Aluminium Electrolytic Capacitors

Our aluminium electrolytic capacitor types include hybrid polymer aluminium electrolytic capacitors, leaded aluminium electrolytic capacitors, SMD aluminium electrolytic capacitors, and snap in/screw terminal types.

What are aluminium electrolytic capacitors used for?

An electrolytic aluminium capacitor, or aluminium electrolytic capacitor, often only called electrolytic capacitor, uses aluminium metal as one electrode, covered with a very thin layer of aluminium oxide as dielectric, and has an electrolyte as its second electrode.

Aluminium electrolytic capacitors are typically used in power supplies and DC-DC converters for smoothing and buffering rectified DC voltages in many electronic devices. They are also used in industrial power supplies. Aluminium electrolytic capacitors are polarized capacitors because of their anodization principle. They can only be operated with DC voltage applied with the correct polarity.

Typical applications of aluminium electrolytic capacitors with non-solid electrolyte are:

1. Input and output decoupling capacitors for smoothing and filtering.
2. DC-link capacitors in AC/AC converters for variable-frequency drive and frequency changers
3. Correction capacitors for power factor correction

What are the advantages of aluminium electrolytic capacitors?

Electrolytic aluminium capacitors provide a much higher level of capacitance for a given volume than most ceramic capacitors. This means that high value electrolytic capacitors can be relatively small. This is a significant advantage in many instances.

Electrolytic capacitors are now being used increasingly in designs that are manufactured using surface mount technology, SMT. Originally they were not used in particularly high quantities because they were not able to withstand some of the soldering processes. Now improved capacitor design along with the use of reflow techniques instead of wave soldering enables electrolytic capacitors to be used more widely in surface mount format.

How is an aluminium electrolytic capacitor different from a polymer?

The most notable difference between aluminum electrolytics and polymers is their electrolyte. Aluminium electrolytics have a liquid electrolyte while polymers have a solid electrolyte. These differences play a major role in the characteristics of each type of capacitor.

Polymers are higher cost, and have higher leakage currents and lower surge voltages. However they offer lower ESR at high frequencies, higher ripple current ratings, temperature stability, and a long life. There are other advantages and disadvantages to both types.