Film capacitors are electrical components used to store energy temporariliy in an electric field. Characterized by a time-varying dielectric constant, they are non-inductive components that are considered ideal for high-frequency applications. Also known as plastic film capacitors, they are relatively small and feature in a wide variety of electrical devices and controls. This article discusses the application field and working principle of BFC237521102, a common type of film capacitor.

Application Field

BFC237521102 film capacitors are primarily used to provide snubbing or filtering in electrical circuits. They are often used as power factor correction capacitors and are characterized by excellent low-inductance features. In addition, they are usually used in DC applications, such as DC-DC converters, boost converters, and switching power supplies, where snubbing or load bypass capacitors are necessary. They are also widely deployed in UPS systems, traction power control systems, and solar inverters, where they are used as the main power filter capacitor.

Working Principle

Film capacitors are typically composed of thin polymer films such as polypropylene (PP), polyester (PET), and polyphenylene sulphide (PPS). The construction of such capacitors involves winding the dielectric film, along with two electrically conductive metallic layers, around a bobbin, and then encapsulating the whole setup in a cylindrical case. The wires for the metallic layers (electrodes) are connected to the corresponding external terminals for electrical connection.

In BFC237521102 capacitors, the primary circuit is completed by passing an electric current through the two electrodes, creating an electric field in the dielectric layer between them, and subsequently setting up a potential difference between the terminals. This potential difference accumulates an electrostatic charge, referred to as the capacitance. When the current is reduced or disconnected, the charge will stay in the capacitance, until it is removed by a successfully conducted current. The capacitance achieved in film capacitors are typically very high compared to other types of capacitors, such as ceramic, tantalum, or electrolytic.

Conclusion

To summarize, BFC237521102 capacitors are widely used to provide snubbing or filtering in electrical circuits. They are characterized by excellent low-inductance features and are often employed in DC applications for power factor correction. The working principle of BFC237521102 capacitors involve the application of an electric current through two electrodes in order to create an electric field, which generates a potential difference between the terminals, thereby accumulating an electrostatic charge and achieving a very high capacitance.