Introduction to Electronics - Part 1

Every so often, I get someone coming up to me, asking me for advice has to how to make their own electronic gizmo. More often than not, they have little to know experience and when they do try to do it on their own, it's more of an adventure back and forth to RadioShack to replace blown parts.

Instead of jumping into a guide of "How to Make Your Own Lightsaber" and other awesome stuff, we need to start off with some theory, because, like it or not, you're going to need it if you want to make your own geeky tech projects. But what credentials do I have, you ask? Why should you bother listening to me? Well, I have a low-voltage license and I'm in the 97th percentile for the country on this stuff. I think I have a vague idea as to what I'm doing.

Like many other subjects you learn, let's divulge into a bit of first-aid first. Soldering irons. They can burn at around 3300 degrees Farenheit. To give you an idea as to how hot that is, water boils at 212, and that can give you some nasty first or second degree burns. A soldering iron and hot solder can do much, much worse. So when we finally get to the point of soldering, as I'll explain later, make sure you're near a faucet or something cold in case you get burnt. Now, there's also different types of solder. There's rosin core, acid core, and even lead core. Lead core, if my knowledge is correct, is very bad and outlawed in many areas. Granted, other types of solder are MADE with lead, but it's not what it's mostly made out of and is therefore a little safer. However, when you do solder, you will generate a lot of smoke. Make sure when you get to this, you work in a well-ventilated area. Breathing in especially acid core for many hours on end will make you light-headed and you may start seeing things moving that shouldn't be moving. Trust me, I've had this happen during the long projects. The one I like best is 63/37 Rosin Core solder. It flows very nicely onto PC boards and into wires, making it easy to work with. If you can't find this, 60/40 Rosin Core works just fine. It comes in different gauges, just like wires, so figure out what size you need and go with it.

Remember when you were younger, someone older than you would warn you as to why you couldn't put something in outlets and such because it'd hurt or kill you? Well, they have a point. When dealing with electricity, it takes very little to harm to the human body. According to this website, this is the information on amperage and how much it takes to kill you:

"While any amount of current over 10 milliamps (0.01 amp) is capable of producing painful to severe shock, currents between 100 and 200 mA (0.1 to 0.2 amp) are lethal. Currents above 200 milliamps (0.2 amp), while producing severe burns and unconsciousness, do not usually cause death if the victim is given immediate attention. Resuscitation, consisting of artificial respiration, will usually revive the victim."

To give you a better idea, amperage can be calculated by power (watts) divided by voltage. So let's take a 100-Watt lightbulb off a 120-Volt outlet. 100/120 = .2 Amps. That's enough power to do a lot of damage to you, and think of how hot a 100-Watt bulb can get, even if you aren't in contact with the filament itself. (To find how much power your electronic devices that you plug in take, look at the back and multiply the volts times the amps. With a lot of time, patience, and relatively simple math, you can see if the power company may be ripping you off or not.)

And when you're soldering, the way I was taught was to keep at least an inch of solder past your fingers. It gives you space away from the hot solder and the iron, but enough leverage so you can keep control of what you're working on.

Time to divulge into parts you'll probably use when making your stuff.

The Battery.


As you can see, they come in many different shapes, sizes, and voltages. Assuming you're going to make something that can run on batteries instead of plugging in, you'll need to be able to figure out what kind you'll need and use. If, chances are, you're making something that will light an LED at the flick of a switch, then a simple, round 3V like the bottom picture will suffice.

Using this same picture, note the "+" sign on the left half. The other side with the texture is the "-" side of the battery. If you're not already aware, electricity flows from the negative side to the positive side, so when you get to constructing your circuit, you need to maintain the same polarity throughout your circuit, otherwise you'll just blow stuff up and costing yourself even more money. We'll go into detail later about polarity for the different parts you'll come across.

The Light-Emitting Diode.




As you can see, light-emitting diodes (also known as LEDs) come in a vast array of colors. Some are small, some are big, and some even emit ultraviolet light. Some of these can get rather pricey per LED, so it's best to make sure you use the right polarity with your project. Like I said above, polarity is rather important in electronics. And, like above, electricity flows from negative to positive. So when you build your circuit, you would attach your negative side to your battery to the negative side of your LED. Below is another picture to help show how to find the negative side of your LED. I'll also explain it.


