For everybody whoís ever wanted to make their own light-up Minecraft torch, and would like to play around with some fun electronics in the process, this Instructables project is for you! The electronics are explained well enough (and with links to everything needed) that somebody with absolutely zero electronics experience should be able to make this joule thief and torch.
Why a Minecraft torch?
The Minecraft torch is a real recognizable symbol of the Minecraft game, and I think having one that actually lights up is a lot more exciting than one that doesnít. And, itís probably obvious that I really enjoy Minecraft - I also made a Minecraft-themed candle-powered paper carousel and a Mooshroom hat. Plus, it keeps the monsters from spawning nearby!
Why a joule thief?
A joule thief is basically a relatively simple circuit that allows somebody to use "dead" batteries to power something that requires more voltage than the battery has left (it sacrifices current for increased voltage). So, itís a great way to re-use dead batteries, and learn some electronics in the process! The circuit typically includes an LED, which is lit up by the dead battery. In this Instructables project, I use a joule thief to power three orange LEDs on a breadboard, which all conveniently fit inside of the torch.
Why a breadboard?
Most of the Instructables projects on making a joule thief require soldering (because for people trained in electronics, this isnít a big deal and produces solid connections between wires). But for a beginner who hasnít soldered, itís much easier to use a breadboard. (I wanted this project to be super novice-friendly.) Additionally, it's a lot easier to include multiple LEDs in the joule thief circuit when doing it on a breadboard.
I am not an electronics person by education or training, but I am slowly learning! Iíd like to give special thanks to my father, who is an electronics engineer, and my husband, who dabbles in electronics, for much help in figuring out how to adapt the joule thief circuit to the breadboard for this project (and searching for toroids in Akihabara, Tokyo with me). Thanks for all your help!
Also, thanks to these other Instructables projects on making a joule thief:
Step 1: Materials Youíll Need
Youíll need these electronics materials to make the joule thief circuit - note that most of these items are linked directly to the product page on Jameco Electronics:
(two different colors is ideal)and a sharp knife or fine sandpaper to remove the enamel on the ends, and a toroid inductor (which is a toroid bead with one wire wound around it, which will be removed) or a round ferrite toroid (also called a toroid bead - it has no wires wound around it).
Youíll also need these other common items that you probably have lying around your home already to make the rest of the light-up Minecraft torch:
Step 2: Making the Inductor
If youíre using a common mode choke inductor (like the one from Digi-Key linked above), you can skip this step.
If youíre making the inductor using magnet wire and a toroid inductor that only has one wire wound around it, start by unwinding the wire on the toroid inductor. See the pictures in this step for how to do this. (If the inductor only has one wire wound around it, it will have two metal prongs - the inductor needed for this project must have two wires wound around it, giving it four metal prongs.) Once the wire is removed and you are left with the toroid bead, you can wind new magnet wire around the bead as described in the next part of this step.
If youíre making the inductor using magnet wire and a round ferrite toroid (that has no wire around it), start by cutting two lengths of magnet wire, each the same length and around 70 cm long. (If possible, use two different colors of magnet wire.) Twist 2 to 3 cm of the ends of the wires together. Next wind the wire around the toroid, through the opening in the middle and around the sides (leaving about 5 cm to 10 cm of wire "tail" with the ends twisted together). See the pictures for details. While you wind the toroid, do not let the wires overlap each other (keep the two wires side-by-side, and do not wind them over wire already wound on the toroid). Wind the toroid tightly until you get back to where you started winding it. (It doesnít matter how many loops you make exactly - in the pictures, you can see I made an inductor with 12 loops [paired], and later I re-did the wire on this toroid bead with higher gauge wire to get 14 loops on it, but thereís a lot of flexibility in what will make the circuit work.) Once at the beginning, cut all four wires so that they have around 5 cm of wire loose. Then use fine sandpaper or carefully use a sharp knife to remove the enamel coating on the last 1 cm of the wires.
Step 3: Making the Joule Thief
Brief overview of the circuit
As mentioned earlier, a joule thief is basically a relatively simple circuit that allows somebody to use "dead" batteries to power something that requires more voltage than the battery has left (it sacrifices current for increased voltage). In this Instructables project, a dead battery is used to power three yellow LEDs. Current first flows from the battery through one of the wires of the toroid inductor, which creates an electromagnetic field (EMF). From the toroid inductorís wire, the current then flows through the resistor and the transistor.
Transistors are basically like a type of switch, and when the current goes through the transistor (specifically to the base and out of the emitter), this causes the transistor to switch and let current go through the other wire of the toroid inductor (traveling specifically through the collector and emitter of the transistor). When the current goes through the other wire of the toroid inductor, it goes through the wire in the opposite direction compared to the first wire, which means the EMFs made in the two wires oppose each other. This opposition decreases the current and causes the transistor to switch, again only allowing current to go through the original wire in the toroid (to the transistorís base and out the emitter). But then this switches on the other path in the transistor (allowing current to flow in the collector and out the emitter), which switches itself off due to the opposing EMFs in the toroid, etc. This whole process causes the circuit to oscillate, which generates a higher voltage (at the expense of current) and powers the LEDs.
Assembling the circuit
The order in which you assemble the circuit doesnít really matter (although itís best to attach the battery last since itís hard to know what the off position of the switch is). Here Iíll walk through assembling the circuit based on the order shown in the pictures above. This breadboard doesnít have labeled holes, but, holding the breadboard so that the dividing groove goes up and down, I will refer to the columns as A-J (going from left to right, continuing across the groove) and the rows as numbered 1-17 (going from top to bottom). (Note that it doesnít matter which end is "top" - it works either way.)
