website/_posts/2018-08-18-simplified-introduction-to-electronics-1.md

layout	title	date	author	categories	tags
post	[Simplified!] Introduction to Electronics I	2018-08-18 00:52:05 +0800	foo-dogsquared	electronics	programming-notes electronics simplified

Electricity, arguably the most important discovery of mankind. This incredibly amazing thing overwritten the humanity's way of living from manufacturing, transportation, utilities, infrastructure, agriculture, and computing which includes our common computers that can serve a variety of purposes such as calculating simple arithmetic to complex functions, play games, create digital art, and creating programs.

You get the idea, electricity pretty much integrates with everything now and it helped us a lot in a lot of ways. If you would think of an object that doesn't involve electricity, you would have a hard time thinking about that.

I mean coins is an object that doesn't involve electricity but how are the coins created in the first place? Machines which does use electricity.

How about the clothes? Surely, there are some clothes that are created by hand but then most of them are created from the machines in order to mass produce them. There's also the sewing machine which it does have a mechanical version of it but nowadays, it is mostly electrical now.

Let's dive right into the world of electronics where these things are usually at your crafting table.

HINT: You can skip some of them since electronics is really a practical subject on the beginner level but that doesn't necessarily mean that you can go and be comfortable in electronics without understanding them.

A new start on the world of electronics

OK. Now you want to make your feet wet into the waters of electronics. Usually, in order to get into electronics, you would need to have some components and tools. Otherwise, you would just go through the knowledge materials that you refer to as if it is just another storybook — to keep you entertained with all of the theoretical topics for a while and move on to the next one.

Entering the world of electronics can be sometimes a mess and will make your workspace looks like a garage that needs a yard sale so be prepared to be get your hands dirty and get your organizing skills on to your daily toolbelt. (Or you know, get a container suitable for the components and you won't have a big worry, probably.)

*Also, welcome to my chaotic workspace, everybody.*{: .caption}

Usually, with electronics, you would want to have some basic components like LEDs, resistors, capacitors, switches, integrated circuits, and transistors and some tools like a breadboard, wire splicer, tweezers, and your ol' handy-dandy paper and pen because we are not really going full-on engineering without some kind of planning and theoretical stuff, right?

I would recommend to research more about the electronic components afterwards but for now, let's take a very quick glance over each components for a very quick headstart:

• breadboard — mainly serves as prototyping tool for the circuit (we'll get to that later)
• light-emitting diodes — also known simply as LEDs; they are not only used for illumination but also serves as indicators for our devices
• resistors — control the electricity flow by reducing the voltage from the flow
• capacitors — store a bit of electricity
• switches — simply connect or disconnect the electricity flow
• transistors — they are simply switches that redirects electricity flow by the electrical signals
• integrated circuits — it refers to any circuit that is integrated into a chip or any viable small container

*Can you identify some parts at the end of the part two of this entry?*{: .caption}

With all of these said, it is usually recommended for a complete beginner to just buy an beginners' electronic kit since all of the materials needed to get started are already there. You would just have to practice to choose components yourself on the later part when you are more comfortable with the mechanics of each components and the tools.

Electricity

In order to start raring into building those DIY electronics stuff that you always see on different websites, you have to be familiar with the foundational concept(s) it is based upon which is electricity. It is the driving force of the devices you always interact with: personal computers, smartphones, remote control, lamps, doorbells, cars, and sub-infinitely more, as you can tell.

Electricity seems magical to an person who is not familiar with the inner workings of it. Let's start with a seemingly simple example, like the remote controller for your TV. It is mainly made up of buttons and when we press those buttons, stuff happens. Like if we press the button for increasing the volume, the audio output from the TV does increases. It all seems like a mysterious magical box/rectangle thing with the buttons that can indeed do stuff in your TV.

Or if you have fiddled something like fixing a light bulb, for example.

We connect the light bulb's terminal with two connecting wires, then connect the other end of the two wires with a battery and place it appropriate to the charges to the battery, and voila, the light bulb lit up. How does that even work?

