What are electrolytic capacitors?

Electrolytic capacitors are a special type of capacitor device consisting of electrolytes and using them to maximise their capacitance. These types of capacitors are primarily used in DC power supplies. The compact sizes of electrolytic capacitors enable them to minimise the ripple voltage. 

Electrolytes contain a significantly large concentration of ions and store electrical charge in the anodes and cathodes upon the application of a voltage across their terminals. 

Types of electrolytic capacitors

Electrolytic capacitors can be chiefly categorised into three types. These are:

1. Aluminium electrolytic capacitors

These types of electrolytic capacitors are polarised and possess aluminium anode and cathode foils. Aluminium capacitors have the lowest leakage current among all other types of capacitors. 

2. Polymer electrolytic capacitors

These types of electrolytic capacitors feature a conductive polymer as the electrolytic material and possess high conductivity, high ripple current capability, extended temperature range, and durability. 

3. Hybrid electrolytic capacitors

These types of electrolytic capacitors are polymer and aluminium hybrid capacitors, possessing both wet electrolytes and solid polymers. Having both, hybrid electrolytic capacitors offer high tolerance for ripple current, high endurance, and reliability. 

Applications

Electrolytic capacitors have extensive applications, which include low-pass filters, audio amplifier circuits, power supplies, and more. They are primarily used in filtering h amplification applications. For instance, electrolytic capacitors can be used to smoothen input and output signals, minimise ripples, and reduce hums.