Varistor ZnO and lighting technology

Varistor ZnO is an electronic ceramic with many electric and electronic applications. It is typically featured by line curvilinear - great terminal pressure. Therefore, it easily turns from an insulating into a conducting state when overpressure phenomenon occurs. Hence, Varistor ZnO is being increasingly applied into electronic and electric circuits as the best choice in overpressure prevention now.

During previous research and development, 5 varistor generations have been discovered and documented. Since 2001 scientists have been using a sol-gel technique to create varistors with semi-conductive membrane of nano dimension. Thus, electrical properties of varistors have been greatly improved. With these varistors, the industry could manufacture lightning arresters to protect all electric and electronic circuits with pressure ranging from small Vol to hundreds of Kilowon, voltage from limited microamperes to hundreds of thousands of kiloampers. These are the 5th generation varistors.

Now these 5th generation varistors are regarded as a state of threat achievement in lightning arresters and results obtained from the trial project: “Apply and implement production technology for varistor ZnO of new generation for high tech lighting equipments” headed by Doctor Nguyen The Hung in 2005-2006.

5th generation varistors

5th generation varistors are used to assemble lightning arresters for low voltage. They are used to protect telecommunication, computer networks, electric tools in households,…

Lightning arresters for low voltage using 5th generation varistors

5th generation varistors are assembled with lightning arresters for high voltage (up 35kV pressure) covered by silicon. This is a significant variation as previous lightning types are all covered by ceramics. Silicon covers make lightning arresters light persistent to severe tropical climate in Vietnam, territorial waters, regions with high corrosion and unbroken when surface discharge occurs. Additionally, their price is affordable. These lightning arresters for low voltage can replace imported equipments of the same type.

lightning arresters for high voltage covered by silicon for 35kV pressure

Based on research data and implementation, researcher groups have transferred technology to some domestic and international agencies such as Soulé in Bigno de Bagnes (France), KVA (Brasil), Basam Toos (Iran) and Ha Noi Material and Technology Company.
 

Translated by Hoang Lien
Link to Vietnamese version