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Soldering & Electronics 101

OVERVIEW & PURPOSE

A beginner-friendly introduction to electronics prototyping. Includes practical theory, tools, and techniques for working with circuits. This class takes you through the process of rapid prototyping. From concept to prototype, to integration with other forms of fabrication like woodworking. 



ELECTRICITY 101

Electricity can be thought of as a flow of negatively charged electrons between two points or terminals. One which repels the electrons toward one which attracts them. These two points have names. The point at which electricity flows from is conventionally referred to as “power” or the positive “+” terminal. Electricity then flows toward “ground” or the negative “-” terminal. 

In order for the electricity to flow, you must have an unbroken conduit or path that channels the electricity from one terminal to the other. This path is called a circuit.
 
Some materials are really good at conducting electricity, like copper. Others are not very good, like air. We call materials that are good at conducting electricity conductors, and those that are bad at conducting electricity insulators. These can be thought of as resisting or sometimes breaking the flow of electricity in a circuit. 

You can think of electricity flowing through a wire like water flowing through a garden hose. The pressure of the water is the voltage. The amount of water that is flowing through the hose is the current. The length and diameter of the hose is the resistance.
  • Voltage (volts):  a measure of the pressure, or FORCE, of electricity.
  • Current (amps): a measure of the AMOUNT of electricity.  
  • Resistance (ohms): a measure of the resistance to the flow of current.
These variables are all related to each other. For example, if you increase the resistance in the hose you will reduce the flow of water through it. If you want the water to flow faster, you have to increase the pressure. This relationship can be expressed in a basic equation called Ohm’s Law. We use this law to create safe electronics for people to use.

Ohm's Law (V=IR) relates Voltage, Current, and Resistance.



Hardware Component 1: Breadboard
  • Horizontal and vertical ‘rails’ help to temporarily connect electronic components together for rapid prototyping
  • Vertical lines labeled “+” & “-” on either side of the breadboard means that the rails they follow are electrically connected
  • One rail is the positive (goes to your power) and the other rail is negative (goes to ground). Do NOT connect to two together directly! This is called a short circuit
  • We can use insulated jumper wires to “jump” from our power and ground rails into the middle sections of the board
  • Numbered rows are electrically connected horizontally. That means that for example row 1 is connected horizontally from position ‘a’ to ‘e’. Row 1 is NOT connected to the row below it (row 2) and so on
  • The centre gap in the middle of the breadboard breaks the connection between the two sets of horizontal rows. Row 1 from position ‘a’ to ‘e’ is NOT connected to row 1 from positions ‘f’ to ‘j’ 

Hardware Component 2: Resistor
  • Device used to precisely restrict the flow of current through a circuit, protecting other components from damage and allowing them to function properly
  • Resistance is measured in Ohms. We use Ohm’s law to determine the resistor that should be used in a circuit, then we refer to the coloured bands on the resistor to identify the right one

Hardware Component 3: LED
  • Light Emitting Diodes are components that, when electricity flows through them the right way, give off light. We use them everywhere! Yay!
  • These components have something called ‘polarity’, they will only allow electricity to flow through them in a certain direction, from its power terminal to its ground terminal, or from the anode to the cathode
  • 3 tricks to identifying polarity on an LED
    • Look at your LED from the side: The longer side is the anode or power terminal, this side connects to your plus terminal on a battery
    • Look at your LED from the top: The flat side on the lip of the led is the cathode or ground terminal, this side connects to your minus terminal on a battery
    • Look inside the LED: The big half is the cathode or ground terminal, this side connects to your ground terminal on a battery



SCHEMATICS

A schematic diagram is a symbolic, simplified, and abstract representation of an electric circuit. It shows HOW things are connected together, and NOT WHERE they are placed on a breadboard. They use abstract symbols to represent electronics parts, then lines and junction points to show their connectivity.



SOLDERING 101

Soldering is a technique where you join two things (usually a electronic component and a circuit board) with solder. It’s like welding but on a micro scale. The tip of the soldering iron (the pencil shaped thing) gets extremely hot, like 400 degrees! The tip is then applied with solder (the spool of metal) to a component placed on your circuit board, fusing the two together and creating an electrical connection.

It’s important when you learn how to solder to do it safely. Some tips before you start:
  • DON’T TOUCH THE TIP WHEN IT’S HOT
  • Don’t leave the iron unattended when its on 
  • Holster the iron when it’s not in your hand
  • Solder can spit toxic burning chemicals into your eyes, so wear safety goggles
  • Solder is made of lead or other heavy metals which kill you over time; don’t eat it
  • Take every precaution not to breathe in the toxic fumes emitted by melted solder
  • Never solder on a powered “live” circuit; you will be electrocuted
Place the led and resistor onto protoboard according to the schematic from before. Protoboard does not have connection restrictions like a breadboard. You have total freedom to plan how your circuit will be laid out. You can also use helping hands to secure your protoboard before soldering.

Soldering Tips:
  • Before soldering two parts together, melt some solder onto the tip of your iron. This is called tinning and it can make soldering easier
  • Rest your arms on your working surface to give yourself more control over your movements
  • Don’t solder too fast, you may not allow enough time for the solder to create a solid connection before letting it harden
  • Don’t solder too slow, you may burn off all the flux in the wire and turn your solder into unmanageable goop
  • Don’t rest your iron on the component too long; it can damage it
If you make a mistake, don't worry! You can use solder sucker and/or solder wick to remove solder from the protoboard.

Maintaining your equipment:
  • heating and cooling your iron rapidly causes the tip to degrade and splinter. The thinner the tip, the more fragile it is.
  • use a brass sponge (NOT a wetted sponge) to clean the tip of your iron
  • don’t leave your iron on for long periods of time, the tip will oxidize faster
  • after you're done and while your iron is still hot, coat the tip of the iron in solder to help preserve it. 
Use a multimeter to check for short circuits (shorts) before you pack up. Make sure to wash your hands when you are done. 



RESOURCES

Where can I get parts?
  • Lees Electronic - fast and expensive
  • RP Electronics - fast and (slightly more) expensive
  • Digikey - reliable and affordable
  • Mouser - sometimes has better deals
  • Amazon - huge selection and mostly reliable
  • Ebay - super cheap and very slow
  • Aliexpress - super cheap and very slow
What other electronics communities are there?
  • Vancouver Hack Space
  • VIVO Media Arts
  • Vancouver Creative Technology
  • FreeGeek



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