The pressure sensitive resistance is a kind of common protection element. It can be divided into the patch based pressure sensitive resistor (MLV) and the plug-in type voltage sensitive resistor (MOV). The plug-in is a kind of metal, which can quickly suppress surge over-voltage, and it is also called ZOV. It is made of ceramic sintering technology, and then in the outside of the package of resin from the metal Zinc Oxide pressure sensitive resistance. The patch is the use of semiconductor ceramic laminated chip manufacturing technology, in the country to the FPV series as the representative of electronic dance. Taking MOV as an example, this paper introduces the characteristics and application of the pressure sensitive resistor, the matters needing attention in the application of the circuit, the parameters of the pressure sensitive resistance, the calculation formula of the voltage and the selection of the proposal. This paper provided by the official electronic dance. Buy Electronic tage varistor, please consult the official website from
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Characteristics of pressure sensitive resistance:
It has fast response speed, the response time is less than 25nS;
It is a kind of voltage limiting type. It is a kind of surge voltage protection device which is stronger in the line;
The voltage specifications from 18V~1800V, inrush current capability Purnell ranging from hundreds of amperes to tens of amperes, the largest single up to 70KA;
Package size diversification, varistor Phi 5, Phi 7, Phi 10, Phi 14, Phi 20, Phi 25, Phi 32, Phi 40, Phi 53, 34S and TMOV type E type /N type /M in different specifications;
Larger capacitance value;
Non polarity, convenient and simple installation;
Easy aging attenuation;
Dedicated to the power supply and the low frequency communication signal line protection.
Circuit design and notice of the pressure sensitive resistance:
As the varistor aging decay, in order to fully improve the reliability and service life of the varistor varistor, usually with ceramic gas discharge tube or glass discharge tube combination supporting the use of.
As the varistor failure usually a short-circuit state, thus easy to fire safety affect the product, there is a special Brightking with temperature fuse thermal trip type TMOV varistor.
Use of pressure sensitive resistors
Widely used in consumer power products and power system products in the protection of semiconductor and sensitive devices, in case of IC from the impact of transient overvoltage and damage.
Power supply line, switching power supply, circuit breaker, etc..
Multifunctional electric meter power supply, electronic ballast, electronic ballast, AC/DC converter, charger, instrument and meter, Vcc protection.
Brightking varistor products meet RoHS WEEE corresponding terms and passed the inspection and testing institutions accordingly, meet the corresponding test standard: UL1449 third edition, IEC60950-1, IEC61000-4-5, IEC61643-331:2003, VDE, CSA, CQC and other standards.
Pressure sensitive resistance parameter:
Description of the parameters of the pressure sensitive resistance:
VAC -- the maximum continuous working voltage; VC -- the limiting voltage under the IP current;
VDC - the maximum continuous DC resistance voltage; IP - 8/20 a pulse current S;
V1mA -- Based on the 1mA test under the pressure sensitive breakdown voltage; 8/20 S IMP;
E -- 10/1000 S Joule energy; Ctype -- capacitance value.
Selection principle of pressure sensitive resistance:
1, the calculation formula of the pressure sensitive voltage
General can be obtained by the following formula: U1mA=KUsp/ (1-A) (1-B) calculation.
K for the power quality of the use of the relevant coefficient, generally take K= (1.1 ~ 1.6), better quality of the city‘s better power quality, poor quality of rural areas (especially the mountains) is desirable.
Usp for the power supply voltage peak, the AC power supply Usp=1.414*Uac (effective value), the DC power supply Usp=Udc.
A for the aging coefficient, generally take 0.1.
B for the voltage sensitive voltage tolerance value, generally 0.1.
2, the selection of voltage sensitive recommendations.
According to the above formula
1, 220V AC power supply lightning surge protection should be used to choose a voltage sensitive voltage of 430V ~ 620V of the pressure sensitive resistance is appropriate.
2, 110 AC AC power supply lightning surge protection should be used as the varistor voltage 200V ~ 300V varistor is suitable to use a high breakdown voltage, can reduce the failure rate, can also be used together with the discharge tube, to prolong the service life of the effect.
3, pressure sensitive through the flow of the selection
According to customer‘s product lightning test level of the requirements of the selection, to determine the size of the selected pressure sensitive resistance.