wire. Sep 22, 2015 the operation of metal oxide varistor and silicon carbide varistor are very similar. The power so developed must be within the specifications shown on the. How a surge protector works metal oxide varistor youtube. Another symmetrical device, the metal oxide varistor, is made of a ceramiclike material comprising zinc oxide grains and a complex amorphous intergranular material. During the sintering process the metal oxide powder transforms to a dense ceramic body with varistor properties. They are used to protect vulnerable electronic circuits and components from overvoltage conditions that can cause damage. Metaloxide varistors movs radial lead varistors za series description the za series of transient voltage surge suppressors are radial leaded varistors movs designed for use in the protection of low. Metaloxide varistors movs radial lead varistors ultramov tm 25s varistor series 100 0 0. Here the body is made of a metal oxide, mostly zinc oxide grains.
Bourns mov product portfolio offers 7, 10, 14, and 20 mm radial leaded varistor devices which protect against overvoltage transients such as lightning, power contact and power induction. For example, a metal oxide varistor has a different build than a series built out of crystals. Metaloxide varistors movs radial lead varistors za series. Since sic varistors had some serious drawbacks, another type of varistors the metal oxide varistors were developed. General information the mov20dxxxk series of 20 mm radial leaded varistor devices protects against overvoltage transients such as lightning, power contact and power induction. This type contains a ceramic mass of zinc oxide grains, in a matrix of other metal oxides, such as small amounts of bismuth, cobalt, manganese oxides, sandwiched between two metal plates, which constitute the electrodes of the device. Metal oxide varistor mov data sheet pulse electronics.
The varistors are available in a number of packaging. It has a high resistance about 10 9 ohms at low voltage due to the high resistance of the intergranular phase, which becomes nonlinearly conducting in its control range 100. The surfaces of the intercrystalline fracture follow. Vdrh series vdr metal oxide varistors high surge vishay. C ambient temperature, the peak surge current and energy ratings must be reduced as shown below. One of the movs connected between earthgnd and line fails frequently. Normally, the mov has very high electrical resistance. How a common surge strip works explained by ge global research engineer bill morris. Metaloxide varistors movs industrial high energy terminal.
Many industry manufacturers, including current technology, integrate various sizes of radial or straptype movs into their products. Metal oxide varistors rga varistor varistors are voltage dependent. The gemov surge suppressor was developed first in 1973 by john d. Sintering zinc oxide together with other metal oxide additives under specific conditions produces a polycrystalline ceramic whose resistance exhibits a pronounced dependence on voltage. For higher frequencies, such as radio communication equipment, a gas discharge tube gdt may be utilized. Lead free wave soldering recommendation 300 4 250 200 150 100 50 0 t e m p e r a t u r e. High peak surge current rating i tm 22ka, single 820s pulse, 25mm standard operating voltage range compatible with common ac line voltages 115 to 750vac custom voltage types available. A metal oxide varistor mov is an electronic device that protects an appliances power supply from voltage spikes and surges in the ac power line. They are cheap to manufacture, which means they are often used in inexpensive surge protectors. Metal oxide varistor article about metal oxide varistor by. Specialty movs metal oxide varistors are available in unique form fits and possess various voltage range and surge capabilities. The downside is that if they stop a power surge, they can effectively burn out, but the user may have no idea this has happened.
A metal oxide varistor starts conducting current at rated voltage and it stops the conduction if the applied. Metal balls method, 2500 vrms, 60 s the varistor is placed in a container holding 1. Halogen free and rohs compliant 3pf, 12pf, and 22pf capacitance versions. It is called so as the component is made from a mixture of zinc oxide and other metal oxides like cobalt, manganese and. A metal oxide varistor starts conducting current at rated voltage and it stops the conduction if the applied voltage is below the threshold value. Metal oxide varistors movs radial lead varistors za series description the za series of transient voltage surge suppressors are radial leaded varistors movs designed for use in the protection of low and mediumvoltage circuits and systems. Metal oxide varistor synonyms, metal oxide varistor pronunciation, metal oxide varistor translation, english dictionary definition of metal oxide varistor. The devices have a high current handling, high energy absorption capability and fast response times to protect against transient faults up to rated limits. A test current of 1 ma dc is typically used to determine. Metaloxide varistors movs radial lead varistors ciii varistor series ciii series speci cations continued from previous page notes. A resistor is a circuit that does not conduct electricity well. It provides very good voltage transient protection and is now quite popular.
The main difference between a silicon carbide varistor and a metal oxide varistor is the amount of leakage current. Mov14dxxxk series metal oxide varistor rohs directive 200295ec jan. Metaloxide varistors movs radial lead varistors tmov and itmov varistor series rohs description features rohs compliant halogen free and lead free available designed to facilitate compliance to ul1449 for spd products high peak surge current rating up to 10ka wave solderable standard lead form and spacing option. It is called so as the component is made from a mixture of zinc oxide and other metal oxides like cobalt, manganese and so on and is kept intact between two electrodes which are basically metal plates. The most common modern type of varistor is the metal oxide varistor mov. Withstanding surge current the maximum current within the varistor voltage change of. Dear all, i am using an mov for surge protection in one of our application. Integrated varistors consist of a 40ka varistor building block mov with an integral thermally activated element. Another symmetrical device, the metaloxide varistor, is made of a ceramiclike material comprising zinc oxide grains and a complex amorphous intergranular material. Many industry manufacturers, including current technology, integrate. Apr 18, 2020 the metal oxide varistor is not a perfect solution to power surges.
Metal oxide varistors, more commonly known as movs are devices that provide excellent transient voltage suppression. Withstanding surge current the maximum current within the varistor voltage change of 10% with the standard impulse current 820. A metal oxide varistor is a device used as a component in electrical equipment. Figure 3 shows the conduction mechanism in a varistor element in simplified form. They are a type of nonlinear device that feature similar characteristics to zener. The metal oxide varistors offer a choice of varistor voltages from 18 v to 1800 v and v rms voltages from 11 v to 1100 v. Average power dissipation of transients not to exceed 0. California 91605 phone 818 7658300 toll free 800 8277422 fax 818 765. The metal oxide varistor is designed to protect various types of. Metal oxide varistor mov, basics, working, specifications. The metal oxide varistors offer a choice of varistor voltages from 18 v to 1800 v and vrms voltages from 11 v to 1100 v. Jvr05nk metal oxide varistor components datasheet pdf data sheet free from datasheet data sheet search for integrated. The metal oxide varistor or mov for short, is a voltage dependant resistor in which the resistance material is a metallic oxide, primarily zinc oxide zno pressed into a ceramic like material. Jvr10nk datasheet, jvr10nk pdf, jvr10nk pinout, jvr10nk equivalent, jvr10nk replacement metal oxide varistor rfe, schematic, circuit.
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