High voltage ceramic capacitors, that is, the use of high voltage ceramic capacitors in the power system, such as power system measurement, storage, partial pressure and other products, will be used in high-voltage ceramic capacitors. High voltage ceramic capacitors have been widely used and the status of light in the LED lamp industry, high voltage ceramic capacitor with high dielectric constant ceramic capacitor on a titanium oxide, barium titanate is extruded into round tube, disc or disc as the medium, and the sintering method of silver plating on ceramics as electrode made.
The characteristic of the high voltage ceramic capacitor with high voltage DC resistance, suitable for high pressure by-pass and coupling circuit, low loss high pressure wafer which has a low dielectric loss, especially suitable for use in a television receiver and scan circuit. As long as the high voltage ceramic capacitor for high frequency, high voltage ceramic capacitor depends on the use of what the occasion, the typical role can eliminate high frequency interference. High voltage ceramic capacitors used in the field of high power and high voltage require the characteristics of small size, high voltage resistance and good frequency characteristics. In recent years, with the development of material, electrode and manufacturing technology, the development of high voltage ceramic capacitor has made great progress and has been widely used. High voltage ceramic capacitor has become one of the indispensable components of high power and high voltage electronic products. The use of high voltage ceramic capacitors is mainly divided into power supply, power distribution system and power equipment to deal with pulse energy equipment. Because of the special nature of the power system, AC high voltage, high frequency, in the outdoor environment (-40 degrees to +60 degrees), lightning voltage / current, and so on a variety of factors, resulting in high voltage ceramic capacitor has been in a dilemma in the development and production in the harsh environment, requires a capacitor with superior stability, the rate of change small; at the same time, measurement, storage, partial pressure of product requirements of high precision, which is of high voltage ceramic capacitor of this environment is partial discharge, partial discharge is very demanding: PD is zero.
1 capacity loss with temperature frequency with high stability
2 special series structure suitable for high voltage pole long working reliability
3 high current climbing rate and is suitable for high current loop non inductive structure.
- high voltage ceramic capacitor and high voltage ceramic capacitor features contrast: characteristics of high voltage ceramic capacitor 1 does not require certification
2 ultra high pressure can reach 7KV in high rare,
3 print and Y capacitors than the need to put the national certification on the surface of the product,
4 voltage can be up to 16V
5, the highest pressure is 2.5 times the general production is the standard voltage of the AC breakdown voltage characteristics of the standard type A material, the breakdown voltage of the ceramic capacitor. With the gap length G (wafer radius and electrode radius difference) relationship. The diameter of the capacitor is 18mm, and the dielectric constant of the material is 1460 "A". Test conditions for 25 DEG C, applying the 50Hz AC voltage, the voltage rise rate of ZkV/s high voltage ceramic capacitor characteristics:
Commonly used in high pressure occasions.
There are ceramic I class III, II type porcelain, the classification of porcelain,
I ceramics, NP0, temperature characteristics, frequency characteristics and voltage characteristics are good, because the dielectric constant is not high, so the capacity is not large;
II ceramics, X7R, temperature and voltage characteristics are better;
III ceramics, the dielectric constant is high, so the capacity can be very large, but the temperature and voltage characteristics are not good.
Generally small size ceramic capacitor.
In addition, an important feature is emphasized:
Ceramic capacitor breakdown, short circuit is often state. (this is its weakness)
The film capacitor failure, generally open circuit state.
High voltage ceramic capacitor and high voltage ceramic capacitor function is basically the same, some of the details will be different. So in the use of time should also pay attention to performance.
High voltage ceramic capacitor, a line, commonly known as DIP class, this class of products from 16VDC to 100KV are produced, but mainly refers to the direct current, and is the lead type.
Ceramic capacitors two, line type are offbeat AC ceramic capacitors, that is, generally refers to the 250VAC Y2 safety capacitor, and the 400VAC Y1 AC safety capacitors. It is obvious from the name that the voltage of this kind of capacitor is the AC voltage, and it is safe to have about ten countries. Outside the container, the voltage of the other lead type ceramic capacitor is generally referred to as dc.
Three, SMD ceramic capacitors, commonly known as SMD class, the specification of such capacitors in general, such as 020104020603080512061210.. English - chip capacitor is MLCC, voltage from 6.3VDC to 2KV above all, of course, the higher the voltage, the price is more expensive.
Four, bolt type high voltage ceramic capacitor. This type of capacitor is generally resistant to high voltage, in the power system is often referred to as AC voltage. Such as 40KV102K, 40KV103K, 40KV153K and so on, many models, but the voltage is not dc. Because our home, or the use of electricity is used in factories and enterprises ah! Technical content of this kind of capacitor is very high, is often a lot of enterprises can make this kind of shape, but has no way to make the quality of the requirements of the guests, the reason is: first this kind of product requires higher AC voltage, and most of the factory is the subject of DC voltage, so, in the sample period was eliminated secondly, this kind of; high voltage ceramic capacitor for low partial discharge, partial discharge quantity is large, the actual value of the capacitor voltage is lower, therefore, PD is the best standard to measure the quality of a capacitor; third, ultra high frequency capacitor, lead type general also want to do frequency the robe high, and this type of bolt is higher requirements. Finally, this kind of capacitor is very strict to the material, because the loss and temperature coefficient of different materials, dielectric coefficient is not the same.
High voltage ceramic capacitor
High voltage generator to use a lot of high voltage ceramic capacitor and large capacity high-voltage capacitor. Traditional use, the guests generally use high voltage film capacitors, but with the advantages of ceramic capacitors continue to reflect, in the future, thin film capacitors will be less and less in the high-voltage generator.
