## Tuesday, February 4, 2014

### Electronics Engineering 101: Lesson 2

Last time we determined what electricity is. Now we will find out how it works and what makes it possible for us to do cool stuff with it, like look at cute pictures of cats on the internet and text our friends about the awesome burrito we just ate, or make some delicious toast, or even turn on our lights using our cell phones.

In future lessons, after we have learned the basics of electronics and digital logic, we will even design some circuits. I'll teach you how to make a kickass alarm system for your home, for about a thousand times less money than some greedy corporation will charge you! I'll also show you how you can activate or deactivate your alarm, turn on your lights, open your garage door, or whatever using your smartphone, from anywhere in the world! Yes, you can do that! So, without further ado, Here comes Lesson 2!

2.1 Conductivity

Last lesson I mentioned Silicon. This element is very abundant on our planet, which is cool because it's also the most widely used semiconductor material in electronics. A semiconductor is just what it sounds like- a material that is a sort of conductor. It conducts electricity, but not as well as a conductor. An insulator doesn't conduct electricity at all, or at least not enough to make a difference. Conductors have lots of holes (or few electrons, however you want to think of it) in the valence shell of their atoms. So lots of electrons can move in and out of the valence shell.

Copper (Cu) is a great conductor, because it only has a single electron in its valence shell. Copper has the atomic number 29, which means there are twenty-nine protons in the nucleus. Neutral elements have the same number of electrons as protons, remember? So there are twenty-nine electrons in a copper atom. Since each electron shell can hold 2n^2 electrons, we can figure out that the first shell holds 2(1^2) or 2 electrons, the second shell holds 2(2^2) or 8, the third shell holds 2(3^2) or 18, and the fourth shell holds 2(4^2) or 32 electrons, etc. So, 2+8+18 = 28 electrons in the first three shells. Copper has 29, so that means it needs a fourth shell for that one extra atom. But that valence shell can hold 32 electrons, so there are 31 extra holes in the valence shell of a copper atom. A whole crapload of electrons are able to move into those shells, each carrying their little negative charge with them. That's why atoms with very few electrons in their valence shells are great conductors.

2.2 Charge

Remember last lesson when I told the funny Big Bang Theory joke? I promised we would talk more about charge? Well, here it is. We already know that protons have positive charge (so do holes!), and electrons have negative charge. This is important in electronics. I will not get into the science this time, because all we really need to know is how to use this stuff called electricity, remember? But basically, opposite charges attract and any system with differing charges wants to be be neutrally charged, with each positive charge having a negative charge to balance it out. Things that move a charge from one place to another are called charge carriers, and in electronics those carriers are usually electrons and holes. Electrons carry negative charge, and holes carry positive charge.

Charges can be separated. In a battery, for instance, through the magic of science that we will not get into because, fuck it, let's learn something interesting already, electrons are separated and a negative charge is pushed to the negative terminal, while a positive charge is pushed to the positive terminal. The battery now has electrical potential, or voltage, across the two terminals. Voltage is just a word meaning "the potential for charge to flow from one point to another," but it's way shorter to say. More later. The charges want to combine, with the electrons filling up holes and what not, but they cannot. The only way for that negative charge (electrons) to meet up with the positive charge (holes) is to go out through the negative terminal and go back in through the positive terminal. And the only way fro them to do this is by travelling through a circuit to get there, since they can't just travel through the air that easily. Although, as we will find out in future lessons, they certainly can travel through air and this is important!

2.3 The electronic circuit

Here we are! This is what we've been waiting for. Electronics engineering. A circuit is like a racetrack. That's why they call racetracks circuits, right? They are circular-ish and you start at one spot and have nowhere to go bu back to that same spot. Same in electronics. An electronic circuit (ckt for short!) is a collection of voltage source, wires, semiconductors, resistors, or other components that are all put together in a manner that lets current flow through the wires and stuff from one terminal of the voltage source and back to the other terminal. Easy, right? Now let's talk about some of those terms I've been using.

2.4 Voltage

Voltage, as I already said, is just electrical potential. It's basically a measurement of how much charge there is and how much can flow from a voltage source, like a battery. It's measured in volts, oddly enough, and its symbol is V.

