Electrolytic Capacitor Symbol, Working, Types, Construction & Uses

Introduction of Electrolytic Capacitor Symbol

• These types of capacitors are used in electronic circuits due to their high capacitance value. They are created with two conductive plates having electrolytes between the plates.
• The electrolyte is created with conductive material that is used for the increment of capacitance per unit volume of the capacitor. .

What is an Electrolytic Capacitor?

• In this category of capacitors, there is an electrolyte used as one plate of the capacitor. That electrolyte can be liquid, gel, or solid material.
• The electrolyte is mostly created with aluminum oxide film or titanium oxide film that is made through the ionization process.
• The oxides film work as an insulator between plates and capacitors

Electrolytic Capacitor Symbol

• The symbol of an electrolyte capacitor is made with two lines denoting plates of capacitors with a curved line joining them. The curved line denotes electrolyte-separated plates.
• The longer line denotes a positive plate but the shorter line denotes a negative plate. The symbol also consists of the capacitance value and voltage rating of the capacitor.
• The polarity of the electrolytic capacitor should be noted when using symbols in circuits. The positive plate should be attached to the positive voltage in the circuit and the negative plate should be connected to a negative voltage

Polarized Capacitor Symbol

• The symbol of the polarized capacitor is created with two lines that represent plates of the capacitor having curved lines connecting them. The curved line denotes dielectric material which separated plates.
• One of the lines is larger and has plus sign that indicates a positive terminal. The smaller line has a negative sign that shows a negative point.
• The polarity of polarized capacitors should be noted during circuits.

Working Principle of Electrolytic Capacitors

• The working of the electrolytic capacitors is like the other capacitors. If voltage is applied to the plates of capacitors charge is stored on capacitor plates. the capacitance of the capacitor is in direct relation to the surface area of plates and the distance between plates.
• In the case of electrolyte capacitors distance between plates is smaller that causes a larger capacitance per unit volume

Types of Electrolytic Capacitors

• There are three main types of electrolyte  capacitors listed here
• aluminum electrolytic capacitors
• tantalum electrolytic capacitors
• niobium electrolytic capacitors

Aluminum Electrolytic Capacitor

• Aluminum electrolyte capacitors are a commonly used type of electrolyte capacitor.  It is created with two aluminum plates that are separated by electrolytes.
• The anode plate is created with pure aluminum and the cathode plate is created with aluminum coated having a layer of manganese dioxides
• The anodization process makes an insulating layer of aluminum oxides on an anode plate that work as dielectric capacitors

Tantalum Electrolytic Capacitor

• The tantalum electrolyte capacitor is smaller in size than aluminum electrolyte capacitors and comes with higher capacitance per unit volume. It is created with a tantalum metal plate and electrolyte. The tantalum plate has a coating of tantalum oxides that work as dielectric of the capacitor.

Niobium Electrolytic Capacitor

• The niobium electrolytic capacitor is small in size than the tantalum electrolyte capacitor that is created with a niobium metal plate and electrolyte.   The niobium has a coating of niobium oxides that work as a capacitor dielectric

Construction of Electrolytic Capacitors

• The construction of the aluminum electrolyte capacitor comes with the placement of an anode plate and cathode plate in close structure to each other and separated through the electrolyte.
• The anode plate is created with pure aluminum and the cathode plate is created with aluminum coated with a manganese dioxide layer.
• The anodization process makes an insulating layer of aluminum oxide on an anode plate that works as the dielectric of the capacitor. The aluminum layer is very thin that resulting in a large capacitance per unit volume

Tantalum Electrolytic Capacitor Construction

• The construction of this capacitor uses a tantalum metal plate and electrolytes confined close to each other. The tantalum plate is coated with tantalum oxide that works as a capacitor dielectric. The construction of tantalum electrolyte capacitor resulted in a small size structure than aluminum electrolyte but has a high capacitance per unit volume

Applications and Uses of Electrolytic Capacitors

• Electrolytic capacitors are mostly used in electronic circuits since has high capacitance values. Here main applications are explained

Audio amplifiers

• These capacitors are mostly used in audio amplifiers for smooth output voltage and to eliminate undesired noise from signals.

