(1) distinguish between power supply protection, or signal lines, data lines with TGE Varistor for counter protection, they are to meet different technical standards.
(2) Depending on the varistor applied continuous operating voltage can be across the line with a varistor can be divided into AC or DC with the use of two types, varistors in both voltage stress different aging characteristics performance.
(3) According to the varistor withstand abnormal over-voltage characteristics of different, can be divided into varistor for surge suppression, high-power and high-energy type of these three types.
Surge suppression: is used to suppress lightning over-voltage and over-voltage and other transient over-voltage varistor, this transient overvoltage occurs it is random, and current-voltage non-peak periods may be Big. The vast majority mov metal oxide varistor fall into this category.
High power type: refers to the absorption cycle for continuous bursts appear varistor, for example, and connected to the switching power converter varistor voltage cycle where impact occurs, and the cycle shows that the energy value may be calculated in general out, the peak voltage is not large, but the high frequency of occurrence, the average power is considerably large.
Energy Type: generator means for absorbing the excitation coil, and other large lifting electromagnet coil inductance coil magnetic energy varistor voltage is, for such applications, the main technical indicators are energy absorption capability.
Varistor protection, the vast majority of applications, it can repeatedly effect, but sometimes also to make it into the current fuse as a "one-off" protection device. For example, and then on some of the short-circuit current transformer load contacts TGE metal oxide varistor identification.
MOV
2015年8月20日星期四
2015年8月18日星期二
High voltage gradient zinc oxide varistor formulation and preparation methods
Reasonable formula of TGE metal oxide varistor sizing is preferably the component with the content of the zinc oxide varistor, prepared using the formulation of zinc oxide varistor with up to 350 ~ 600V / mm high voltage gradient, while at the high voltage gradient, oxidation zinc varistor capable of maintaining good nonlinear properties, electrical properties and anti-aging properties, in order to meet the practical application of electronic components, such as arrester miniaturization requirements. The preparation method of zinc oxide varistor resistance of the zinc oxide film sub-component and trace ingredients and mix evenly matched tiny size, reduce the amount of contamination, while the addition of the low-temperature thermal processes during the sintering process leaving the metal oxide varistor basics to form a stable grain boundary structure, help to improve the stability of the zinc oxide varistor and a secondary heat treatment during the phase transition of bismuth oxide, thereby improving the electrical properties of TGE Glass Coating varistors.
Zinc oxide can be inserted to corrosion or food supplement zinc, but the product demanding, especially to control the content of harmful heavy metals.
Zinc oxide itself is not toxic, but can be inhaled zinc oxide particles are harmful.
Zinc smelting industry, preparation of brass, galvanized work are likely to produce zinc oxide smoke.
To prevent smoke, galvanized iron can not be welded directly, you must first remove the surface film of zinc.
Zinc oxide can be inserted to corrosion or food supplement zinc, but the product demanding, especially to control the content of harmful heavy metals.
Zinc oxide itself is not toxic, but can be inhaled zinc oxide particles are harmful.
Zinc smelting industry, preparation of brass, galvanized work are likely to produce zinc oxide smoke.
To prevent smoke, galvanized iron can not be welded directly, you must first remove the surface film of zinc.
Zinc oxide varistors major role in the electrical industry
Many TGE mov varistor for counter used in the product must use explosion-proof zinc oxide varistors, which is specified in the Design Manual: The controller does not allow the choice of non-explosion type varistor varistors, air-conditioning control panel functions as designed distinction, lightning varistor generally refers to the use of varistors between power line and the earth, sometimes leaving the voltage rise due to poor ground between line and ground, so the ratio between the line and usually use the occasion higher nominal line varistor voltage. Varistor in the circuit must be considered able to withstand the lightning over-voltage, over-voltage and over-voltage transient frequency effects. Lightning varistor and fuse or general discharge with the use of the power portion of the first stage ZNR varistor in parallel with the power transformer primary coil ends, with fuse tubes series circuit, surge voltage suppression.
Under normal circumstances, voltage, resistance zinc oxide varistors great can be achieved by Meg level (the current flowing through it only microampere level, can be ignored), in the open state, no effect on the circuit. But when you experience a power voltage exceeds the breakdown voltage, its resistance suddenly reduce design to a few tenths of Europe even in Europe, up to the current moment by thousands of amperes, ZnO varistor immediately turned on by the deadline, because it and power supplies in parallel, so soon the power fuse blows, the main circuit board to prevent burn out. In addition, when faced with a slight momentary power surge fluctuation (220 ± 10%), varistor buffer will absorb this flow Chung clutter, there are encountered lightning, transformers and other inductive circuit switching operation, instantaneous overpressure effect produced on varistor, its resistance suddenly decreases, the current through the large drainage role to play to protect the entire circuit, this effect is called over-voltage protection. Varistors ZNR common in the schematic representation.
Zinc oxide varistors can also be used as over-voltage protection. Over-voltage atmospheric over-voltage and over-voltage points. Atmospheric over-voltage caused by lightning: Operating overvoltage is due to mutations in the electrical system status, sharp electromagnetic energy caused by the conversion. TGE metal oxide varistor theory is mainly used for lightning induced over-voltage protection, over-voltage electronic devices (surge) absorption, relay contacts spark arrestor, transistors, thyristors, integrated over-voltage protection switch current.
