Topic: What is electronics?
Electronics is a technology that deals with the control of electric energy. It is everywhere around us, from computers to microwaves to the electronic fuel pumps in most cars. In this article you will learn about some of its basics and history. More about electronics on nerdytechy.com blog.
Early Electronics
The last half of the 19th century saw a revolution in physics, as it was discovered that many everyday phenomena—such as heat, light, and electricity—are part of the same fundamental interaction between matter and electromagnetic waves. This led to the birth of electronics as a field focused on studying how these interactions could be applied practically for humanity's benefit. The first practical application was invented by Thomas Edison, who demonstrated an automated telegraph system that sent messages over wires as electrical signals instead of pulses of light.
Electronics Components
It wasn't long before people started using these discoveries to make useful devices. The most basic electronic components are resistors, capacitors, and diodes.
Resistors are parts that restrict or resist the flow of an electric current in a circuit. Their resistance is measured in ohms with traditional units, but can also be expressed by the more modern SI units of kilo-ohms (kΩ) or mega-ohms (MΩ). The important thing to remember is that higher resistance = less current flow for any given voltage.
Capacitance is the ability of certain materials to store an electric charge. A capacitor consists of two metal plates separated by insulation so they don't touch. Because opposite charges attract and like charges repel, the electrons will move from one plate to the other when a voltage is applied. If you have ever felt your hair stand on end after combing it in winter, that's electric capacitance at work!
A diode allows current to flow one way but not the other. It consists of a piece of semiconductor material with a small amount of electrical charge already built in. Applying a voltage to this material will cause some of these charges to move around, thus reversing their polarity. This creates an electronic barrier that prevents current from flowing back through the diode in the reverse direction. In this sense, diodes are kind of like rechargeable batteries: if you apply more electricity than they're rated for, they'll burn out.