2.5 Current

Current is the flow of electricity. It is the flow of electrons through a conductor, like wires or your body, if you're not careful. It is measured in Amperes, and its symbol is I.

2.5 Resistance

Some materials don't conduct as easily as others, or conduct in such a way as to lessen the amount of current. These are called resistors, and the resistance they offer is called... well, resistance. It is measured in Ohms and its symbol is R.

2.6 Ohm's Law

Ohm was a smart dude who did a thing. He figured out that there is a relationship between voltage, current, and resistance. And for that he got a unit named after him, the ohm, or unit of resistance. He gets bonus points for being the guy whose name people chant when meditating. Ohhhhhm! Ohhhhhhhhhhm!

Actual real scientists will give you a big complex formula to describe Ohm's law. But when an engineer goes into the lab and builds a circuit, it's always just V=IR. That's it. The voltage across an element in an electric circuit is equal to the resistance of that element times the current through it. Easy!

Next lesson we will learn how to use Ohm's law and other laws to make electricity work for us.

Questions

1. True or false: electrons are the only things that carry charge in a circuit.

2. Math check: if V equals IR, what does I equal?

3. If you have a circuit with a 10 volt source and 500 ohms total resistance, how much current flows through the circuit?

4. You know how ohms got their name, but who is "voltage" named after?

1. Because they say so.

2. Four, just like silicon.

3. The last (outermost) energy shell of an atom.

4. No charge.

5. The electromagnetic force.

## Thursday, January 30, 2014

### Electronics Engineering 101: Lesson 1

Since the big meanies at Skillshare won't let me teach anyone about electronics, and also since I need material for this blog, I've decided to start making instructional posts right here at Techazi! Plus, unlike the above mentioned site and most other educational venues, I won't charge a dime! Knowledge should be free!

So here goes the first lesson. I'll post some questions at the end, and if you want you can email the answers. I'll grade them, and also post the answers in the next lesson's post. Maybe some day when I can afford a camera I'll even do videos. Oh, also, it helps if you are familiar with algebra, trigonometry, and basic calculus. But even if you're not, don't worry. I'll explain everything you need to know as we go. Anyways, here goes lesson 1: Electricity!

1.1 Electricity

What is electricity? I know, you're like, duh! It's the stuff that makes stuff work. Everyone knows that. Most people also know that it has something to do with electrons. That's true. But how does it work? To understand what electricity is and how it works, we're going to have to learn a little about both physics and chemistry first. Sorry.

1.2 The Electromagnetic Force

According to physicists, there are four fundamental forces in nature. These forces basically pervade the universe and are what binds all matter together and causes things to be what they are and do what they do. The four forces that make life, the universe, and everything work (any Douglas Adams fans?) are:

1. The strong nuclear force. This is what holds atoms together. It really is strong.

2. The weak nuclear force. This is the strong force's little brother. It's basically the reason for radioactivity. But keep in mind my descriptions of these things are incredibly elementary, Watson, and a physicist would tan my hide if she read them.

3. The gravitational force. This one is obvious. The force most people know about, yet also the one we know the least about. Crazy!

4. The electromagnetic force. This force is responsible for both electricity and magnetism. Electro. Magnetic. Eh? Eh?? Both phenomena are manifestations of this force. Fun fact: light is also a manifestation of the electromagnetic force. Bet you didn't know that. So, in a way, you could say that electricity, magnetism, and light are fundamentally all the same thing. It's kind of like the Christian Trinity, only real.

The electromagnetic force is actually responsible for almost everything that happens in life, other than the stuff that the other forces control. Chemistry happens because of this force. We are able to think and see and feel because of this force. It is basically the force. Eh? See what I did there? Star Wars? Never mind.

All of these electromagnetic phenomena are made use of in electronics! But for now, let's focus on the phenomenon known as electricity.