As it turns out, the force that makes your electronic devices work as they should be is made up of atoms — very small particles that can only be seen through a special kind of microscope. These atoms, as you probably encountered before on school, the basic building blocks of everything we can see in the universe and are made up of three smaller particles: the neutron, the proton, and the electron. The latter two of which have electrical charges: proton usually has a positive charge, and electron usually has a negative charge. In most circumstances, the protons and the neutrons make up the nucleus and the electrons just fly outside of the nucleus orbitting around it. So yeah, we can imagine it as if the atom is like the solar system: the nucleus is the sun and the electrons are the planets orbitting around it.

The number of protons and electrons make up the composition and define what type of atom it is. For instance, if we would want to have a hydrogen atom, we would just have an atom that is mainly composed of one proton and one electron. Substances containing only one type of atom are often referred to as an element as in the elements that can be found in the periodic table.

Objects (i.e. a chair, a speaker, or a USB cable) and materials (i.e. leather, rubber, or plastic) are a larger bunch altogether that these are usually made from several elements mixed together into what they call a compound. These compounds and elements are what makes up the objects and materials. Usually, these composition also what dictates how components of the atoms move and interact.

But really, what we are specifically looking for in here is the electrons. They are the culprit in making electronic things do stuff.

Electric charges

Each of these particles, as you know from basic physics, have what they call an electric charge which describes how they would interact with another particle. Protons and electrons are both particles that are electrically charged, they just have different type of charges. As previously mentioned, protons usually have a positive charge while electrons have a negative charge. This would dictate how particles would interact with each other: positively-charged particles would attract to negatively-charged particles and repel fellow positively-charged particles. The same behaviour describes how negatively-charged particles do except the type of particle in each type of interaction is reversed. This behavior is very similar to the how magnet poles work. Magnets with two poles would have its both end attracted to its opposite pole and repelled to the same pole. This is what essentially the Law of Attraction is.

Like charges repel, opposite charges attract.

There are some objects whose the atoms’ electrons are freely flying around the atom shell, labelling them to be as free electrons. These extra electrons are now moving freely wherever they want as long as they hang around the atom unless they are being interacted with an outside force.

The number of free electrons around an object is used to describe the charge of the object. Having too many electrons can be said that the object is negatively charged and having a few missing electrons renders the object positively charged.

Conductors such as metals are defined as letting these extra electrons to flow around since the materials are loosely bound, so much loose that the free electrons are jumping from atom to atom. Insulators such as wood, leather and plastic, on the other hand, are so tightly packed that the electrons cannot move around. They just sit there with the electrons and the protons stay in one place.

Another thing with the electric charge is that it is the underlying most basic quantity to be used on electronic systems. We can express it on mathematical terms.

(For the sake of the scope of this post, I'm going to keep it at a minimal.)

Take note that a coulomb is used to describe the magnitude carried by \(6.241 * (10^{18})\) electrons in a second.

Electric charge is using coulomb (C) (pronounced as "col-lume") as the unit of measurement. As you may have encountered on your high school physics, there is a constant called the elementary charge in which it describes the charge of a proton. You may not have heard the term but you have likely encountered that \(e^+\) is equal to \(1.602 * (10^{-19}) C\). The charge of a single electron can be denoted as \(e^-\) and it is equivalent to the charge of proton, albeit negative.

With this equating the balance between them, an object can stay electrically neutral but even if the object has a charge, the net charge is still down to zero. We cannot really add nor subtract the amount charge on the particle without affecting the other. This is what the law of conservation of change is all about:

Energy can neither be created nor destroyed, only transferred.

Therefore, charge can neither be created nor destroyed, only transferred.

While we're on the topic of electric charges, let's go and jump through some of the very important concepts when it comes to electronics like:

• electric flow
• current
• voltage
• resistance

The fundamental concepts of electricity

The previously mentioned four concepts pretty much sums up of what you would always encounter when dwelling further into electronics.

Electric flow

This refers to the movement of electrons around a circuit.

As of tradition (or I just can't think of another analogy), let's imagine the electrical circuit as a water pipe system. You most likely know the appearance and components of an electric circuit even if you haven't interacted with it that much. In a simple electrical circuit like a LED circuit, there is:

• wire as the water pipe
• the battery as the water pump
• the resistor as the narrower water pipe thing
• the LED as the faucet, releasing energy as heat

Take note of this analogy as we will continuously add comparisons as we go on further into the concepts.

*Water pipe analogy (I have to put a picture there)*{: .caption}

How does an electric flow occurs?

