UF Capacitors produce varistors as protection components, the varistors have three level, standard type, high energy type, and power meter level. Power meters need to use lots of varistors.
What is a varistor?
Varistor is a type of resistance device with nonlinear volt ampere characteristics, mainly used for voltage clamping when a circuit is subjected to overvoltage, absorbing excess current to protect sensitive devices. Its English name is" Voltage Dependent Resistor ", abbreviated as" VDR "or" Varistor ". The material of the resistor body of varistors is semiconductor, so it is a variety of semiconductor resistors. Nowadays, zinc oxide (ZnO) is widely used Varistor, its main material consists of divalent element zinc (Zn) and hexavalent element oxygen (O). So from a material perspective, zinc oxide varistors are a type of "II VI group oxide semiconductor".
Varistor is a voltage limiting protective device. By utilizing the nonlinear characteristics of varistors, when overvoltage occurs between the two poles of the varistor, the varistor can clamp the voltage to a relatively fixed voltage value, thereby achieving protection for the subsequent circuit. The main parameters of a varistor include: varistor voltage, current capacity, junction capacitance, response time, etc.
The response time of the varistor is ns level, which is faster than the gas discharge tube and slightly slower than the TVS tube. Generally, its response speed can meet the requirements for overvoltage protection in electronic circuits. The junction capacitance of varistors generally ranges in the order of several hundred to several thousand Pf. In many cases, it is not suitable to directly apply it to the protection of high-frequency signal lines. When applying it to the protection of AC circuits, because its junction capacitance can increase leakage current, it needs to be fully considered when designing protective circuits. The flow capacity of a varistor is larger, but smaller than that of a gas discharge tube. Varistor, abbreviated as VDR, is a nonlinear overvoltage protection semiconductor component that is sensitive to voltage.
The working principle of varistors
When the voltage applied to the varistor is below its threshold, the current flowing through it is extremely small, equivalent to a resistor with an infinite resistance value. That is to say, when the voltage applied to it falls below its threshold, it acts as an open switch.
When the voltage applied to the varistor exceeds its threshold, the current flowing through it surges, which is equivalent to an infinitesimal resistance. That is to say, when the voltage applied to it exceeds its threshold, it acts as a closed state switch.
Advantages of varistors
Various diameter sizes: 5mm, 7mm, 10mm, 14mm, 20mm
Wide range of variable resistance voltage: 18V-1800V
Multiple surge withstand capabilities: standard, high surge, ultra high surge
High current processing and energy absorption capacity
The flow rate of a single unit can reach 70KA or even higher
Fast reaction time
Low leakage current
Multiple lead forms: straight, curved, and other special lead types
Multiple packaging forms: Bulk, Ammo packaging, Reel packaging
The Function and Precautions of Varistors
Varistors are mainly used for transient overvoltage protection, but their volt ampere characteristics similar to semiconductor voltage regulators also enable them to have various circuit component functions, such as being used as:
(1) DC high-voltage and small current voltage stabilizing components can have a stable voltage of over thousands of volts, which cannot be achieved by silicon voltage regulators.
(2) Voltage fluctuation detection element.
(3) DC level shifting element.
(4) Equalizing element.
(5) Fluorescent starting element
In addition, attention must also be paid to:
UF Capacitors is your reliable Partner in China, our factory is specialized in manufacturing of Radial Leaded Varistors. After 26 years development, UF Capacitors become a very famous electronic parts manufacturer and electronic parts supplier. We have below 3 sereis of varistor. And our varistor is awarded by UL, VDE, , CQC safety approvals
1) Metal Oxide Varistor
Varistors are increasingly used as the front-line solution for transient surge protection. Welcome to buy Metal Oxide Varistor from us.
2) High energy series;
3) Zinc Oxide Varistor for Power Meter: Comparing with Metal Oxide Varistor MOV Standard series, this 6KV/3KA series is upgraded series which passed 6KV/3KA approvals and designed for power meter use. This 6KV/3KA approval is significant qualification for State Grid Corporation of China. Welcome to buy Zinc Oxide Varistor for Power Meter from us.
Application of varistor:
Varistors series of UF capacitos:
UF Capacitors is your reliable Partner in China, our factory is specialized in manufacturing of Radial Leaded Varistors. After 26 years development, UF Capacitors become a very famous electronic parts manufacturer and electronic parts supplier. We have below 3 sereis of varistor. And our varistor is awarded by UL, VDE, , CQC safety approvals
Varistors are increasingly used as the front-line solution for transient surge protection. Welcome to buy Metal Oxide Varistor from us.
High energy series
Zinc Oxide Varistor for Power Meter: Comparing with Metal Oxide Varistor MOV Standard series, this 6KV/3KA series is upgraded series which passed 6KV/3KA approvals and designed for power meter use. This 6KV/3KA approval is significant qualification for State Grid Corporation of China. Welcome to buy Zinc Oxide Varistor for Power Meter from us.
Cross reference of UF Capacitors varitors
|
Photo |
Description |
UF Capacitors Series Code |
Vishay |
Littelfuse |
NIC |
Panasonic |
TDK /EPCOS |
Thinking- TVR |
|
|
Metal Oxide Varistor Radial Leaded Varistor |
VDR Series |
LA Varistor Series ZA Varistor Series |
NVR Series |
ERZE**D***K Series ERZV**D***K Series |
B722**S Series B722**Q Series |
TVR Series |
Some parameters of UF Capacitors varistors
How to Obtain a Quote from UF Capacitors?
You can easily send an email to lily@ufcapacitors.com, the engineering and sales team in UF Capacitors will help you select the correct capacitors.
