A Secret to Say About Electrolytic Capacitors

Capacitors as electrical and electronic components are very familiar to us electricians. Power capacitors in reactive power compensation, filter capacitors in the DC main circuit of the inverter, and capacitors with various shapes on various electronic circuit boards are also Or the CBB capacitor in the electric fan in our life, etc., you always have contact.

There are many types of capacitors. Today, I will focus on the electrolytic capacitors with the widest range of applications and the most versatile uses. Electrolytic capacitors are currently divided into two categories, aluminum electrolytic capacitors and tantalum electrolytic capacitors, of which aluminum electrolytic capacitors are the most common. The biggest difference between electrolytic capacitors and other types of capacitors is that-electrolytic capacitors have a polarity of +,-. It must be noted in the use of DC circuits. Once the polarity is exploded, it is inevitable! In addition, electrolytic capacitors do not appear in AC circuits.

Among the aluminum electrolytic capacitors we have contacted, I don't know if anyone has noticed that there are "+", "K", "Y", etc. on the top of some electrolytic capacitors (the voltage is more than 16V or the capacity is more than 100uf). Shape indentation, so what use is this indentation?

In fact, this indentation is designed for explosion-proof capacitors. When the circuit where the aluminum electrolytic capacitor works is overvoltage, short-circuit breakdown, etc., or the electrolytic capacitor itself has caused a capacitor explosion, the capacitor tip is more difficult due to the existence of the indentation. The other places are thinner, so the capacitor will explode from the top instead of blowing up, preventing the accident from expanding!

The filter electrolytic capacitors used in high-power DC circuits such as inverters are generally used in an inverted state. Once these power-grade aluminum electrolytic capacitors explode, they are no less powerful than grenades, so in order to facilitate maintenance personnel to understand the capacitors in time. For safety, a small "explosion-proof hole" is usually set near the two poles of the capacitor for easy observation. If this hole bulges, the capacitor should be replaced immediately!