Introduction to Electronics

 

The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices.

Having started with the atom will help us better understand electricity. Atoms comprise all matter. Atoms are the building blocks of the universe. The atom's nucleus, which is made up of protons with a positive charge and neutrons with no charge, is located in the centre of the atom. Additionally, the nucleus is surrounded by negatively charged electrons. The protons and neutrons are located at the centre of the atom, and the electrons continuously move around the nucleus.  The electrons in the nucleus can move almost as quickly as light, and they are significantly lighter than protons.

In shell-like, circular orbits, electrons circulate around the nucleus. There is a maximum number of electrons that each shell can hold. From the inside out, the shells are packed with electrons. The reactivity of the atom or its tendency to establish chemical interactions with other atoms depends on the number of electrons in its outermost shell. The atom is most stable and least reactive when that shell is full. The electrons located in the outer shell, also known as the valence shell, are referred to as valance electrons. Some substances in this shell have electrons that aren't tightly bound, allowing them to move freely between atoms. The term "free electrons" refers to these moving electrons. The ease of electron movement varies based on the material.

In general, atoms have a neutral charge, which indicates that they have an equal number of protons and electrons. They are electrically neutral, meaning their net electric charge is zero. This is referred to as the atom's ground state and is its lowest possible energy level. By making the atom gain or lose electrons, we can alter the charge of the atom. An atom gets negatively charged when it gains electrons and positively charged when it loses electrons. A positive or negative ion refers to a charged atom.

The unit of charge is the Coulomb, and the charge is symbolised by the letter "q". Since objects can have a positive or negative charge, "q" can have either a positive or negative value.

An elementary charge, represented by a lowercase "e," is the charge carried by a single electron or proton. The charges of electrons are -e, while protons are +e.

Current

Electric current is the flow rate of charge.

The flow of electric charge over a wire over time is known as an electric current. The symbol for electric current is I.

I  - Electric current

ΔQ - charge through the cross-section of a wire

Δt - change in time

C  - Coulomb

s  - Second

A  - unit for electric current

How do we measure current?

We can use an ammeter to measure current in any part of the circuit. It provides a reading in amperes. The current in the wires will be the same as the current in the ammeter if the ammeter is connected to the circuit in series, preventing branching.

Electricity comes in two forms: direct (DC) and alternating (AC). Electrons move in just one direction in direct current. DC is generated by batteries. Electrons flow in both directions in alternating currents. AC electric current is generated by power plants. BrightRidge provides you with alternating current (AC) electricity for your house. Alternating current is a technique in which the positive and negative poles are alternately switched regularly, changing the direction in which electricity flows.

DC

Advantages

• No circuit advance or delay
• Reactive power is not produced.
• Can store electricity

Disadvantage

• Current interruption is difficult
• Voltage conversion is difficult
• Strong electrolytic effect

AC

Advantages

• Less power is lost during high-voltage transmission.
• Easy to transform
• While the power is on, it is simple to turn it off
• Negative and positive voltage are not a concern.

Disadvantages

• Requires a higher voltage than the target voltage
• Affected by coils and capacitors
• Not suitable for ultra-long-distance transmission

How can I increase the current?

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance. Accordingly, increasing the voltage will increase the current, while increasing the resistance will decrease the current.

Two or more batteries are connected in parallel to improve the amp-hour capacity of a battery. While the amp-hour power will increase with a parallel battery connection, the battery voltage will stay constant.

Voltage

Voltage is the pressure from the power source of an electrical circuit that forces charged electrons through a conducting loop, allowing them to perform work.

In a sense, voltage = pressure and is measured in volts (V). Early on, the voltage was referred to as electromotive force (emf).

"potential difference" and "voltage" are frequently used interchangeably. The potential energy difference between two points in a circuit might be a better way to define the potential difference. How much potential energy there is to move electrons from one specific place to another depends on the differential (measured in volts). The amount indicates the maximum amount of work that could be done through the circuit.

How do we measure voltage?

Voltage is measured in volts(V). A voltmeter is used to measure the voltage across a circuit component. The component and the voltmeter need to be connected in parallel.