Symbols and Functions of Capacitors and Their Types

Capacitor symbols and functions and their types – Capacitors or also called Condensers (Condensators) are Passive Electronic Component that can store electrical charges in a while with their capacitance unit is Farad. The capacitor unit is named after its inventor Michael Faraday (1791 ~ 1867) who came from England. However, Farad is a very large unit, therefore in general capacitors used in electronics equipment are farad units that are reduced to pikofarad, NanoFarad and MicroFarad.

 

The conversion of Farad Units is as follows:

1 Farad = 1.000.000µF (micro Farad)
1µF = 1.000nF (nano Farad)
1µF = 1.000.000pF (piko Farad)
1nF = 1.000pF (piko Farad)

Capacitor is an Electronic Component consisting of 2 conductor plates that are generally made of metal and an insulator as a separator. In Electronic Circuits, capacitors are abbreviated with the letter “C”.

Types of Capacitors

Based on the insulator material and its value, capacitors can be divided into 2 types, namely fixed value capacitors and variable capacitors. The following is a brief explanation for each type of capacitor:

A. FIXED CAPACITOR

A Fixed Value Capacitor is a capacitor whose value is constant or unchanged. The following are the types of capacitors whose value is fixed:

1. Ceramic Capasitor (Ceramic Capasitor)

Ceramic Capacitors are capacitors whose insulators are made of ceramics and are thin or rectangular. Ceramic capacitors have no direction or polarity, so they can be mounted back and forth in electronic circuits. In general, ceramic capacitor values range from 1pf to 0.01μF.

Chip-shaped capacitors (Capasitor Chips) are generally made of ceramic materials that are packaged very small to meet the needs of electronic equipment designed to be smaller and can be installed by high-speed SMT Production Machine (Surface Mount Technology).

2. Polyester Capacitor

Polyester capacitor is a capacitor whose insulator is made of Polyester with a rectangular shape. Polyester capacitors can be mounted upside down in electronic circuits (lacking polarity of direction)

3. Paper Capacitor

Paper capacitors are capacitors whose insulators are made of paper and in general the value of paper capacitors ranges from 300pf to 4μF. Paper capacitors do not have directional polarity or can be mounted back and forth in electronic circuits.

4. Mika Capacitor (Mica Capacitor)

Mica capacitors are capacitors whose insulator material is made of mica material. Mika capacitor values generally range from 50pF to 0.02μF. Mika capacitors can also be mounted back and forth because they lack directional polarity.

5. Electrolyte Capacitor

An electrolyte capacitor is a capacitor whose insulator material is made of electrolytes and is tube/cylinder. Electrolyte capacitors or abbreviated as ELCO is often used in electronic circuits that require high capacitance. This electrolytic capacitor that has a Polarity of Positive (-) and Negative (-) directions uses aluminum as a wrapper and at the same time as its Negative terminal. In general, the value of electrolyte capacitors ranges from 0.47μF to thousands of microfarads (μF). Usually in the body of the Electrolyte Capacitor (ELCO) will be listed the Capacitance Value, Voltage (Voltage), and Negative Terminal. Things to note, Electrolyte Capacitors can explode if the polarity (direction) of installation is reversed and exceeds the limit of voltage.

6. Kapasitor Tantalum

Tantalum capacitors also have Positive (+) and Negative (-) directional polarities as well as electrolyte capacitors and their insulator materials are also derived from electrolytes. Called Tantalum Capacitor because this type of capacitor uses Tantalum Metal material as its Anode Terminal (+). Tantalum capacitors can operate at higher temperatures compared to other types of electrolyte capacitors and also have large sizes but can be packaged in smaller and smaller sizes. Therefore, Tantalum Capacitor is a type of capacitor that is expensive. It is generally used in small electronic equipment such as mobile phones and laptops.

Read also Definition of  IC (Integrated Circuit) and Its Applications

B. VARIABLE CAPACITOR

Variable Capacitors are Capacitors whose Capacitance values can be set or variable. Physically, this variable capacitor consists of two types, namely:

1. VARCO (Variable Condensator)

VARCO (Variable Condensator) is made of Metal of a larger size and is generally used to select Frequency Waves on Radio Circuits (combined with Spul Antenna and Spul Oscillator). VARCO Capacitance values range from 100pF to 500pF

2. Trimmer

Trimmer is a type of Variable Capacitor that has a smaller shape so it requires a screwdriver-like tool to be able to rotate its regulatory shaft. Trimmer consists of 2 metal plates separated by a sheet of Mica and there is also a Screw that regulates the distance of the two metal plates so that the capacitance value becomes changed. Trimmer in Electronic Circuit serves to compress the selection of Frequency waves (Fine Tune). Trimmer Capacitance value is only a maximum of up to 100pF.

 

Capacitor Function in Electronic Circuit

In Electronics Equipment, Capacitors are one of the most commonly used types of Electronic Components. This is because capacitors have so many functions that almost every electronic circuit requires them.

Below are some of the functions of capacitors in electronic devices:

• As a store of current or electrical voltage
• As a conductor who can skip ac current (Alternating Current)
• As an Insulator that inhibits DC (Direct Current) current
• As a Filter in a Power Supply Circuit
• As a Clutch
• As a Frequency Generator in a Series of Oscillators
• As a Phase Shifter
• As a Frequency Wave Selector (Variable Capacitor combined with Spul Antenna and Oscillator)

To find out How to Read Capacitor Values and also how to measure/test Capacitors, please read them in the article: How to Read and Calculate Capacitor Code Values and How to Measure Capacitors (Condensers).