Product ID: 269ab3
Table of Content
Ceramic vacuum capacitors use vacuum as dielectric capacitors. This capacitor electrode group is a high-conductivity oxygen-free copper with a set of concentric cylindrical electrode formed through a set of high precision molds is sealed in a vacuum container. Therefore, its performance is stable and reliable, no arcing, corona and other phenomena.
- The performance characteristics of the ceramic vacuum capacitors
- The structural classification of ceramic vacuum capacitors
- The main technical parameters of the ceramic vacuum capacitors
- Ceramic vacuum capacitor applications
- The application of technical conditions of the ceramic vacuum capacitors
- Cooling of the ceramic vacuum capacitors
- Ceramic vacuum capacitor storage
- Ceramic vacuum capacitor transport
- Ceramic vacuum capacitor voltage test
- The installation of ceramic vacuum capacitors
- Ceramic vacuum capacitor to maintain
The performance characteristics of the ceramic vacuum capacitorsCeramic vacuum capacitors compared to other dielectric capacitors, high pressure, small size, low loss, stable and reliable performance. Unique at the following aspects:
- Rated voltage - due to the vacuum of high dielectric strength, combined with features such as dust, moisture, vacuum capacitor has a large value of the rated voltage for a certain size and capacity. It can be up to hundreds of thousands of volts.
- Low loss, large rated current - due to the capacitor using vacuum medium and low loss insulation shell and oxygen-free copper electrode structure, in the general case of convection cooling, even at very high frequencies, but also through a lot of RF current. If using special water cooling structure, the RF current of up to thousands of amperes.
- Save space - vacuum capacitors is the smallest, for a given capacitance and rated voltage.
- Wide adjustment range - maximum capacity and minimum capacity ratio as high as 150: 1, by a few pF to several thousand pF, becomes the ideal components for a wide tuning range.
- Over voltage self-healing capabilities - can withstand transient overvoltage, while the other capacitor will cause permanent damage.
- High altitude capability - vacuum seal ceramic vacuum capacitors at high altitudes without resulting in reduced its characteristics.
The structural classification of ceramic vacuum capacitorsCeramic vacuum capacitor structure can be divided into two categories: the location of the two electrode groups of the capacitor is fixed - Fixed ceramic vacuum capacitor; two electrodes in the group of capacitors one electrode group position is adjustable - adjustable ceramic vacuum capacitors.
The main technical parameters of the ceramic vacuum capacitors
- Capacitance-Fixed capacitors: the capacitance nominal value greater than 50pF, which allows deviation of ± 5%; 5 ~ 50pF, the allowable tolerance of ± 10%. Variable capacitors: the maximum capacity allowable deviation ± 5%; minimum capacity less than or equal to the nominal value.
- Peak test voltage-Peak test voltage can increase the breakdown in the capacitor (the maximum performance for internal or external flash), the frequency voltage. By the capacitor in the voltage under test is a means to determine the overall status of the capacitor.
- RF operating voltage-RF working voltage refers to the continuous increase in the capacitor will not affect its exposure to the maximum transient overvoltage peak RF voltage. It is usually 60% to 70% of the peak test voltage rating; this value is recommended for use in the selection of the capacitor safe value.
- Maximum RF current-Maximum RF current is allowed in the operating voltage, the maximum capacity of a certain frequency of the RF current through the capacitor.
- Dielectric loss-The dielectric loss is less than or equal to 10X10-4.
- DC leakage current-Capacitor DC leakage current is less than 15uA.
- Torque-for adjustable ceramic vacuum capacitors, the torque of the capacitor should be consistent with the provisions of the product standards.
Ceramic vacuum capacitor applications
- Radio and communications equipment-Ceramic vacuum capacitors are used as tuning, coupling, filtering, DC blocking and other components in the medium wave, short wave and ultra-short wave transmitter.
- Semiconductor manufacturing equipment-For the plasma deposition and etching equipment
- High-frequency industrial equipment-For high-frequency dielectric heating and welding
- Medical equipment-Medical analyzers and therapeutic apparatus
- High Energy Physics-High-energy particle accelerators and other
- The electrical equipment-For the dielectric loss test equipment
The application of technical conditions of the ceramic vacuum capacitors
- The maximum allowable operating temperature-Capacitor maximum allowable operating temperature: 120 ° C.
- Cooling mode-Unless otherwise requested, is the natural air convection.
- The installation location-Random
- Temperature Coefficient-The capacitor's temperature coefficient is less than or equal to 100X10-6.
- The direction of rotation of the variable capacitor capacitance increases-Counterclockwise.
- Collision-Peak acceleration: 100 m / s2; pulse duration: 16ms; the number of collisions: 10000.
- Vibration-Vibration direction: according to the product standard requirements; frequency range: 5 ~ 55 Hz; amplitude values: 20m / s2 or in accordance with product; duration: the product standards.
Cooling of the ceramic vacuum capacitorsCapacitor cooling in different ways by the RF current is not the same. Its cooling method has the following three:
- Natural convection cooling
- Forced air cooling
- Loop water cooling
Ceramic vacuum capacitor storage
- The capacitor storage conditions: axial vertically, clean, dry environment.
- The capacitors store more than three months, the high pressure experienced to ensure that the capacitor voltage capability.
- Water-cooled capacitor in the high pressure experienced should be to ensure that clean the water of the capacitor.
Ceramic vacuum capacitor transportThe transport of the capacitor should be as far as possible with the original packaging, and the variable capacitor should also be transferred to capacity and turn the screw callback 3 to 4 laps.
Ceramic vacuum capacitor voltage test
- The capacitor test AC voltage 50Hz/60Hz AC porcelain wall should not have water, gas, oil, dirt; to prevent the external breakdown should ensure that, before the test. The adjustable capacitor should be set to the maximum capacity side. The test voltage for the peak test voltage
- Capacitor DC voltage test, porcelain wall should not have water, gas, oil, dirt, adjustable capacitor should be set to the maximum capacity side, the DC voltage test should be conducted after the exchange of qualified before the test.
- The test voltage for peak operating voltage: later during the DC test, the capacitor before the next operation must fully discharge the capacitors in the DC test will be some of the load current, this will be very dangerous.
The installation of ceramic vacuum capacitors
- The capacitor parametric test should be carried out prior to installation to ensure that qualified products, and to ensure the capacitor appearance clean.
- Cooling of the capacitor is determined by the RF current through the capacitor.
- The capacitor electrode in one end must be flexible, short, wide copper strip connection.
- During the installation process, the capacitors should be avoided torsion and bending forces acting to prevent the deformation of the ceramic and metal seal at the
Ceramic vacuum capacitor to maintain
- Usually normal circumstances, the capacitor does not require much maintenance. Capacitors need to stay away from dust, to prevent dust backlog, keep the environment dry and unglazed porcelain shell to clean with detergent and clean water.
- Turn the screw to regular oil or special grease for lubrication.