Film capacitors and electrolytic capacitors are two types of capacitors widely used in circuits. Which one is better? What are the differences between film capacitors and electrolytic capacitors?

Appropriate capacitors are ideal; each type has its own pros and cons, and is suitable for different applications. Specific circuits require analysis; high cost-performance and suitable capacitors are preferred.

Which is better: film capacitors or electrolytic capacitors?

No polarity contrast.

Film capacitors are non-polar, so they do not require the distinction between positive and negative terminals during installation, and there's no need to worry about reversing the terminals, which could lead to an explosion. However, most electrolytic capacitors are polar (though there are also non-polar electrolytic capacitors, which are not commonly used). It is crucial to properly identify the positive and negative terminals when using them. Incorrect polarity can cause an explosion upon applying power.

2. Capacitor Lifespan Comparison.

When comparing the lifespan of capacitors, film capacitors have a significantly longer lifespan and better stability, whereas electrolytic capacitors have a relatively shorter lifespan. Especially now, the price difference for electrolytic capacitors of the same model from different manufacturers can be about double, and the lifespan of poor-quality electrolytic capacitors is even shorter.

3. Temperature Characteristics.

Whether it's electrolytic capacitors or film capacitors, temperature affects their electrical performance. Film capacitors have a wider operating temperature range, typically -40℃ to +105/110℃, and exhibit good temperature characteristics. They can be used normally in extremely cold areas or in places that are very hot during summer.

The temperature coefficient of electrolytic capacitors generally refers to the ratio of the change in the electrolytic capacitor within a specified temperature range to the rated capacitance per degree Celsius of temperature change. The typical temperature range for electrolytic capacitors usually has an upper limit of 105°C or 85°C, with some high-temperature-resistant electrolytic capacitors having a limit of 125°C or 135°C. The lower temperature limit is generally -25°C, -40°C, or -55°C. The temperature resistance of different electrolytic capacitors with various dielectric materials varies according to their withstand voltage capabilities.

Electrolytic capacitors are sensitive to temperature. Whether the ambient temperature is too high or too low, it can lead to a decrease in capacitance or even damage. The temperature of electrolytic capacitors is directly related to their lifespan. As is widely known, the lifespan of electrolytic capacitors is greatly influenced by temperature. Generally, the higher the operating temperature, the shorter the lifespan.