The advantages and disadvantages of high voltage film capacitors and high voltage ceramic capacitors are mainly the following points:
1 high voltage ceramic capacitor for longer life. The life of the film capacitor is three years, good electrical products will not exceed 5 years. The high voltage ceramic capacitors are different, for example, the capacitor on the public commitment: according to 20 years of design, at least to ensure the use of the past 10 years.
2 high voltage ceramic capacitor less resistance. This is determined by the structural characteristics of each. The internal resistance of high voltage ceramic capacitor is very small, and the thin film capacitor is adopted as winding way, thus causing the resistance is too large. Another negative influence brought by the large internal resistance of this kind is in the process of repeatedly charging and discharging capacitor, the resistance will continue to become larger, and in a certain time the capacitor in the circuit failure.
3 relatively high voltage of high voltage ceramic capacitor. The capacitance of the film capacitor is relatively high, and the operating voltage is not as high as that of the ceramic capacitor;
4 has the advantage also has the shortcoming, the ceramic capacitor capacity is small.
High voltage ceramic capacitor, test method
High voltage ceramic capacitor reliability test, also known as aging test, life test, including many aspects of the test content:
1, series resistance test, insulation resistance test;
2, tensile testing, that is, the bonding strength of the chip and the chip;
3, positive and negative temperature change rate test, that is, -40 degrees to +60 degrees, the capacitance change rate;
4, the aging test, high voltage ceramic capacitors in the simulated operating conditions of the environment for 30~60 days, testing its attenuation of its various parameters change;
5, withstand voltage test, including the rated operating voltage of 24 hours of work test; also includes the breakdown voltage, that is destructive testing, capacitance is the breakdown of the critical voltage is the breakdown voltage.
6, PD test, that is, partial discharge test;
7, life test, which is based on the aging test, then the high frequency capacitance test punching fast charging and discharging current, note the charge and discharge times were obtained, the charge discharge life, life is obtained after long time aging.
High voltage ceramic capacitor, self recovery period
High temperature sintering is one of the most important processes of high voltage ceramic capacitors. After one hundred tons of die casting, as well as the sintering temperature of more than 1 thousand degrees, high voltage ceramic capacitors inside the chip, the structure of the molecules between the crystal structure. The next 6 hours of high-temperature baking, and heat preservation for 7 hours, completely disrupted the internal structure of the crystal.
Then, in order to restore the structure of the chip, the stability of the chip characteristics, high voltage ceramic capacitors need time to recover. Natural recovery (stored at room temperature) for 60 days or more. Moreover, the storage of a year and two years of storage products, with a long time for outstanding performance. Therefore, the recovery period is long, the performance of the capacitor is very helpful, there is no recovery period of the capacitor, the voltage and current performance is poor. It is found that the loss angle of the high voltage ceramic capacitor will be smaller and the high frequency characteristic will be better.
High voltage ceramic capacitors, units and symbols
And its basic unit is: F (method), and F (micro method), pF (skin), another with a relatively small unit, that is: nF, the capacity of F is very large, so we generally see is F, nF, pF the unit, instead of F unit. The conversion between them is as follows:
The capacitance of the symbol is also divided into domestic and international standard representation of electronic notation, but the capacitance symbol in the domestic and international express are similar, the only difference is in the polarity of the capacitor, the domestic is an empty basket below a horizontal line, and international is an ordinary capacitor and a "+" sign on behalf of the positive.
High voltage ceramic capacitors, the use of attention
1 working voltage DC rated voltage of capacitor in the AC circuit or the ripple current in the circuit, make sure the applied voltage Vp-p or contains a DC bias voltage Vo-p value was maintained at the rated voltage range. If the voltage applied to the circuit, may produce abnormal voltage temporarily by resonance or switch when starting or stopping please be sure to use the capacitor rated voltage range contains the abnormal voltage.
2 working temperature and heat generating (for B/E/F characteristics) the surface temperature of the capacitor should be maintained at the rated temperature range below. Be sure to allow for self heating of the capacitor. The capacitor in the high frequency current, may be due to the dielectric loss of hair from the heat impulse current when the applied voltage should be used in. The authigenic heat load does not exceed 20 DEG C at 25 C ambient temperature conditions. The measurement should be used when the small heat capacity of 0.1mm (K) of the thermocouple, and the capacitor should not be subjected to heat or temperature fluctuations around other elements. Overheating may lead to reduction of electrical characteristics and reliability of the container (do not measure. In the cooling fan. Otherwise it is impossible to ensure the accuracy of measurement data)
3 withstand voltage test conditions
(1) test equipment
AC withstand voltage test equipment shall have the capability to produce a 50/60Hz like sine wave
If a deformed sine wave is applied or an overload voltage exceeds the specified voltage value, the fault can be caused
(2) voltage plus method
When applied voltage, wire or capacitor terminals should be output and withstand voltage test equipment is connected firmly; and then the voltage increased from near zero to the test voltage. If the test voltage is increased gradually from near zero but directly applied to the capacitor, is applied when should contain zero. At the end of the test. The test voltage should be reduced to nearly zero; then the capacitor lead terminals or from the output voltage resistance test equipment end off. If the test voltage is from near zero gradually increased but directly applied to the capacitor, it is possible to surge voltage, which is caused by the fault of.0V * refers to zero voltage sine wave voltage through the sine 0V position.
4 fail safe
When the capacitor is damaged, failure may cause a short circuit. In order to avoid electric shock, short circuit in smoke, fire and other dangerous situations, please fuses and other components used in the circuit to set up automatic fault protection function.
The use of this product, such as ignoring the warning, in severe cases may cause short circuit, and cause smoke or partial dispersion.
Contact: Tina Zhang
Add: NO.88 BAIHUYAN Road Jimei District, Xiamen, Fujian, P.R.China