Capacitors and their type

There are various types of capacitors. Mainly there are two types of capacitors fixed capacitor and variable capacitor. They are classified depending upon their polarity like polarized and non-polarized. The positive and negative terminals marked on the capacitors. The polarized capacitors can be connected in circuits only in one particular way were the non polarized capacitors can be connected in the other way of the circuits. The capacitors have different characteristics and specifications in electrical. Based on their characteristics and specifications they can be used in different applications.

Types of capacitors

1. Electrolytic capacitors

These are polarized capacitors. The anode or the positive terminals is made up of metal and through anodization the oxide layer is created. So this layer acts as an insulator. There are three types of electrolytic capacitors which is used for the different type material. And these can be classified as are as following
Aluminum electrolytic capacitors

Tantalum electrolytic capacitors

Niobium electrolytic capacitors

A. Aluminum electrolytic capacitors

In this type of capacitors the anode or positive terminal is made up of aluminum and this acts as dielectric. These capacitors are much cheaper than other type of capacitors. They have very large tolerance

B. Tantalum electrolytic capacitors

In these capacitors the metal is used as an electrode. These types are available in lead type as well as in chip form for surface mounting capacitors have (10 nf to 100 mf) capacity. It has high volumetric efficiency. They have low tolerance. They are very stable and reliable.

C. Niobium electrolytic capacitors

These are not popular as much the Aluminum electrolytic capacitors and Tantalum electrolytic capacitor. It has very lowered price or cheaper in rate.

2. Ceramic capacitors

These are not popular as much the Aluminum electrolytic capacitors and Tantalum electrolytic capacitor. It has very lowered price or cheaper in rate.

• Class I-High stability and low losses

1. 1. very accurate and stable capacitance
   2. very good thermal  stability
   3. low tolerance (I 0.5%)
   4. lower leakage current
   5. Resistant and oscillators

• class II-lower accurate and stability comported to class-I capacitors

1. 1. high volumetric efficiency then class-I capacitors.
   2. changes with biasing voltage

3. Film capacitors

• In this film capacitors the plastic film is used as a dielectric material. There are different type like polyester poly propylene, polystyrene. It has high stability and good reliability its voltage rating is I O U to 10 KV these are available in the range of PF and MF.

4. Super capacitor

• It is also known as ultra capacitor they are storing large amount of charge. The capacitance range vary from few farads to 100 farads the Voltage rating is between 2.5 to 2.9

5. Mica capacitor

• These are accurate and provide a good temp stability .they are used in RF applications and also high voltage applications. They are costly that’s what these are replaced by other capacitor

6. variable capacitor

• It is also known as trimmer capacitor they are used for the calibration of equipment or the manufacturing or servicing. It is possible to change the certain range. There are two type of trimmer capacitor.
• Ceramic and Air trimmer capacitor.
• The minimum capacitor is around 0.5 PF, but it can be varied up to 100PF.
• These capacitors are available for voltage rating of up to 300v these capacitors are used in the RF application oscillators and tuning circuits.