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An ion is any atom that bears a positive or negative electrical charge. Positively charged ions are called cations; negatively charged ions, anions. The imbalance between quantities of electrons and protons gives rise to electron movement both within and between atoms. Electronics is, therefore, about the flowing motion produced by an electric charge.
A duct is pretty much any channel such as a tube, canal, pipe, or conduit by which a fluid such as water or gas, or a particle may be conveyed. The act of conveying or channeling by means of a duct or ducts gives rise to certain essential terms that we use to understand and make use of electricity. In this treatment we will consider the process by which an electrical charge is inducted andconducted.
The most basic definition of induction highlights the act of inducing, bringing about, or causing someone or something to be influenced in some way. Much of what we know, and most of our suppositions about electricity and how it behaves, is a product of inductive reasoning. Such reasoning aims at developing a theory while deductive reasoning aims at testing an existing theory. To deduce means to trace the course of something, so deduction is also an essential skill used in understanding circuitry.
Our objective, with respect to understanding electrical induction and conduction, is to trace the course of electrons as they enter into and flow through a circuit. Induction occurs when a changing magnetic field results in a potential difference, commonly known as voltage, in a conductor. This is known as electromagnetic induction. The current or voltage is called either an induced current or an induced voltage. The potential, termed voltage, is often understood by analogy to the pressure at the head end of a pipe connected to a water tower.
A stationary magnetic field will have no effect on a wire or current-loop. A moving or changing magnetic field, in proximity to the conductor, will generate an electric current. An electrical conductor is usually a substance in which electrical charge carriers, usually electrons, move easily from atom to atom with the application of voltage. Conductivity, in general, is the capacity to convey something, such as electricity or heat. In metallic conductors, such as copper or aluminum, the movable charged particles are electrons, though in other cases they can be ions or some other positively charged species.
Just as a human conductor or leader of a musical group communicates, by motions of hands or a baton, we can think of conducting as a way of controlling as well as facilitating something akin to an orchestral score. As it is with musicians, engineers can conduct or instruct electrons to move in accordance with their own preferences. They can apply such skills for controlling intensity, frequency, and changes in tempo. There’s more than one way to design even the simplest of circuits. For example, a switch could be located between the positive terminal of the battery and a lamp, or between the negative terminal of the battery and the lamp. The choice may be influenced by the physical layout, the type of switch used, the location of other components within the circuit, or simply a coin toss.
While there sometimes are occasions where such choices don’t really matter, there are also precision applications where, as with a switch, such choices can make or break the ultimate success of your project. For example, in a high speed computer, the physical location of a component within a circuit can affect timing in ways that may or may not keep things in sync. It can subject a sensitive component to magnetic fields resulting in unintended induction of emissions from elsewhere that interfere with optimal performance. It can also cause components to overheat in ways that shorten their service life.
Michael Faraday conducted a series of tests on a wire coil in 1831. He is believed to be the first scientist and mathematician to document the relevant findings. Electromagnetic Induction is the governing principle that is used to explain how electrical generators, alternators, microphones, electric guitars, speakers, and transformers operate. The generator was an innovative industrial concept. By changing mechanical energy into electrical energy, the generator relied upon the basic principle of electromagnetic induction, that of passing an electrical conductor through a magnetic field. The motor changes electrical energy into mechanical energy. The voice coil in a microphone consists of a wire coil that moves over a permanent magnet. It is a good example of a generator, while using the same component within a speaker causes it to behave like a motor.
Understanding circuits, how they work, and the optimal use of components is at the heart of electronics. Once the reciprocal relationship between electricity and magnetism was thoroughly understood, the practical applications were virtually limitless.
The radio was another one of the early inventions that applied the science of electromagnetic waves. More contemporary developments include induction heating and induction brazing, a process used in metal fabrication where different metals are soldered or welded together to form one workable material.