Starting from the big picture. We know that objects are made from atoms. We know that atoms are composed of electrons, protons, and neutrons. We certainly know that electrons hang around the orbit of the protons and neutrons forming a nuclei at the center. We know that there are certainly some free electrons that are hanging around outside of that atom shell. We know, for certain, that electrons repel from each other and attracts to a proton.

Let's think about that last statement and elaborate with an example. Let's think of a simple chain of atoms with some electrons orbitting around them.

*A chain of atoms*{: .caption}

Let's imagine there's an electron is moving for whatever reason.

*Then a chain reaction will occur*{: .caption}

Since electrons repel from each other, whenever there's a movement of an electron, surely there will be other electrons that will be affected from it. Even though this is not true for most of the time, we can say that we can move one electron without affecting the other.

From the example above, let's scale things up from a chain of atoms to an assembly to atoms, say from a conductor.

*Simplified representation of the atom structure inside of a conductor*{: .caption}

Since conductors have an arrangement that is loosely bound only held by protons that stay in one place preserving the structure of the metal, electrons can freely move jumping from one atom to another. From that point, we can really see the chaotic and numerous movements that will occur when one electron moves.

Now let's imagine that conductor is now a part of an electric circuit which unlike [that circuit], this is made up of materials that can let electrons flow, AKA conductors. If there is any force that made electrons move, try to imagine what will happen now that it is in a complete circuit. Since we are now essentially connecting conductors to form a path for the electrons, the electrons have more space to explore and in case there is a force that made the electrons move, a chain reaction will occur between electrons. An electron will push away an electron and that electron will push other electrons which in turn will push other electrons in their way as they're being repelled.

Within a circuit, they're basically going on a circle. An endless loop of repelling electrons going on circles until the forces that is making them move in the first place stops interferring.

That is how an electric flow occurs in its basic form.

In the water pipe system analogy, we can simply say that the electric flow is simply when the water pump starts to work to create the force that makes the water go through the pipes.

Current

The second item on the list is the current which, simply describes the flow of the electricity by measuring the number of charge carriers (usually electrons) passing through a single point in any given time.

Continuing the water pipe analogy, the current is the amount of water flowing through at a certain point. In fact, the word current is borrowed from a unit in hydraulics that describes the amount of water flowing through at a certain point. The more you know. 🌈⭐

Current is usually uses the SI unit, amperes (A) or amps, for short. An ampere is said to be about \(6.241 * (10^{18})\) flowing electrons per second. You don't need to memorize that number, just know that an ampere measures a lot of electrons is flowing. As we start out from our journey of learning electronics from the very beginning, we often work with electronic system that utilizes a lot fewer of these amperes, most of them does not even go up to 1 unit of ampere. Devices such as a mouse, antenna, and those small-scale DIY electronic projects you see on the internet uses amperes ranging from microamps (μA) to miliamps (mA) when compared to the common appliances like the fridges, vacuum cleaner and a television wherein each appliances usually uses more than 1A.

Speaking of amperes, the unit Coulomb (C) is related to it in a way that it describes the magnitude of a certain number.

Remember what 1C represents and how many electrons in an ampere? Both of them measures around \(6.241 * (10^{18})\) electrons. So we can say that an ampere is equal to one coulomb of charge per second.

 1 A = \frac{1 C}{1 s}

Voltage

The third variable on the list is the voltage. We can simply say that voltage is the force that pushes around the electron so that the electric flow can start but there's a slight confusion around the term. The technical term for the force that pushes around the electron is the electromotive force (EMF) but we can still use the term "voltage" to describe the necessary force to make electron flow happens.

To make things easier to understand between this, the force that makes free electrons flow is what electromotive force is and to make the force that makes the free electrons flow is what voltage does.

Now let's talk about what voltage is.

As stated from Afrotechmod's video on voltage, "Voltage is a difference in electrical potential energy per unit of charge between two points."

Let's break the definition down by discussing the definition of the keywords in the definition.

As you have encountered on elementary physics, energy is the ability to do work. Work simply means any action whether it is moving of things, heating of things, or transforming of energy into something else.

Potential energy is the potential to do work. Like an object in an elevated height, having the potential to do work by the gravity that constantly pulls down everything only blocked by the ground it standing on. Another example is with an arrow ready to be fired from the bow, the arrow has a potential energy that is being held by the bowstring. The moment that bowstring is released, the arrow will propel, actually utilizing and releasing energy and interaction with the objects in its way.