So there's two names for the sides of your LED. Anode and Cathode. The longer name is the negative one. But when you're holding one, those things can be awful small, so how do you know which side you have? If you've bought regular LEDs, then you may notice that one of the metal leads coming out of it is longer than the other. The SHORT lead is the NEGATIVE one. If you so happen to have cut off these leads or got them with the leads at an even length, then there's another way to find out which side is which.

You'll need to feel around the rim with your finger. It's round ALMOST all the way around. The side with the negative lead will either have a flat edge or a notch. If need be, you can also take a magnifying glass and look closely. It's not entirely difficult, but sometimes it may take some time in order to remember the difference, so don't worry if you have to constantly recheck for polarity.

Before I finish this, you may be wondering what that little triangle thing in the last picture is. The one of the very bottom of the photo. That is the schematic symbol for a LED. The little arrows are important, because they mean that it's a "Light-Emitting" diode instead of just a regular diode. The line in front of the triangle signifies the negative side. It'll be easy to remember if you think, "the side with the line has a sideways negative sign" or something like that.

Until next time!

DIY - Floppy Disks

Do you have a stack of floppy disks hanging around with no use for them? Wondering if you could ever find a use for those old cards? There's plenty of projects to get started on!

Back at college, I joined this group called "Women in Computing" and for our first meeting, we got together and took apart some old floppy disks. Little did I know, we were making earrings! Yes, actual wearable earrings! Things you'll need:
2 Floppy disks
2 V-Rings (Or large jump rings)
2 Jump Rings
2 Earring Wires
Pliers

You can actually get the bits from your local craft stores such as Michael's, AC Moore, Joanne Fabrics, and much more. I'd hit up your local shops first to support small businesses. They probably don't sell them in single or double pieces, so don't worry too much if you buy a whole box. Chances are we'll find another idea to use them with.

Start out by taking apart your floppy disks. We'll want to get at the small, circular bit in the center. Crack them open, cut them, however you want to do it, just try not to break the small piece in the middle. Once you have your circle, look for the hole shaped like a square by the end. We'll grab our V-Ring and hook it in there. Feel free to use your pliers and maneuver the metal and bend it so that it fits. Next, take your jump ring and put it on the v-ring. This will take some more bending with your pliers, but it shouldn't be too difficult. Keep it open so that you can attach the earring wire. Lastly, take your earring wire. Attach it to the jump ring and close the jump ring.

Your final project is going to look similar to this:



Ta-da! You're all done and you've got yourself a set of floppy disk earrings! Congratulations! Feel free to throw away your destroyed plastic of the floppy disk if you wish.

If you have other floppy disks that are still in tact, then here's a list of projects that you can also do, no matter what size you have:

Great for the kids! Help keep the desks clean by creating a fun, unique way for them to put away their pens, pencils, markers, and other craft supplies. The picture shown below involves drilling through the plastic and tying the holes together or using zip-ties. While this is simple and effective, it can also be a hassle. If you would prefer to glue or tape it together, then have at it!



This works especially if you have some of the older disks, because they're much larger than your "modern" 3.5" floppy. The inside can be sealed together with various techniques: Loctite or even duct tape. Loctite is especially built for plastics, so if you feel comfortable using it, I suggest you do so. It'll take some time for this one, but it'll be worth it. You'll start off sealing your floppy disk ends to one another, starting with the sides. The bottom will be a glue along all four ridges, then pressed up to the bottom of your other four disks, and held in place until the glue is dry. Once it's nice and dry, feel free to fill it with soil and a plant of your choice! I would recommend keeping it small, so something like a small desert cactus or a herb or small flowers would be the best choice. Ask your local grower for suggestions as to what you can keep in a small pot.



What about coasters? Over here gives information on how to recycle your old mouse-pads and floppy disks to make coasters for your drinks around the house! If you don't have a mouse-pad, then foam or cardboard does the same thing. If you don't have rubber cement, something like Loctite or super glue can also work. Feel free to paint or decorate your coaster however you want!




All images were taken from Google images. I do not own any of the pictures shown above.