Metalized capacitors have electrical characteristics, high stability, and long life, and can meet a variety of different applications. At present, capacitor manufacturers have been continuously improving this product to provide greater capacitance in a smaller package size. Capacitor manufacturers can optimize the characteristics of metalized film capacitors by selecting the appropriate dielectric according to the specific application. For example, polyester film shows good characteristics in common applications, with a high dielectric constant (making it the capacitance per unit volume in metalized film capacitors), high dielectric strength, self-healing characteristics, and good temperature stability sex. Among all types of film capacitors, polyester capacitors achieve the volumetric efficiency at a moderate cost, and are the popular choice for DC applications such as decoupling, blocking, bypassing, and noise suppression.





The capacitor made of metalized polypropylene film has a low dielectric loss, high insulation resistance, low dielectric absorption, and high dielectric strength. It is a long-lasting and space-saving solution, and its long-term stability is also very good. good. These characteristics make metalized polypropylene film capacitors an important choice for applications such as AC input filters, electronic ballasts, and buffer circuits. Metalized capacitors can provide rated voltages of 400VAC or higher to meet the requirements of industrial three-phase applications and professional equipment. They can also be used in switching power supplies, frequency discrimination, and filter circuits, as well as energy storage and sample and hold applications.

In addition, AC and pulse capacitors can be optimized for applications with steep pulses, such as electronic ballasts, motor controllers, switched-mode power supplies (SMPS), CRT TVs, and monitors or buffers. In these applications, a metalized polypropylene film structure with a low-loss dielectric is generally used, which can withstand high voltage and high pulse load applications under high-frequency conditions.

The principle of choosing film capacitors when designing products is usually relatively simple. For example, the EMI filter in the power line power supply product adopts a common topology and it is easy to select the capacitance value. There is no theoretical upper limit for the X capacitor placed between the main and neutral phases, but it is usually between 0.1 microfarad and 1.0 microfarad. The Y capacitor placed between the main or neutral line and the chassis ground needs to select the smallest possible capacitance to minimize the leakage current flowing to the ground.