Film Capacitors

Film capacitors (BFC237026562) are capacitor types that are commonly used due to their superior temperature characteristics and stability. These capacitors consist of a material such as polyester or metalized polyester placed between two conductive electrodes. This type of capacitor is mainly used in applications such as high frequency filtering and decoupling, high-end audio or ultra-low-noise power supplies. Additionally, they provide excellent ESR, ESL, and high current ratings.

Application Field

Film capacitors are mainly used in applications where voltages greater than the working voltage of electrolytic capacitors are present, as well as for AC applications due to their low reactance. Furthermore, these capacitors are used for high frequency energy storage and to reduce voltage fluctuations in power supplies. They are also used for high inductance roles, such as noise filtering and decoupling, and as non-inductive resistors or snubbers. Film capacitors are also effective in applications related to medical equipment, motor control, digital circuits, and high power output devices.

Working principle

The inner layer of the film capacitors is composed of ethylene propylene rubber or metallized polyester, which acts as an insulation film. The two electrodes are then connected to the respective regions of the film and it is the force of these connections that determines the capacitance. The electrical charging is stored between the plate made from ethylene propylene rubber or metallized polyester and the ground. This causes a certain amount of electrical energy to be stored and released each time the capacitors are connected to a circuit.

When the capacitor is connected to a circuit, an electric field is created and charges move from one plate to the other, resulting in a buildup of electric potential. This electric potential is then further increased by the application of a voltage, which draws electrons towards the surface of both plates. As the electrons move through the film, they create electrostatic attraction, which in turn increases the capacitance. Upon removal of the voltage, the electrons move back to the initial, neutral state, thus releasing the electrical charge.

Film capacitors are a cost-effective and reliable alternative compared to electrolytic capacitors, offering better temperature and frequency characteristics while maintaining strong insulating properties.