How capacitor uses and function in electronics

2024-08-17

Electronic gadgets have become an integral part of our lives. They have made our lives more comfortable and convenient. From aviation to medical and healthcare industries, electronic gadgets have a wide range of applications in the modern world. In factor, the electronics revolution and the computer revolution go hand in hand.

Most gadgets have tiny electronic circuits that can control machines and process information. Simply put, electronic circuits are the lifelines of various electrical appliances. This guide explains in detail about common electronic components used in electronic circuits and how they work.

Electronic Circuit Overview

An electronic circuit is a structure that directs and controls electric current to perform various functions including signal amplification, computation, and data transfer. It comprises several different components such as resistors, transistors, capacitors, inductors, and diodes. Conductive wires or traces are used to connect the components to each other. However, a circuit is complete only if it starts and ends at the same point, forming a loop.

The Elements of an Electronic Circuit

The complexity and the number of components in an electronic circuit may change depending on its application. However, the simplest circuit consists of three elements, including a conducting path, a voltage source, and a load.

Element 1: Conducting Path

The electric current flows through the conducting path. Though copper wires are used in simple circuits, they are rapidly being replaced by conductive traces. Conductive traces are nothing but copper sheets laminated onto a non-conductive substrate. They are often used in small and complex circuits such as Printed Circuit Boards (PCB). 

Element 2: Voltage Source

The primary function of a circuit is to allow electric current to pass through it safely. So, the first key element is the voltage source. It is a two-terminal device such as a battery, generators or power systems that provide a potential difference (voltage) between two points in the circuit so that current can flow through it.

Element 3: Load

A load is an element in the circuit that consumes power to perform a particular function. A light bulb is the simplest load. Complex circuits, however, have different loads such as resistors, capacitors, transistors, and transistors.

Electronic Circuit factors

1.factor 1: Open Circuit

As mentioned before, a circuit must always form a loop to allow the current to flow through it. However, when it comes to an open circuit, the current can’t flow as one or more components are disconnected either intentionally (by using a switch) or accidentally (broken parts). In other words, any circuit that does not form a loop is an open circuit.

2.factor 2: Closed Circuit

A closed circuit is one that forms a loop without any interruptions. Thus, it is the exact opposite of an open circuit. However, a complete circuit that doesn’t perform any function is still a closed circuit. For example, a circuit connected to a dead battery may not perform any work, but it is still a closed circuit. 

3.factor 3: Short Circuit

In the case of short-circuit, a low-resistance connection forms between two points in an electric circuit. As a result, the current tends to flow through this newly formed connection rather than along the intended path. For example, if there is a direct connection between the battery’s negative and positive terminal, the current will flow through it rather than passing through the circuit.

However, short circuits usually lead to serious accidents as the current can flow at dangerously high levels. Hence, a short circuit can damage electronic equipment, cause batteries to explode, and even start a fire in commercial and residential buildings.

4.factor 4: Printed Circuit Boards (PCBs)

Most electronic appliances require complex electronic circuits. That’s why designers have to arrange tiny electronic components on a circuit board. It comprises a plastic board with connecting copper tracks on one side and lots of holes to affix the components. When the layout of a circuit board is printed chemically onto a plastic board, it is called a printed circuit board or PCB.

Electronic Components

Thanks to modern technology, electronic circuit building process has been completely automated, especially for building ICs and PCBs. The number and arrangement of components in a circuit may vary depending on its complexity. However, it is built using a small number of standard components.

The following components are used to construct electronic circuits.

Component 1: Capacitor

Capacitors are widely used to build different types of electronic circuits. A capacitor is a passive two-terminal electrical component that can store energy in an electric field electrostatically. In simple terms, it works as a small rechargeable battery that stores electricity. However, unlike a battery, it can charge and discharge in the split of a second.

A. Composition

Capacitors come in all shapes and sizes, but they usually have the same primary components. There are two electrical conductors or plates separated by a dielectric or insulator stacked between them. Plates are composed of conducting material such as thin films of metal or aluminum foil. A dielectric, on the other hand, is a non-conducting material such as glass, ceramic, plastic film, air, paper, or mica. You can insert the two electrical connections protruding from the plates to fix the capacitor in a circuit.

B. How Does It Work?

When you apply a voltage over the two plates or connect them to a source, an electric field develops across the insulator, causing one plate to accumulate positive charge while negative charge gets collected on the other. The capacitor continues to hold its charge even if you disconnect it from the source. The moment you connect it to a load, the stored energy will flow from the capacitor to the load.

Capacitance is the amount of energy stored in a capacitor. The higher the capacitance, the more energy it can store. You can increase the capacitance by moving the plates closer to each other or increasing their size. Alternatively, you can also enhance the insulation qualities to increase the capacitance.

 C. Function and Significance

Though capacitors look like batteries, they can perform different types of functions in a circuit such as blocking direct current while allowing alternating current to pass or smooth the output from a power supply. They are also used in electric power transmission systems to stabilize voltage and power flow. One of the most significant functions of a capacitor in the AC systems is power factoror correction, without which you can’t provide sufficient amount of starting torque to single phase motors.

Filters Capacitor Applications

If you are using a microcontroller in a circuit to run a specific program, you don’t want its voltage to drop as that will reset the controller. That’s why designers use a capacitor. It can supply the microcontroller with the necessary power for a split second to avoid a restart. In other words, it filters out the noise on the power line and stabilizes the power supply.

Hold-Up Capacitor Applications

Unlike a battery, a capacitor releases its charge rapidly. That’s why it is used to provide power to a circuit for a short while. Your camera batteries charge the capacitor attached to the flash gun. When you take a flash photograph, the capacitor releases its charge in a split second to generate a flash of light.

Timer Capacitor Applications

In a resonant or time-dependent circuit, capacitors are used along with a resistor or inductor as a timing element. The time required to charge and discharge a capacitor determines the operation of the circuit.

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