With advancing technology, electronic products are becoming more numerous and multifunctional. Take smartphones, for example—they can make calls, video chat, and even stream TV. These functions rely on various electronic and non-electronic components inside the device.
Inside a smartphone, there are processors, IC chips, batteries, capacitors, and more. While most people know what processors, ICs, and batteries are, capacitors are less familiar. Many mistakenly think capacitors are like power banks that can charge the phone.
Capacitors are not power banks. They are small components that cannot supply energy to charge a device. Their primary functions are filtering, coupling, and bypassing signals.
Understanding Film Capacitors
Film capacitors are made of plastic film as the dielectric with metal layers as electrodes. They offer:
· High voltage tolerance
· Low loss
· Long lifespan
Film capacitors are widely used in power supplies, lighting, and renewable energy applications. Despite their small size, they should not be treated as energy storage like batteries.
How to Select the Rated Voltage
The rated voltage of a film capacitor indicates the maximum DC or AC voltage it can safely withstand under specified environmental conditions. It is not the voltage the capacitor should operate at continuously.
To ensure long-term reliability and protect the capacitor from unexpected overvoltage or surges, the rated voltage should be 25–30% higher than the actual working voltage.
Conclusion
Understanding the role of film capacitors prevents misuse and ensures reliable circuit performance. Remember: capacitors store charge briefly for filtering or coupling—they are not power banks. Selecting the correct rated voltage is essential for safe and stable operation.
This article is provided by JYH HSU (JEC) Electronics. JEC is a research, development, production, and sales-oriented company specializing in manufacturing and selling various electronic components such as capacitors and resistors.
Post time: Jan-29-2026