Understanding the basics of electronics can be a daunting task for some people, while others find it very easy to grasp current and voltage concepts. This guide will take you through each of the basic concepts of electronics one at a time, and make sure that you understand and get an insight into each of the topics without getting bored. So, let’s get started!
Before delving into the basic terminology, you must know what charges are. There are two types of charges; positive and negative. Like charges repel, while unlike charges attract. Every atom has positive and negative charges. Positive charges are inside the nucleus and are called protons, while negative charges, called electrons, are in orbits surrounding the nucleus.
These electrons either stay inside the orbits or move as free/mobile electrons, depending on the type of element they belong to. If you look at the periodic table, notice that the elements are divided into three categories; metals, semiconductors, and non-metals. Metallic elements have mobile electrons, which is why they are called conductors, while non-metals hold on to their electrons tightly—therefore making them poor conductors.
What is current, then? It is the rate of flow of charges, which means that if you count the number of charges passing through a point inside a wire, in one second, then you will get the amount of current flowing through it.
What is the direction of current flow in a circuit? The path in which electrons flow is referred to as electric current, while the conventional is in the opposite direction. You may say that it is the flow of positive charges. Within a circuit, the conventional current path is from the positive end of the battery to the negative end, as shown in the diagram below.
The difference in charge between two points is defined as voltage. To understand it better, consider the energy analogy. If a ball is present on top of a hill, it has a high amount of potential energy compared to what is left after it rolls down and reaches the bottom. Along the way, the ball loses power in exchange for some work done. Similarly, electrons experience a change in energy as they move through a circuit. The difference in their energy between two points is termed as voltage.
Ohm’s law relates voltage and current in a circuit. Here is what it states:
Where; V is the Voltage in Volts,
I is the current in Amperes, and
R is the resistance in Ohms.
We will look at resistors in detail in the next section. The circuit below demonstrates how voltage is measured between two points across a resistor.
Generally, power is defined as the rate of energy transfer. We all know that energy can not be destroyed, but it can be transformed from one form to another. For example, potential energy is converted into kinetic energy when a rock rolls down a hill; how fast this transfer takes place is another way to measure power.
In electronics, electrical energy is converted to other forms of energy, and vice versa. For example, when a battery supplies power, chemical energy converts into electrical energy. Similarly, a bulb lights up as a result of converting electricalContinue reading