TUTORIAL: INTRODUCTION TO ELECTRONICS
By: Sandro Alberti Prepared for: TEEN CENTER
Don’t burn down the house; make your holiday candles with electronics!!
FLICKERING LIGHTS HAVE A COMPUTER CHIP INSIDE THE BULB You might think that you need a computer to program flickering lights. But in this tutorial you’ll use LED lights that already flicker all on their own (they just need electricity). How do they do that? They have a very tiny ‘candle flicker’ computer chip inside the bulb.
THERE ARE MANY WAYS TO MAKE IT LOOK LIKE A FLAME When I created this tutorial, I decided on 6 LEDs as the best way to create the effect of candle fire (2 clear yellow and 2 diffused yellow and 2 red). But you can always decide for yourself. Maybe you only want yellow color in your flame (or only red), or fewer than 6 lights.
HOW ELECTRICITY FLOWS At a basic level, batteries hold electricity, and electricity comes out of a metal wire (’positive’, normally colored red) and back into the battery holder through the ‘negative’ wire (normally colored black) and it continues to loop over and over very fast (as long as the 2 wires are touching or closing a loop). OUT
BRIDGE/LOOP #1 electronic
BRIDGE/LOOP #2
INTRODUCTION
When the red and black wires are loose and not closing a loop, then nothing happens (but anything that you connect to the red wire has electricity ready to go out, and anything connected to the black wire is always ready to bring electricity back to the batteries). And wherever you connect the red and the black paths, electricity will go through (an ‘electricity bridge’). And you can connect the red and black paths at many different places (not just one).
IN
Normally electricity flows through conductive materials like metal (that’s why wires are made of metal). An LED is just another piece of wire that electricity can flow through (and when electricity goes through it, the bulb lights up). You will also be using resistors, which are another piece of wire that electricity can flow through (and they ‘resist’ the electricity and make it less strong so that it doesn’t burn an LED bulb with too much current).
LED RESISTOR
So if you connect the red wire to a resistor, and the resistor to an LED, and the LED to the black wire (full loop),... the LED will light up (because electricity will flow all the way through). Easy as that. And if you split the paths with more wire, you can make another loop and light up another LED (or 5 more loops with 5 more lights, like we’ll do in this tutorial).
TOP OF PLUGBOARD (tie points) point 17C 7
E
C D
B
A
O1 1T
wire #1
O 8T
34
1 BOTTOM OF PLUGBOARD (wires)
INTRODUCTION
PLUGBOARDS HELP KEEP EVERYTHING NEAT Splitting wires (or connecting many wires together) can easily get messy. If anything gets just a little bit loose, then the electricity doesn’t get through at all, and nothing works. That’s why someone invented... the plugboard (also called ‘breadboard’). Plugboards are basically neat rows of wires with holes on top that other wires can easily plug to and stay in place (the holes are called ‘tie points’). In this tutorial we’ll be using a tiny 170-point plugboard that has 2 rows of 17 short wires inside (34 wires total). Each wire in this plugboard has 5 tie points to connect to it (so it’s easy to plug in up to 5 LEDs between 2 wires, but you’ll need to get creative in order to plug in 6 LEDs , and also 6 resistors). The wires are numbered 1 to 17 from left to right, and then 18 to 34 on the second row. For each wire, the tie points are labeled A to E, top-to-bottom.
TUTORIAL IN 5 STEPS
LET”S MAKE IT ! STEP 1 Connect your battery positive red wire to plugboard wire #1 (at 1A). And connect the battery negative black wire to plugboard wire #9 (at 9A). We just need to keep some space for the LEDs and resistors between the red and black wires, so the black wire could have been connected to wire #8 or #7 or #10, but #9 is good enough). So now wire #1 is part of the red wire path going out of the batteries, and wire #9 is part of the black wire returning into the batteries).
