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==Introduction==

Welcome to Basic Electronics! This workshop is designed as a primer on the field of electronic circuits. You will be introduced to the fundamental concepts of electrical engineering, including both signal flow and basic circuit analysis. Breadboards are introduced, and you will then experiment with simple components and build several simple circuits. Finally, you will learn the basics of soldering, and assemble a permanent first prototype of your circuit!

*Electricity and Ohm’s Law

*Making a permanent first build

*Breadboards

*Printed Circuit Boards (PCBs)

Nothing! This course is designed as an absolute introductory primer in the field of electronics.

DaBL has a series of Workshops designed to the teach the fundamentals of modern low-power electronics. This Workshop is the first step in that process. After mastering this material, there are two paths which can be taken, either separately or concurrently:

===Breadboards are the best===

We’ll be using three components (a 9V battery, an LED, and a resistor), plus a very special piece of equipment: the breadboard. The '''breadboard''' is an incredibly handy tool used to rapidly assemble and modify a circuit; to '''prototype''' without the need to solder. A series of isolated metal rails are mounted inside a plastic housing, which can be accessed through holes on the breadboard's front face. The rails themselves allow you to electrically connect components, and the holes in the plastic housing hold the components in place. Take a look at the top face and the internal connections:

'''Setting it up'''

Push those legs in all the way! Now you have access to power from both the top and bottom of the breadboard. You won’t always need to do this; in fact, you may encounter projects which require more than one source of power, in which case you most assuredly will ''not'' want to do this. But since we’ll only be using one source of power in this course (the 9V battery), wiring the same power to both the top and the bottom makes building the circuits easier.

===Connecting the components===

{| class="wikitable"

|1. the positive rail to the long leg of the LED

|}

Your complete circuit should now look something like this:

and your LED should be lit! Here’s another important note: as long as you’re correctly following the internal connections of the breadboard, it’s up to you where on the breadboard you wire up your circuit. It also doesn’t matter which order you place your resistor and LED in: since there is only one path for the current to take, the current is the same everywhere, and it makes no difference which component comes first. So you could also connect your circuit in a different way and it would function exactly the same:

===Aside: Uh oh, something went wrong…===

==Activity 2: Schematics and components==

===Voltage Source===

A voltage source creates a potential difference; in the analogy, it is the pump pushing water up to the top floor of the house. There are many types of voltage sources; the most common is the battery. Batteries are represented in schematics as such:

===LEDs===

The '''LED''' is a special type of diode that emits light when current flows through it. “That’s great!”, you’ll say, “But what in the world is a diode?” A '''diode''' is a ''one-way voltage-controlled current gate''. We won’t get into the semiconducting properties of the materials which make up diodes; you can simply think of them as a valve in the water analogy - one that only works if the pump pushes water high enough into the system. The diode '''insulates''' when there isn’t enough voltage across it; no current will flow through. When enough voltage ''is'' dropped across is (called the ''forward voltage''), it opens up and allows current to flow through - it '''conducts'''. In the case of a light emitting diode, when the gate opens and current is flowing, part of the energy of that flowing current is converted into photons; light!

===Resistor===

Resistors are not polarized; you can connect them in either direction, and they will function the same. Their ''nominal resistance'' is stated in Ohms (Ω).

===Going further===

Based on what you’ve just seen, the three quantities of electricity which we introduced earlier - voltage, current, and resistance - are clearly tied together somehow. It turns out that they’re actually mathematically related - and that relation is very easy! The equation, called '''Ohm’s Law''', will be one of the most important tools in your toolkit:

'''V''' is the variable for voltage, '''I''' is for current, and '''R''' is for resistance. If you know two of the variables, you can solve for the third! Let’s do a simple calculation. We actually know the total ''V'' for the system: 9V. The LDRs you are using have a minimum resistance of 3kΩ, so we also know ''R''! All we need to do is solve for ''I''.  

==Activity 4: Potentiometers, and series vs parallel==

You already know that changing the resistance of part of a circuit also changes the current; more resistance equals less current, and less resistance equals more current. So by extension, varying ''the resistance between two paths should change their currents as well''. Congratulations: you’ve just made a current crossfader!

==Activity 5: Soldering==

The PCB also has a layer on top of the copper called the '''solder mask''', which protects the internal traces from damage. On this board, it is purple. Usually on top of the solder mask, the PCB will also have a '''silk screen''', which contains text and images helpful to anyone looking at the board. This is the circuit you’ll be soldering together:

You’ll notice that it’s just a combination of two of the circuits you’ve already built, with one addition: a '''switch'''. This switch has a single '''pole''' which can only connect to one other pole; it is said to only have one way to be '''thrown'''. Therefore, this is a '''S'''ingle '''P'''ole, '''S'''ingle '''T'''hrow switch; '''SPST'''.

Congratulations; you have just made a permanent prototype of your first circuit! Test it out to make sure everything works.