How about electrical potential energy? Simply put, it is electrical energy with the potential to do work. The battery, when left alone doing nothing, has an electrical potential energy. Same with the conductors whose free electrons are just waiting to get out and move on to different parts of the circuit. Or any components waiting for their work, generally.

Next is the per unit of charge part of the definition. That's easy as we've already discussed that before: coulombs. A coulomb is a unit of charge. What about for energy? Generally, when talking about energy, it uses what they call a joule. Therefore, one of the ways to describe voltage in units is \(V = \frac{J}{C}\). To put it into words: for each coulomb of charge flowing through the circuit, a certain amount of joules of energy is released.

OK. Now's let take a look at the definition again:

Voltage is a difference in electrical potential energy per unit of charge between two points.

A difference of electrical potential energy between two points. Generally, in order to have a difference, one has to be higher and the measure that is being based the number of electrons. One has to be positively charged (aka lack of free electrons) and the other to be negatively charged (aka has too many electrons). Yeah, it is the reason why batteries have a negative and positive terminals.

In the cases of batteries, we can say that the voltage is the difference of potential energy between those two terminals.

In case you're still holding to the water pipe analogy, voltage is basically pressure, the force that pushes water around the pipe circuit. Also, you may see voltage is being called into its other names such as potential difference, tension, and even pressure.

Resistance

Last but not the least, the resistance which in its most essence the measurement of getting against the electric flow. This is probably one of the hardest to configure, at least in my personal experiences. As the lack of this ingredient will cause your component to blow up. However, this does emphasize the importance of applying resistance into our circuit.

Resistance simply measures the strength of opposition of an object / electronic component from the current. In other words, resistance is the ability to go against the flow.

Resistance uses the SI unit, ohms, represented by the Greek uppercase letter omega (Ω).

When the resistance value is more than the current, it defeats the purpose of the resistance as it is made to reduce the amount of current that's flowing into. Think about it, even if we have never tinkered too much with an electric circuit, we know when we've put too much resistance on the circuit, the circuit will not work as if no current is flowing at all or it will have a very weak electron flow. For exmaple, if we have a simple LED circuit with a resistor whose value is too high, the LED will have a dimmer light compared when applied with a resistor with lower resistance (don't directly connect the LED with the batter alone, though, it will burn out).

If we were to represent the resistance in the water pipe system analogy, it will be a narrower pipe. There will be a decrease on the amount of water that will flow through it.

Ohm's Law

Now that we have discussed the three main variables which are current, voltage, and resistance, we can now go into details of how they relate to each other.

Enter Georg Ohm, who is the first to be recognized to say that there is a relationship between the three. He noticed that the current is directly proportional to the voltage, coupled with the concept of resistance. Ever since, scientists agreed and decided to make it as a law... or something. And here we are, discussing about Ohm's Law.

As previously mentioned two sentences ago, Ohm's Law states that the current is directly proportional to the voltage.

However, there is another variable included in the circuit and that is the resistance. Knowing how resistance would work in a circuit, you can conclude the mathematical relationship between them:

 I = \frac{V}{R} 

Knowing that it is a algebraic representation of their relationship, you can derive the formulas on how to get the remaining variables.

For voltage:

 V = I * R 

For resistance:

 R = \frac{V}{I} 

I find it much easier if you would take the formula for voltage in mind, practically speaking, since it is much easier to derive formulas from that point compared to others.

As we go on to the practical side of electronics, we will see how to use in practical application but for now, let's get up and running with an example:

Say that we have a 9V battery with an LED that tolerates up to 20mA. How much resistance are we going to apply to the circuit?

Well, the unknown value is resistance so let's use the formula, \(R = \frac{V}{I}\).

We just integrate our given values into the formula, then that's it. The given values are our voltage (\(V\)) which is 9 and for the current (\(I\)) which is 20mA. Since the standard unit for the current is an amp (A), we would convert the values into its appropriate units. In this case, we simply convert 20mA (miliamps) into A (amp).

To convert the needed value for the current with the simple use of dimensional analysis (a term for checking the relation of one unit to another): 20mA * \frac{1A}{1000mA} = 0.02A

 R = \frac{V}{I} 

 R = \frac{9V}{0.02A} = 450Ω 

So we need 450Ω to balance out the circuit.