WIRE #1
WIRE #9
WIRE #18
WIRE #27
Let’s make the red and black wires even longer, by connecting them to plugboard wires #18 and #27. Do that by using a jumper wire between 1E and 18A, and between 9E and 27A. The jumper wire looks like a resistor, but doesn’t have any resistance (the resistors in this tutorial have many colored stripes, and the jumpers have just one single black stripe). STEP 2 Next we’ll use a resistor to connect the black negative wiring to plugboard wire #2 (from 9B we’re bringing it right next to the red wiring in wire #1, to 2A). Now you’re ready to light up your first LED, by using it to close the electric loop between red wire #1 and black wire #2 (plug the longer leg of the LED to 1B and the shorter leg to 2B (in LEDs the long leg is positive and the short leg is negative).
2A 9B 1B 2B
TUTORIAL IN 5 STEPS
STEP 3 Now you can use another resistor to connect another point in the black negative wiring (from 9C) to plugboard wire #3 (at 3B). Again we’re bringing it close to the red wiring in wire #1, in order to make another bridge with another LED.
3B 1C
9C
3C
Now we’re ready for the second light, which will close the electric loop between red wire #1 and black wire #3 (plug the longer leg of the LED to 1C and the shorter leg to 3C). STEP 4 For the next electric bridge, let’s try bringing the red wire closer to the original black wire (toward wire #9). Plug a resistor at 1D and at 8E. Now onto the 3rd LED light, which will close the electric loop between red wire #8 and black wire #9 (plug the longer leg of the LED to 8D and the shorter leg to 9D).
1D
8D
9D
8E
Now you can see why we extended the black and red wires down to wires #18 and #27 (there’s no more room for LEDs and resistors up at wires #1 and #9). STEP 5 So let’s repeat what we did in STEP 2 (but down in the lower rows). Plug a resistor into 26B and into 19A. And an LED between 18B and 19B. But we’ll connect the last 2 resistors in a different way than before (electric loops can be made in a bunch of different ways). Plug a resistor at 18C and at 25C, then finish the bridge with an LED at 25E and 26E. Plug a resistor at 20D and at 26D, then finish the bridge with an LED at 18E and 20E.
YOU’RE DONE!
A B C D E 18 19 20 21 22 23 24 25 26
SUPPLIES: WHERE TO GET IT ALL 170-point breadboard https://amzn.to/30MmNZi Even smaller option: 55-point breadboard https://amzn.to/2ZaCOqU (if you only want to use 3 LEDs) Jumper wires https://amzn.to/3aYcUcW Resistors (68 ohm) https://amzn.to/3C5SpH2 Two-AA battery holder https://amzn.to/3aWTQf2 Candle-flicker LED bulbs (2.1V- 10mA to 30mA) https://bit.ly/3C58IUv Another option: Candle-flicker LED bulbs (2V- 10mA to 30mA) https://bit.ly/3m1qT70 (choose the smaller ones labeled ‘super bright’) RESISTORS: HOW DO YOU CALCULATE RESISTANCE? This is the formula for the resistance that you need: (to choose the right resistor) R= (V1 - V2)/ I R is the resistance that you are calculating, in ohms. V1 is the voltage of the batteries (in this tutorial it’s 3V because we have two AA batteries). V2 is the voltage of the LED bulb (get it from the seller; in this tutorial we are using 2.1V LEDs). I is the ‘forward current’ that the LED can handle (normally 10mA to 30mA [0.01 to 0.03)).
Note: more forward current = brighter LEDs (but also more drain on battery). So for 10mA forward current: (a very dim light) R= (3 - 2.1) / 0.01 R= 0.9 / 0.01 R= 90 ohm (you can use a 90 ohm resistor)
And for 30mA forward current: (a very bright light) R= (3 - 2.1) / 0.03 R= 0.9 / 0.03 R= 30 ohm (you can use a 30 ohm resistor)
For this tutorial I chose 13.2mA: (kinda dim, like a candle) R= (3 - 2.1) / 0.0132 R= 0.9 / 0.0132 R= 68 ohm (we’ll use 68 ohm resistors)