Power supplies

• They are also used in power supplies for storing and filtration of voltage

Radio-frequency circuits

• it also used in radio frequency circuits to block and filter undesired signals

Lighting applications

• it is also used in lights to store energy and voltage regulation

What is an Electrolyte Inside the Electrolytic Capacitor?

• The electrolyte in the electrolytic capacitor is a conductive liquid or gel which works as a capacitor electrode. The electrolyte is normally in a solution of salt like boric acid, ammonium borate or sodium borate that is created in a solvent like water or glycol.
• The electrolyte performed the two main functions in capacitors. The first one is it provides a conductive path among two electrodes permitting charge to flow in a capacitor. 2nd one is it makes a dielectric layer on an aluminum oxide surface, which permits the capacitor to get a high value of capacitance
• The electrolytes employed in capacitors can be polar or nonpolar. Polar electrolyte comes with positive and negative charges that allow making polarized capacitors that can only be connected in one direction.
• Non-polar electrolytes do not have positive or negative charges and are used to make non-polarized capacitors that can be connected in any direction

How to Read Capacitance Value?

• The capacitance of the capacitor is normally indicated through a series of numbers and letters printed on capacitors. Here we have discussed how to read capacitance value.

1. Identify the value in picofarads (pF): The first two digits of the capacitor denotes the value in picofarads. For example, the capacitor that has code”47″ comes with a value of capacitance  47 picofarads.
2. Determine the multiplier: The third digit on a capacitor is a multiplier. That is a power of 10 which indicates how many zeroes must e added in the value of picfarads For instance capacitor having code “473” has a multiperl three which means that the capacitance value must be a product with  1,000. So the capacitance value of capacitors is 47,000 pF or 47(uF)
3. Check the tolerance: Some capacitors also have a 4th digit that indicates tolerance or acceptable range error in capacitance value. For instance, a capacitor having code “473J” comes with a tolerance value of ±5%.

What are the Advantages and Disadvantages of Electrolytic Capacitors?

• Here are some advantages and disadvantages of electrolytic capacitors are explained.

Advantages	Disadvantages
It provides the High capacitance values	It comes with a limited voltage rating
It has a Small size	Its operating life is short than other capacitors
Low expensive	It makes poles or Polarization
High ripple current capability	Can explode if operated above rated voltage or temperature
It is best for low-frequency applications	It has a limited  temperature range
It has high-voltage applications	It not used for precision applications
It comes with different ranges of  capacitance values	It has Limited self-healing ability

Conclusion:

In conclusion, an electrolyte serves as one of the plates of a form of capacitor known as an electrolytic capacitor. They have high capacitance values, which are commonly employed in electrical circuits. tantalum electrolytic capacitors, Aluminum electrolytic capacitors,  and niobium electrolytic capacitors are the three different kinds of electrolytic capacitors. Each variety has a unique design as well as benefits and drawbacks. Numerous devices, including audio amplifiers, power supplies, radio-frequency circuits, and lighting fixtures, require electrolytic capacitors.

FAQs

1. Can electrolytic capacitors be used in AC circuits?

• Yes these capacitors can be used in AC circuits, but they need an accurate polarity connection

2. How do we know the correct polarity of an electrolytic capacitor?

• The negative side of the electrolyte capacitor has a stripe or negative sign

3. Can electrolytic capacitors be used in high-temperature conditions?

• These capacitors have a limited temperature range so if we use them in outer that range can be damaged

4. How can I extend the operating life of electrolytic capacitors?

• These capacitors can be stored at low temperatures to increase the operating life

5. Write the maximum capacitance value of an electrolytic capacitor.

• The maximum capacitance value depends on the type and size of the capacitor.