Ceramic capacitor is the most widely used capacitor in electronic equipment, accounting for about 50% of the total number of capacitors used.
Suitable models should be selected according to the working condition and environmental conditions of the line, and the main parameters should meet the requirements of the line.
(1) in the high frequency resonant circuit, in addition to the requirements of capacitor loss is small, but also requires a good temperature stability of capacity, usually choose a class 1 porcelain dielectric capacitor, its capacity basically does not change with the temperature, but its capacity is only in a few PF ~ several hundred PF between.
(2) For the capacitors of low frequency coupling, bypass and filtering, small size and low cost are often considered, and the temperature stability requirement of loss and capacity is not high, so generally 2 types of porcelain capacitors can be used, and their capacity range is wide.
(3) Although ceramic capacitors have a larger voltage tolerance than film capacitors and electrolytic capacitors, they are not allowed to be used under conditions exceeding their rated voltage, otherwise the migration of metal ions in the electrode under the action of strong electric field and then in the ceramic medium will accelerate and lead to a decrease in the insulation resistance of the capacitor and affect the reliability of the long-term work of the machine.
14D270K Epoxy Resin Film Zinc Oxide Varistor

14D270K Epoxy Resin Film Zinc Oxide Varistor

(4) for high temperature and high voltage conditions of the capacitor, should pay attention to the use of high insulation resistance of the product, to prevent leakage increases due to the vicious cycle leading to capacitor failure. Usually insulation resistance IR ≥ 10000MΩ. for example: in the CRT acceleration pole filter position should be selected with sufficient insulation resistance; for line reverse circuit, because of the capacity of the stability and loss requirements are high, can only use a class 1 high-voltage porcelain capacitor, as a polypropylene capacitor capacity compensation capacitor, otherwise it will cause serious quality risks.
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