For those of you who like that kind of stuff, I've included an oscilloscope image of the circuit (it's the last picture in this step) -- it was taken from collector to emitter. Enjoy the pretty square wave!
If the LEDs donít light up when you turn on the circuit, there are some things you can try:
Step 4: Making the Torchís Flame
I specially made a torch flame for this Instructable that includes the top part of the torchís flame - you can see this top part in the game, but Iíve never seen it in a real-life version of the torch, and I wanted to include it.
Print it out
To make the torch flame, start by printing the torch flame PDF in this step. Refer to the arrows for how to fold the different parts together as you go through this step.
Cut it out
Cut the out the flame from the print-out, making sure to leave the white tabs (theyíll be used for gluing). You can cut out the hand-drawn arrows and refer to them in the PDF itself. Take your time carefully cutting everything else.
Fold the four separate sides of the flame, as shown in the pictures. Then fold each of the white tabs backwards, towards the interior of the flame (except for the four tabs on the bottom - leave those unfolded). Next fold the sides of the flame faces to give them ridges - see the pictures for where to do this folding.
Once youíve folded it into the right shapes, and can see how the sides will be attached to each other, start carefully gluing it together (using the tabs). Start with a face on one end and work your way around the sides of the flame to the other end. Look at the arrows in the PDF and the pictures to see how to glue everything together using the tabs. I recommend using a toothpick to reach those hard-to-reach crevices with glue. Do not glue the tabs on the bottom.
Step 5: Making the Torchís Wooden Base
The folding for this is much easier than making the torchís flame, so enjoy!
Print it out
To make the torchís wooden base, start by printing the PDF in this step. (The bottom square will cover the underside of the bottom of the wood base.)
Cut it out
Cut out the wooden base from the print-out, making sure to leave the white tabs (theyíll be used for gluing). Then cut out a small flap, which will be how you can access the inside of the torch - this is the edge that does not have a white tab (see the pictures).
Fold between the four separate sides of the wood base, as shown in the pictures. Then fold each of the white tabs backwards, towards the interior of the wooden base.
Making the cardboard interior
On a piece of cardboard, use a ruler and pen or pencil to make two long lines that are 18.25 cm apart. Between these lines, and going perpendicular to them, make five lines that are spaced 4.06 cm apart from each other. See the pictures for details. Using the utility knife (so you get clean cuts) and ruler, cut out the large rectangle that encompasses the lines. Then, along the lines that are 4.06 cm apart, use the utility knife and ruler to cut the lines, but not all the way - leave the back side of the cardboard intact.
Youíll next want to cut a small flap which will be how you can access the inside of the torch. On the wood base print-out, this is the edge that does not have a white tab - you can lay the print out on top of the cardboard to see where the flap will end up. To make the access flap, you should go to one of the edge sides of the cardboard and cut a line across the side that is 2.25 cm from the top, and then another line 9.2 cm from the top - see the pictures for details. Cut all the way through the cardboard.
Making the latch
You can make a simple latch that seals the cardboard flap shut. To do this, take a paperclip, unfold it and cut off part of it as shown in the pictures above. Then orient the cut-up paperclip so that the cut part goes down into an open groove of the cardboard, and the rounded part sticks out through the edge of the cardboard. Use a knife to open part of the edge of the cardboard so the rounded part of the paperclip can easily slide up and down inside the cardboard flap. Then slide the paperclip into place as you planned - when the paperclip is up, the flap is "unlocked," and when the paperclip slides down, it should go into the groove on the bottom part of the cardboard, "locking" the flap shut in place.
Step 6: Attaching the Joule Thief Circuit
Youíll next attach the breadboard and battery pack to the inside of the cardboard frame you just made. You can use epoxy or super glue (with adult supervision) to attach the circuit to the cardboard, or, if you want to be able to remove the circuit at some point, you can use adhesive-backed Velcro to attach the circuit. Because I want to be able to remove the circuit, I used adhesive-backed Velcro.
Open up the cardboard frame so you are looking at the interior side. Where you made the access flap, attach the battery case to the cardboard. This will make it easy to open the torch and access/replace the battery when needed. Then, next to the battery case (on the left), attach the breadboard in place. Make sure that the LEDs are pointing up, that the parts are positioned so that you can completely close the flap (without bumping the switch, etc.), and that you can easily access the switch when you just open the flap from the outside.
Tip: Check again to make sure the joule thief still works, lighting up the LEDs, since youíve been moving it around a lot! There could be some loose connections that need to be fixed.
Step 7: Attaching the Print-Outs to the Cardboard
Fold the cardboard into its torch shape (with the four sides coming together) and place a few pieces of tape on the inside to hold the sides together while you glue on the paper exterior. Then attach the flame to the top of the torch. Carefully line a thin layer of glue on the inside of the four bottom white tabs, and then lay it over the top of the cardboard frame - it should nicely fit around the cardboard. Hold it on the cardboard a moment to let them glue together.
Then figure out how the wooden base print-out will fit around the cardboard frame. Identify where the access flap will go. (The square sticking out on the base print-out should cover the bottom of the torch.) Glue the print-out on the access flap first because it is most important that this part is lined up correctly. Then glue the rest of the wooden base print-out on the cardboard (using a thin layer of glue) - make sure to glue the tabs for the bottom square before gluing the sides around it.
Step 8: Enjoy Your Light-Up Joule Thief-Based Minecraft Torch!
Enjoy showing off your Minecraft torch! You can carry it around with other Minecraft gear, or use it as a "green" nightlight, reusing all of your "dead" batteries. Enjoy its warm yellow glow, and be happy that it keeps monsters from spawning nearby!