Circuit Lab (Episodes)

=Circuit Lab=

Episode I
Continuing with my trend of the two previous help threads, (which will be linked at the bottom for anyone interested) I�ve decided to write a new shocking guide. A guide to that energizing event, Circuit Lab. If you were at all like me when you got these rules, you might�ve said �wtf mate?� But fear not, my fellow shocked-in-the-fingers-friends, for I�ve prepared a few notes, definitions, and various helpful items that hopefully won�t short circuit (I�ll explain that later) your brain.

First of all, let�s answer some questions that you may have if you�re completely new:

-What is a 'circuit'?

Let�s take an example of a battery, for now. The battery has a positive (+) end, and a minus ( - ) end. When you touch a wire onto both ends of the battery at the same time, you have created a circuit. What just happened? Current flowed from one end of the battery to the other through your wire. Therefore, our definition of circuit can simply be a never-ending looped pathway for electrons (the battery counts as a pathway!).

'''-But Demosthenes, I don�t get it. What�s current? What are all these positive and minus things?'''

Why thank you for your hypothetical question, my reader, because this is the next thing we should understand: electron flow. What is an �electron?� To put it simply, an electron is an atomic particle which carries a negative charge. These electrons spin around the nucleus of an atom, which has a positive charge, and is located in the very center of the atom. The concept of �electricity� has to do with these electrons and with their �electron flow.� Do you remember the example of our battery? This battery takes these negatively charged electrons from a chemical reaction inside the battery, pushes them out of the negative end of the battery, and into the wire. These electrons will then bump electrons in the atoms of the wire over and over until finally electrons arrive back at the positive end of the battery. Elements which allow this process of �bumping� those electrons on over determines how conductive the element is. So, when there�s a current, it�s just electrons bumping each other from atom to atom and flowing on.

-Oh, so I get it Demosthenes, you could just put a wire onto one end of a battery, and the electrons would still bump each other?

No, you could not. As stated before, in our definition of the circuit, a continuous loop is required. But think about it scientifically: If you did attach the wire to only one end of the battery, where would the electrons go that got bumped to the opposite end of the wire? That is why there needs to be that continuous loop of wire: the electrons need somewhere to go.

'''-Okay, I gotcha Demosthenes! I know about the flowing thing now, but what about all that �voltage,� �resistance,� and �ampere,� stuff they�re going to ask me on the circuit lab tests? ''' Ah yes, you certainly know how to ask the right hypothetical questions, my esteemed reader� To help everyone understand these 3 concepts, I�m going to use an example from sports. Imagine you are the coach of the New York Yankees baseball team. Aside from dealing with being the Devil on Earth, you also have to deal with keeping a winning team amidst the ever-so-polite New York fans and cutthroat media. You want to make your team the best it can be � focusing on 2 big things: scoring runs, and preventing runs. If you can do both of these�you�ll be an awesome team, but no one is perfect. So naturally, you�re going to have to choose one area to focus on: say you want to score more runs � let�s relate this to the concept of �amperes.� The amount of runs you make is your score � the more you get the better your chance of winning. Similarly, amperes measure the amount of current you have flowing per second through an area: is it a lot, or a little bit? Now, if you want to win the game, you don�t necessarily have to score a whole lot of runs, you just need to score more than your opponent. So, maybe your resistance to their scoring of runs will be high � and resistance to current flowing is also one of our important terms we need to know. Now, how do these concepts of amperes and resistance relate, straying from the daemons for now? If you multiply the resistance by the amperes, you have the voltage of a circuit (remember, we�re always talking about in circuits here, not on a baseball field). This relationship was discovered by Georg Simon Ohm, and it says, simply, that:

$$V = I x R$$

Or

Voltage = Current times Resistance

If you are having trouble, think back to the baseball example: you can have a high chance of winning (voltage) by either scoring a lot of runs (high current) or having good defense/pitching (resistance).

-But, Demosthenes, I was the kid in Little League who kicked dirt in the outfield, and I just don�t get Voltage�

Don�t worry man; I kicked dirt everywhere on that field�. As for voltage, it�s definitely the hardest of the three concepts to understand. Some really smart guys call it �potential,� other people use analogies of a water tank. The links at the bottom will explain all this juicy stuff to you: I, again, will develop my own analogy (I won�t grill the Yankees this time):

Have you ever pumped up a super-soaker in order to blast your little brother? If so, you�ll be pleased to understand my next example (no, not about pwning little brothers, although that�s fun). The harder you pump that super-soaker, the harder that stream is going to be when it comes out of the gun. You can think of voltage like that. Voltage is the potential for that water to go very quickly out of the gun: the more you pumped, putting more �voltage� in, the faster that water will go: but sometimes you will have a �multi-functioning� nozzle which even allows you to adjust that water speed even further. Suppose you�re a n00b and you don�t have a steady arm to hold the gun, so you want the water to go out in a �wider� and �bigger� stream, you might change the nozzle to a bigger opening. What you�ve just done is changed the amount of space that the water is allowed to go through: the water is now given a much bigger space to flow through. The �voltage,� or potential, of the water to go fast and give bruises is still high, but now you�ve taken away from it�s hitting-power by spreading it out. Anyone know where I�m going next with this? The bigger your nozzle gets (think of it like the resistance), the smaller the hitting power (current (which is a speed in electricity too!)) is going to be.

'''-Wow, Demosthenes, the water example makes it easier to understand. So it�s like if I can get one of those huge guns, with more �voltage,� I might be able to get a lot more �amps� out of it (how hard it hits).'''

If anyone is at all confused by these examples, I urge you to read the links I placed throughout the guide, in addition to the links at the bottom of this post. Note that these examples are not perfect and have logical flaws, but I�m just trying to put a model for the relationship of voltage, amps, and current into your heads. If you already understand circuitry, this probably didn�t help too much. I�ll make a guide for you next, but first thing�s first.


 * 1) Extensive Site about Circuits
 * 2) "Really Basic Electronics"
 * 3) Analysis of resistive circuits

(that last one is more advanced)