Lessons: #4 Soldering

Ok. Lets say you wanted to take that LED circuit we "made" a while back in lesson 2 and make it into a permanent circuit. How would you go about doing that? You wouldn't super glue the leads to the wires and you sure wouldn't tape them together. So, how would you do it? 

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Here's the answer. It's soldering! (Yay..!) Anyways, it's essentially a metal super glue. Solder is a metal that melts at a relatively low temperature; about 360 degrees fahrenheit to be exact. When you want to connect two components together, you tie their leads together and heat them up to that temperature so the solder will melt and flow around the contact, then hardening to get a more-or-less permanent bond. The process is pretty simple, it takes a little practice, but once you do it a few times, simple soldering is a piece of cake. Let me take you through some of the basic steps. 

1. Plug in your soldering iron and let it set out for about five minutes; giving it time to heat up.

2. Tin your iron. You'll do this by taking a bit of solder and touching it to the tip of your iron. This'll help with the heat transfer. 

3. Twist the leads of your components together, preferably a couple times. This will allow the solder to flow in between the joints, giving you a really solid connection when it hardens.

4. If you're soldering some delicate components together, you'll want to put some heat sink by the components base so the heat from the iron won't burn it out. Heat sink is usually just a small copper clip you clip onto your component that will redirect the heat into the clip instead of allowing it to go directly into your component. 

5. Hold your iron against the soon-to-be connection for a few seconds.

6. With your iron still on the joint, take your solder and touch it to the joint. The solder should flow right into it. 

7. Pull iron away and there ya go! Don't touch it for a bit, it's most likely hotter than no other. 

For the more visual learners, here's a Youtube link for ya. 

Lessons: #3 Our Very First Circuit

Lesson three is upon us! Here today we are going to (kinda) make our own circuit. We know almost enough already to do so so why not? So... what kind of circuit? One that will light up an LED, or a light emitting diode. Now, before we can get started, we need to discuss something, and that'd be a component called a resistor.

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Remember from lesson 2 when there was the water tank analogy, and the width of the spout was the resistance? Well, sometimes you really need some resistance in a circuit for it to function properly. Imagine your spout was really, really wide and there was an enormous amount of volume traveling through it and you were trying to fill up a small cup. The cup would almost immediately fill up and start to overflow, spilling water everywhere. So, in other words, a complete catastrophe. Same concept goes for electricity. Imagine you're building an LED circuit. The LED is your cup, the battery is the tank and the resistance is your nozzle width. Now, you obviously need a certain resistance so your cup doesn't overflow too quickly and, well, one that's not too thin so the water doesn't slowly drip out like a faucet in an old building. You want a resistance that will fill your cup up right at a nice pace. Now, back to the circuit. You need a resistance that will keep your amps right in the LED's butter-zone. So, how do you get that resistance? Use a component called a resistor! A resistor is a component that will deliver a certain amount of ohms to your current so the amps are satisfactory. Now, how do you find out how many ohms you need? 10? 1,000? Simple. Do you remember Ohm's Law? You know your voltage because you have to know what kind of battery you're using, and you also know your amps because your LED will tell you how much you need. So, let's figure this out.

Let's say we have 2 AA batteries that gives out a total of 3VDC (volts direct current) and the LED, for our convenience, operates at 3VDC at 25mA (milli amps). So, we know our numbers, so all that's left to do is plug and chug! I = V/R plug our numbers into our equation: 0.025A = 3VDC/R. Once you do the math, you should come out with 120 as your answer. So, for your LED to opperate well, you'll need a 120 ohm resistor in your circuit!

For more awesomeness, head to lesson 4!

Lessons: #2 Circuitry Basics 2

So, besides AC, or alternating current, and DC, or direct current, there are other specifications that will help define the electricity your dealing with. What's the currents pressure? What's it's volume? Whatever circuit you're dealing with, you need to know these things.

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Voltage (volt) is current's pressure and amperage (amp) is the current's volume. Another important variable to know is how much resistance the current is encountering and we use "ohms" to represent that. Now, take a look at the diagram to the right. We have a tank full of water with a spout at the bottom. The difference between the two is the resistance, or "ohms," which is another very important factor. Now, the amount of water is the "voltage," the width of the nozzle is the resistance, and the "amps" is a result of the resistance. Now, you need to know that more resistance = less flow and this diagram illustrates that. The thinner the nozzle the more resistance there is and that reduces the volume of water allowed out, or amperage. There's a really simple equation out there to calculate this and that would be Ohm's law. I = V/R  where "I" is your amps, "V" is your current, and "R" is your resistance. This makes since because 1/1 = 1 and 1/2 = .5 proving the illustrations above are true.

Want more? Head on to lesson 3!

Lessons: #1 Circuitry Super Basics

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Ok, so while we're on the topic of cool gadgets like projecting keyboards and remote controlled paper airplanes, why not talk about how they work? I bet you're curious as to how the guts of these contraptions make them do what they do, so... I'm going to teach you! But before you get to understanding something complex like a projector, we need to start with the basics.

Look at the picture to the right. Kind of obvious what's going on here, right? You have a battery that powers a bulb. Now, this picture isn't correct for a few reasons but I'll discuss those later.

There are two ends to the battery: the positive end and the negative end. When a circuit is formed, the electrons flow from positive end to the negative end; powering any components that come between them. Well, that's how we initially thought it flowed; but further study showed electrons flowed from negative to positive, but it was too difficult to change the math equations we had already formed to fix our mistake so we continue to think it flows the wrong way. So, any way, there are two more broader classifications of electric flow out there. There's AC voltage and DC voltage, or alternating current or direct current. There's basically only one difference and that's how they travel. Direct current is the kind of electricity you'd find pumping through your phone or flashlight. This electricity flows in one direction; kind of like water flowing through a pipe. Now, alternating current does something funky. Imagine you have that pipe of water, but instead of the water constantly flowing in one direction, it sloshes back in forth. It goes forward then back, forward then back. It still moves in a general direction, kind of like taking two steps forward and one step back. You'd find AC in your outlets.

Hopefully, you very vaguely know how electricity flows now. So, why do you think the diagram above is false? Think about it. That light bulb was probably made to be powered from an outlet, but it's hooked up to battery. What's the difference? Batteries supply DC and outlets supply AC! Plus, outlets supplly much much more power than a dinky little battery.

So, want more? Go on to lesson two!