1.3 The Electron

Let's say you have a silicon atom. Say it! We'll use silicon because it's the most commonly used semiconductor material in electronics (more on semiconductors and conductors in lesson 2). It's the reason why you've heard of Silicon Valley. It's also the fourteenth element (Si) on the periodic table. It's the fourteenth element because it has fourteen protons. Everyone knows that a proton is a little red ball with a plus sign on it, and it lives at the center of an atom with neutrons, which are little blue balls (cue Beavis and Butthead laugh) with no sign. Protons have a plus sign because they have positive charge. Neutrons have no sign because they have no charge, which is what makes Dr. Sheldon Cooper's joke in that one episode of The Big Bang Theory so funny. We'll get into charge later.

There are different atomic configurations of silicon, but all we care about is the neutral one right now, the one that has as many electrons as protons. That's the great thing about being an engineer; you don't have to really care about why, just as long as you can make use of the what. It's also why "real" scientists don't consider engineers to be "real" scientists. But fuck them, we're the ones who make the computers they use to bitch about how engineers aren't "real" scientists. Just kidding, real scientists. It's a joke. A funny joke. Well, laugh if it's funny! But anyways, what was I talking about?

Oh yeah, electrons. Everyone knows an electron is a little ball with a negative sign on it (because it has negative charge), and it zooms around the protons and neutrons of an atom like a little moon orbiting a little planet. These little thingies (scientific term) have different orbits, kind of like little moons around...  well, you get the idea. These different orbits are called "shells" and are spaced in lines of concentric rings around the nucleus of an atom. Oh yeah, the nucleus is the middle part where the protons and neutrons live.

Each shell has a strict limit on the number of electrons allowed to live there. But they can have less. Kind of like an apartment. The first shell can have two electrons. That's it. No mas. The second shell can have eight, and the third eighteen. Basically, each shell can hold 2n^2 electrons, where n is the number of the shell. There can be more shells, with more or less maximum occupancy, but we're talking about silicon, which has three. No matter how many shells an atom has, the outermost shell is called the "valence" shell, and the electrons in that shell are called "valence" electrons. Clever.

Remember how I said silicon has fourteen electrons? Here's where your basic math skills come in. If there are fourteen electrons, and three shells, and the first two shells can hold two and eight electrons, respectively, how many valence electrons does a silicon atom have? If you said anything other than "four," you should probably stop right now and go read something else. I hear Where's Waldo? is good.

Now, since the valence shell can have eight electrons, but only has four, electrons are free to move into (or out of) the spots in the shell where they fit. These spots are called "holes," by the way. Each hole wants to be filled (get your mind out of the gutter) so it can have the maximum number of electrons in the shell. So the silicon atom's valence shell is always wanting four more electron roommates to move in and help pay the rent.

It is that movement of electrons from valence shell to valence shell that is called electron flow. That flow is often called "electricity," and that answers the question I asked way back at the beginning of this lesson, and concludes the first of many electronics engineering lessons. Hurrah!

Next lesson: Conductors, Semiconductors, and Insulators, Oh My!

Lesson 1 questions:

1. Why are engineers so awesome?

2. Silicon is a semiconductor. Germanium is also a semiconductor. How many valence electrons does a Germanium atom have?

3. What is a valence electron?

4. Finish the joke. "A neutron walks into a bar. He asks the bartender, 'How much for a drink?' The bartender says, 'For you, __ ______.'"

5. What fundamental force is electricity a manifestation of?

## Thursday, January 23, 2014

### Lego is so much more than just blocks now

I remember playing with Lego blocks as a child- who doesn't? But back then you just got a big bucket full of bricks. No "sets" or any of that stuff. You just had bricks and your imagination. Well, for the past several years they have had awesome Lego machines that make me wish I were a kid again. Actually, screw it, you don't have to be a kid to buy these Legos, as the above video of a really cool Lego car assembly line shows.

I'm glad that a toy exists to inspire children to learn and experiment with technology. Oh yeah, there are Erector sets, too. Kids these days are sure lucky to have such great technology available to them. If you are a parent and want to buy a toy for your kid that will provide hours of fun as well as expand the mind a bit, I recommend something along these lines. Just make sure you stop playing with them long enough to let them have a go!

