Types Of Capacitors And Their Applications.

           

Capacitors are found on almost all circuits boards and their presence is ubiquitous in mordern electronics.They are very cheap to manufacture because their raw materials are abundant.

It consists of two metal plates commonly aluminum tin,separated by a dielectric substance.

 Different types of capacitor's capacitance can be tailored by their size, dielectric materials used and also the nature of the metal plates.         Capacitors importance in circuits is beyond what we think of,they are used in making memory cards,integrated circuits and SIM chips. A memory chip is made up of bytes,a bytes is also made of a transistor and a capacitor.The capacitor acts as a storage element while the transistor acts as the switch.

        Types of capacitors.

Capacitors are basically of two types namely,polarised and non-polarised.They are grouped into fixed and variable,fixed are of two types, electrolytic and non electrolytic.

(i) Electrolytic:

They are the most common, they have high tolerance and also they are available at a working voltage of 500v,but their highest capacitance are not available at high voltage.

Electrolytic capacitors are of two types.

(a) alluminum capacitor

their metal plates are made of aluminum foil and is the most common type of electrolytic capacitors.

(b) tantalium capacitor

they are much durable than aluminum capacitors, their dielectric properties are more superior to those of aluminum and therefore they have higher capacitance which makes them suitable for filltering and decoupling obstructing applications.

(ii)non electrolytic: 

It is divided into several parts which are.

 1.Film capacitors.

they are also known as plastic capacitors because they are made of polystyrene,polycarbonate or Teflon as their dielectric material,thus they have big size and lower capacitance.

They are used in AC circuit because they don't have polarity. This types of capacitors are usually used in high radio frequency generation or reception, their working voltage range from few volts to 1400v and their metal plates are usually made from aluminum or zinc.

2.ceramic capacitors or disc capacitors.

they are inexpensive to manufacture, they are made by coating two sides of a small porcelain or ceramic disc with silver and are then stacked together to make a capacitor. 

They can be made with high and low capacitance by changing the size of the ceramic and it tickness.

They are used in high voltage circuit like a thousand volts and usually used the RF and audio systems. 

      Variable capacitor

Their capacitance can be varied mechanically and they are mostly used to tune or match frequency in LC circuits and also to adjust the radio for impedance matching in antenna tuner devices. 

       symbol of vairable capacitors.

     

Applications of capacitors.

1.used in making tank circuit in wireless power transmission.

2.used to reduce Sparks in vehicles induction heater coil.

3.for regulating flunctating current

4.to electronically tune frequency in radio cuircuits

5.used to analyze and fillter audio signals.

     How to calculate capacitor capacitance value and polarity.

1.electrolytic capacitors:

To check the polarity the black stripe side indicates the negative polarity,while the other side refers to positive polarity as shown below.

           negative polarity

                 positive polarity

2.cermic capacitor.

The figure on the capacitor indicates the capacitance value in Pico Farads.E.g 10=  10PF. And also If the third number is zero, then the value is in P e.g. 190= 190PF, for a 3 digit number, the third number represents the number of zeros after the second digit For example,  109= 10^9 PF.

Summary.

So far there are four of types of capacitors namely;

1.electrolytic

2.film

3.ceramic and lastly

4.vairable capacitor.

 

And also electrolytic capacitors are divided into tantalium and aluminum capacitors.

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