Summary

Before we get to the practical part of electronics, we have to be familiar with the inner workings of the circuit, the main thing we are working with when go tinker around.

Objects are made up of atoms and each of these are made up of smaller particles, namely: protons, neutrons, and electrons. Each of these particles can be found numerously, with the protons and neutrons staying in the center forming a nucleus and the electrons orbitting around the nucleus.

However, there are also electrons that hang outside of the atom shell called the free electrons. The number of electrons dictate the charge of the particle. Having too many is considered to be negatively charged and having an inadequate number is considered to be positively charged.

The charge of a particle also dictates how they interact with the other particles. Like charges repel and opposite charges attract.

Conductors such as metals have a structure that is loosely holding these electrons with only the nucleus (the protons and the neutrons) stay constantly which is why conductors can still hold their form. Insulators such as plastic, on the other hand, have an atom structure that is very strict, the free electrons cannot freely move from atom to atom.

Electric circuits are made up of conductors and insulators, regulating and handling electric flow through different electronic components (which will be talked about in the next part).

Inside of the circuit, there is a lot of electrons. These electrons are just staying on the component unless there is force that makes them move and be pushed around on the circuit. If the force exists to push around the electrons, these electrons will start a domino effect wherein one electron repels the other then that electron will also repel the other electrons.

Then if we have a complete circuit that is working, these electrons will just continually push other as they are being attracted into the positively charged terminal then being pushed again by the negatively charged terminal, creating a loop that just keeps going. This is what an electric flow is.

There are three main variables in a circuit:

• the current — the flow of the circuit
• the voltage — the strength of the flow of the circuit
• the resistance — the limiter of the strength or else the components of the circuit may recieve too much flow and burn out

When we try to combine these variables in a circuit, we can use a formula to check their values. This is also useful if we try to solve for some values in order to balance them out and not get an extreme situation where we either burn out the components or made the components too weak.

 I = \frac{V}{R} 

That formula derived is from the Ohm's Law which states the current is proportional to the voltage but with the resistance being considered.

---

OK. We are mostly done with the theoretical parts of electronics. I decided to make this into a two-parter since it is quite long (about more than 40 minutes worth of reading in total time). It is better to split it up into two 20 minutes sessions than a whole 40 minute session. Besides, spaced repetition is a good learning technique than cramming down the whole thing down in one swoop.

There will be an upcoming part two of this post, so stay tuned on that!

(Re)Sources:

• Books

  • Electronics For Kids (No Starch Press)
  • Part 1: DC Circuits on Fundamentals of Electric Circuits, 6th Edition (Alexander & Sadiku)
  • Part 1: Fathoming the Fundaments of Electronics on Electronics For Dummies, 3rd Edition (Wiley and Sons Inc.)

• Videos

  • Basic Electricity - Resistance and Ohm's Law by Afrotechmods
  • Basic Electricity - Voltage by Afrotechmods
  • Basic Electricity - What is an amp? by Afrotechmods
  • Electric Charge from Crash Courses
  • How to use a breadboard by
  • LED Basics by Afrotechmods
  • Simple guide to electronic components by bigclivedotcom

• Web

  • Breadboard on Wikipedia
  • Coulomb on Wikipedia
  • Difference Between EMF and Voltage from Difference Between
  • Electric charge on Wikipedia
  • Electromotive force on Wikipedia
  • Electronics for beginners on Explain That Stuff
  • Learn the Basic Electronic Components from Build Electronic Circuits
  • What is the difference between emf and voltage? from Quora
  • What You Need to Know About Current, Voltage and Resistance from Build Electronic Circuits
  • Voltage on Wikipedia

Choose your own learning adventure

Well there are some things that are not discussed in here (which may or may not be added) such as:

• Electronic schematics/diagrams
• Practical application of the electronics (psst... it is what the next part of this post is about)
• A deeper theoretical integration of the fundamental concepts

Author's Note

Image credits to Unsplash, Wikimedia Commons, and me. All credits deserve to the author with their rights. 😁

This Unsplash photo is from Jens Johnsson, the components photo from Wikimedia is from the author, Kae. While I created the pictures with Paint 3D from Windows (IDK how to Illustrative/Inkscape/Sketch, OK?).

All pictures used (including mine, if anyone wants to use it for some reason) are free for use for any purpose (mostly).