Sorry for the short posts- I'm still trying to get another laptop. Smartphones are great, but writing with them sucks!

## Thursday, January 16, 2014

### OK I'm back

Sorry Wordpress, I decided to come back to the ol' Blogger blog. I already do everything with Google anyway (how can one not?) so I might as well keep all my eggs in one basket. That's what you're supposed to do, right? Anyway, since I have gone on hiatus from university for now, I have decided to take up writing again. Specifically, I'd like to pursue screenwriting. But that's hard, so I'm working on some short stories and a novel as well. But I've always been quite the movie buff, and screenwriting is my new love, so I'll be posting more stuff having to do with film and filmmaking. I'll try to concentrate on the technical side of it, but I'll throw in some reviews, too. So, here we go! Let's see if I can remember to post more often...

Oh yeah, don't forget to follow me on Twitter. Yeah, I'm doing that now. Way ahead of the curve for a techie, huh?

## Sunday, July 1, 2012

### Why I am hating Battlefield 3

I have been playing Battlefield 3 for about a week now, and I must say it has the potential to be a great game. But I am hating it more and more for one reason- there are absolutely ZERO hardcore servers. Now, I have been playing nothing but hardcore for several years, starting with CoD2 and through BFBC2. I love hardcore because it requires a totally different style of play than normal mode. Hardcore tends to force one to actually use strategy, since a single shot can, and often does, kill you. Rarely will you see idiots running and gunning in HC mode. Instead, there is the satisfaction of using teamwork and skill to accomplish the objectives. Objectives. There is another thing I like about HC. People who play it are more likely to be interested in actually attempting to capture flags, destroy MCOMs, etc. than normal players. On normal mode the only objective seems to be to kill as many people as possible. Sorry, but if all I wanted to do was run around and kill people, I woulfd just play the campaign mode.

And speaking of killing people, I hate how Godlike normal mode makes a player. Yesterday I emptied an entire 21 round clip into a guy's back from twenty yards away and he then turned around and shot me. The only way to kill someone seems to be to get incredibly good at aiming for the head- something counterintuitive in the extreme, since anyone who knows how to shoot knows that you aim for the largest target- the upper body mass. It is still the part that I automatically aim at, and no matter how hard I try, I just can't make myself aim for the smallest target on a person's body.

But I digress. Where the heck are the Hardcore servers, EA? Or indeed any of the non-normal servers that you show in the filter? What is this Infantry mode that shows up? Don't know, because, you guessed it, no servers for it. I even set it to show full servers in the event everyone might just be playing HC? But no, ZERO servers. In fact there are absolutely no servers for anything but normal mode. What a ripoff. Hey EA (or Origin or whoever you call yourselves now) do you think I am going to go Premium or buy any of the expansions without Hardcore mode? Think again.

Edit to add that I did find out the problem- the Multiplayer update never automatically installed because when it downloaded the Xbox stored the download on the USB stick I had in it, rather than the HDD. So since I never rebooted til after I removed the USB, the update was never applied. I have enjoyed mad Hardcore BF3 action since a few days after this post.

## Wednesday, January 11, 2012

### Unplugged

In the twenty-first century, with all the scientific advances we have made, there should be no need for HomePlug Alliance's AV2 specification. According to the fine marketers, er, bloggers over at Engadget, the latest networking standard over home electrical wires offers up to Gigabit speeds without all the interference and performance problems that have plagued previous home-wired internet providers.

But you know what, why, in the twenty-first century, are we still not using Nikola Tesla's wireless energy technology? Then there would be little need for home wiring in the first place. Oh wait, that's right- Tesla developed wireless energy technology with the dream that energy would finally be free for all, ending a huge source of conflict in the world, where competition for resources causes more problems than anything else. Of course Edison called Tesla mad. "How then will we charge them for it?" was the industrialist's reply after hearing Tesla's grand idea for wireless transmission of electricity, collected from the radiation of the very cosmos. So while others are in awe of 'new' technology that keeps us enslaved to the merchant class, you and I should be quite upset that old technology meant to free us from energy dependence is still being suppressed. Read his Wikipedia entry for more info on one of the greatest scientists ever.