Under normal circumstances, voltage, resistance zinc oxide varistors great can be achieved by Meg level (the current flowing through it only microampere level, can be ignored), in the open state, no effect on the circuit. But when you experience a power voltage exceeds the breakdown voltage, its resistance suddenly reduce design to a few tenths of Europe even in Europe, up to the current moment by thousands of amperes, ZnO varistor immediately turned on by the deadline, because it and power supplies in parallel, so soon the power fuse blows, the main circuit board to prevent burn out. In addition, when faced with a slight momentary power surge fluctuation (220 ± 10%), varistor buffer will absorb this flow Chung clutter, there are encountered lightning, transformers and other inductive circuit switching operation, instantaneous overpressure effect produced on varistor, its resistance suddenly decreases, the current through the large drainage role to play to protect the entire circuit, this effect is called over-voltage protection. Varistors ZNR common in the schematic representation.
Zinc oxide varistors can also be used as over-voltage protection. Over-voltage atmospheric over-voltage and over-voltage points. Atmospheric over-voltage caused by lightning: Operating overvoltage is due to mutations in the electrical system status, sharp electromagnetic energy caused by the conversion. TGE metal oxide varistor theory is mainly used for lightning induced over-voltage protection, over-voltage electronic devices (surge) absorption, relay contacts spark arrestor, transistors, thyristors, integrated over-voltage protection switch current.
Zinc oxide varistors used in automotive circuits
Automotive products of TGE metal oxide varistor symbol have become increasingly demanding, more and more attention because of the zinc oxide varistor has a good protective effect, good or bad quality can directly affect the use of the car, zinc oxide varistors and at the circuit input is broken, there is no impact on the normal circuit operation, when for some reason caused by the input voltage is increased to a certain value. varistor will burn to protect further damage to the circuit. (Varistor protection element one-off, so after the breakdown want to change with the type of new elements)
1. zinc oxide varistor structure like two characteristics consistent back-coupled regulator, which is basically the same nature. The main characteristics of the varistor, when the ends of the applied voltage is within the nominal rating, its resistance value is almost infinite, in a high impedance condition, the leakage current of <50 microamps, when the voltage across it slightly exceeded rated voltage, its resistance drops sharply immediately in the conduction status, the operating current increases several orders of magnitude, and the reaction time is only in nanoseconds. metal oxide varistor application in foreign commonly known as "chopper" and "limiter", which is from its practical effect and its name.
2. zinc oxide varistor in the circuit can absorb such counter electromotive force, thereby effectively protect the switching circuit from damage. In the car the most used appliances or car computer board in power protection circuit, TGE metal oxide varistor testing Toyota cars computer board with a sheet of black circle, while American cars and Daewoo cars in the pressure-sensitive computer board Most resistance is red, if the car alternator voltage regulator failure, resulting in long lines and battery voltage is too high or the battery pile loose, disengage and start using the power of the power to start the engine, often cause the computer board pressure sensitive resistor damaged.
1. zinc oxide varistor structure like two characteristics consistent back-coupled regulator, which is basically the same nature. The main characteristics of the varistor, when the ends of the applied voltage is within the nominal rating, its resistance value is almost infinite, in a high impedance condition, the leakage current of <50 microamps, when the voltage across it slightly exceeded rated voltage, its resistance drops sharply immediately in the conduction status, the operating current increases several orders of magnitude, and the reaction time is only in nanoseconds. metal oxide varistor application in foreign commonly known as "chopper" and "limiter", which is from its practical effect and its name.
2. zinc oxide varistor in the circuit can absorb such counter electromotive force, thereby effectively protect the switching circuit from damage. In the car the most used appliances or car computer board in power protection circuit, TGE metal oxide varistor testing Toyota cars computer board with a sheet of black circle, while American cars and Daewoo cars in the pressure-sensitive computer board Most resistance is red, if the car alternator voltage regulator failure, resulting in long lines and battery voltage is too high or the battery pile loose, disengage and start using the power of the power to start the engine, often cause the computer board pressure sensitive resistor damaged.
Zinc oxide varistor selection
Selection of TGE Glass Coating varistors before, you should first understand the following related technical parameters: Nominal voltage is at a predetermined temperature and DC flow, voltage across the varistor. Leakage current is at 25 ℃, when the application of the maximum continuous DC voltage, varistor flowing current value. Level refers mov metal oxide varistor voltage by 8/20 rating current pulses at both ends exhibit voltage peaks. Through traffic is applying a predetermined peak current pulse current (8 / 20μs) waveform when. Surge environmental parameters include a maximum inrush current Ipm (or the maximum surge voltage and surge Vpm source impedance Zo), surge pulse width Tt, the minimum time interval of two adjacent surge Tm and scheduled TGE high voltage varistor working life period, the total number of surge pulses N and the like.
Works zinc oxide varistor
TGE varistor metal oxide is a resistor made of zinc oxide in Taiwan is called the surge absorber, zinc oxide TGE metal oxide varistor application voltage because of the change in resistance has nonlinear way (positive and negative) also symmetry, and Can abnormal voltage response line, absorbed most of the surge / surge energy while suppressing the abnormal voltage to a safe range so that safety and stability to improve lines, and thus subject to many areas of favor.
2015年8月11日星期二
Zinc oxide use
Another major use of zinc oxide is used as a coating, 1834, for the first time became the watercolor, but insoluble in oil. But soon the problem will be solved by a new zinc oxide production process. In 1845, Leclair began mass production of zinc white oil paint in Paris, 1850, zinc oxide became popular throughout Europe. High purity zinc oxide, so that in the 19th century, some artists painted zinc white as a background in painting, but these paintings have appeared through the crack years later.
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