Introduction to the Functions of Polypropylene Film Capacitors

Polypropylene film capacitors—also commonly referred to as "CBB capacitors"—constitute a broad category of capacitors encompassing a wide variety of types. What are some of the most frequently used CBB capacitors, and what specific functions do polypropylene film capacitors serve?

A CBB capacitor is a type of capacitor constructed by winding together aluminum foil electrodes and a polypropylene film dielectric (while the specific internal dielectric may vary among different CBB models, the core material invariably consists of polypropylene film), utilizing a non-inductive structure. These capacitors are typically encapsulated in epoxy resin or housed within a plastic casing. Characterized by a high dielectric constant, a wide operating temperature range, robust overvoltage resistance, excellent frequency response, and effective self-healing properties, they offer a long service life, high stability, and relatively low cost. Consequently, CBB capacitors are applicable across numerous fields and enjoy a remarkably broad scope of application.

CBB22 capacitors are the most widely used type.

Of all CBB capacitors, CBB22 capacitors are the most widely used. CBB22 capacitors have many names, such as CBB21 and MPP capacitors, but they are essentially the same; the difference lies only in the naming conventions used by different manufacturers.

CBB22 capacitors are inexpensive and offer high cost-effectiveness, hence their widespread use. They are primarily used in high-frequency, DC, AC, and high-current pulse applications. For example, they are widely used in common lighting fixtures and power supplies, and can also be used in RC step-down circuits.

MPB Boxed Polypropylene Film Capacitors

MPB capacitors, also known as CBB21B capacitors, are very similar to CBB22 capacitors. The only difference is that CBB22 capacitors are encapsulated in epoxy resin, while MPB capacitors are encapsulated in a plastic shell. Relatively speaking, MPB capacitors have stronger high-temperature and high-humidity resistance and a longer lifespan, but they are slightly more expensive than CBB22 capacitors. Their function is the same as CBB22 capacitors.

CBB81 High-Voltage Resonant Capacitor

While CBB22 capacitors are inexpensive, their performance is insufficient for high-voltage, high-current circuits. In such cases, CBB81 high-voltage resonant capacitors can be used. CBB81 capacitors are suitable for high-frequency, DC, AC, and pulsed high-current applications, such as lighting fixtures, power supplies, displays, and horizontal/reverse circuits in color televisions.

MMKP82 Double-Sided Metallized Resonant Capacitor

The MMKP82 capacitor is an upgraded version of the CBB81 capacitor. Their function is essentially the same, except that the CBB81 capacitor is encapsulated in epoxy resin, while the MMKP82 capacitor is encapsulated in a plastic shell.

Because the MMKP82 capacitor uses a special double-sided metallized polypropylene film, it is relatively smaller, has better high-temperature and high-humidity resistance, and a longer lifespan. Its function is the same as the CBB81 capacitor.

Other CBB capacitors:

CBB20 axial capacitors are used in audio circuits and ultrasonic mask machines.

CBB60 is suitable for starting and running unidirectional motors powered by 50/60Hz AC power.

CBB61 capacitors are mostly square in shape and are mainly used as starting capacitors in electric fans, range hoods, and air conditioner fans.

There are actually many other types of CBB capacitors, but their usage is relatively limited, so we will not introduce them one by one.