Circuit Torch

This is a guide for assembling your Frank Lloyd Wright inspired Circuit Torch. One of our MSI Fab Lab ‘Take Home Projects’ you can also follow along with the video here Circuit Torch Video Guide

Before we start putting it together let’s lay out all our components, the parts that will make up our torch. This is called Knolling and it makes parts easier to find when we need them

Inside the kit you should find

1x Printed cardstock torch body

#1 or A1 & A2: 6" long narrow strip of Sparkfun copper tape

#2 or B: 1x 2" strip of wide copper tape (you can substitute 2 strips of sparkfun tape, as long as they overlap when stuck down side by side)

#3 or C: 1x ‘candle flicker’ LED

#4 or D: 2x 1/2" circular pieces of copper tape (you can substitute short strips of sparkfun copper tape)

#5 or E: 1x 1" circular piece of double-faced conductive tape

1x CR2032 Coin cell battery (individually packaged)

G 1x Glue dot (not marked on the old diagram, would be placed at the edge of the paper near the #1)

To start we will be applying the long thin strips of copper. Copper tape can be pretty tricky, but there are a few tips that make it a little bit easier to work with.

First, for an easier time peeling the backing, pinch one end of the tape with just a little bit sticking out and brush or flick the end of it with your fingertip up towards the copper side. After a few times, it should start to lift off the paper backing. But don’t peel it all the way just yet, if you peel it too quickly the copper will curl up like a ribbon and stick to itself (good for party balloons, but for our Circuit Torch, not so much…) instead, fold about half an inch of the paper back, so exposes some of the adhesive, this will make it easy to set in place.

Line it up with the end of the outline marked A1 or #1 and stick it down in the outline peeling and sticking the copper down a little bit at a time. Try to stay in the lines as much as you can but it doesn’t have to be absolutely perfect. Once it’s all stuck down, smooth or ‘Burnish’ it with your fingertip or the back of your nail so it’s well attached to the paper. Repeat the same process with A2 or the second #1

Now we can move on to the next step. Carefully peeling the backing off of the Short wide strip of copper tape, align it over the B or #2 outline, making sure it covers the end of A1. press it down firmly paying special attention to the spot where it overlaps the end of A1. We are using a special type of copper tape today; the sticky stuff on the back, which is called adhesive, has tiny little ‘nanoparticles’ of silver in it that make it ‘conductive’. So instead of having to solder our circuit together, we can simply overlap the different pieces of copper tape, and as long as they are touching, the electricity can pass through, and the circuit will work

Now let's get to know a little more about our LED. L. E. D. stands for Light Emitting Diode, and if we pick that apart, the first two words make sense, LED’s are Light Emitting, they light up, but the last word is really important in electronic terms, Diode means it’s a One Way Street for Electricity, it’s Polarized and only works if power is going through it in the right direction. This will mean that we need to set our LED up in the right direction if we want it to light up later

This is a ‘through hole’ component, which means it is made with long connectors that make it a little easier to work with. If we take a look at the wire leads or ‘legs’ coming down from the LED we can see that one of the legs is longer than the other, this is a clever way for the manufacturer to let us know that this leg is the positive or ‘Anode’ leg, the shorter leg is the negative or ‘Cathode’. I remember this because Cats often have a Negative opinion of electricity (and dogs, and water, and vacuum cleaners...) We want to separate these leads so that the positive Leg ‘kicks’ out and away from the negative, so let's take that longer leg and bend it out so it looks like the LED on our Diagram and then we can set it right on top of that picture so it matches up.

Time to make a ‘Circuit Sandwich’ (a robot’s favorite snack). We need to make sure that our LED stays put and that electricity can easily flow through our circuit. To do that we’ll use our two small circular pieces of copper tape to sandwich each of our LED’s legs onto the circuit. Peel the backing off of the first circle and use it to stick the leg of the LED down on top of A1’s Copper tape strip so that it is a sandwich of copper, LED leg, and copper again. We need to make sure that metal is touching metal here, and press the circles down really firmly with our fingertips. Electrons are super tiny and not very adventurous. Even the tiniest of gaps can seem like the Grand Canyon to them, so we need to make it easy for them to get where they need to go. We’ll do the same with the second small copper circle

Now we need to make a battery holder to hold our battery. For that, we’re going to use this larger circle of double faced copper tape. To start, we only need to peel the paper of on one side, then we are going to stick it down inside the #5 or E circle on the diagram, making sure that it overlaps the long strip of copper tape that crosses that circle, but also making sure that it does NOT touch the end of the copper tape in the #2 position.

Electrons are a little lazy, if the don't have to go to work, they won't, so you have to make sure there's no way they can get back to the battery without going to work (the LED) first... if one leg of the copper tape is touching the other before the led, it will let the electricity take a shortcut back to the battery, creating a Short-circuit.

Once we've carefully placed our battery holder in it's circle, like all the times before, we need to press the circle down really firmly with our fingertips. Once it is well stuck down, we can peel off the top cover to reveal the adhesive we're going to stick our battery to, on to the next step!

At this point you could just plop the battery down, but because this torch uses an LED, you would only have roughly a 50% chance of getting a working torch out of it, but we can dial that chance up to 100% by getting to know our battery and circuit better.

As we mentioned before, LEDs are polarized which means they are One-way, so let's get this circuit moving in the right direction by taking a closer look at our battery.

one side of our battery has a plus sign (+) on it, making that the positive side. the other is pretty much blank, that is the negative side

we want to make sure that that plus sign is facing up, then we want to center it over the copper circle we just placed and press it down firmly onto the adhesive. The battery should not be touching the 'L' shaped part of the circuit.

Our circuit is complete, but it can't light up yet. To do that we need to fold it in half along the dotted line. Our circuit should be folded inside the torch, and the colorful torch design is visible on the outside

We’ve just created something called an intermittent switch. This means that, like a button on a game controller, it only activates when you press on it. Pinch the two sides of the torch body together over the battery to light it up, and release to turn it off... Place the glue dot in the F position at the edge of the paper to hold it closed.

You've just completed your Circuit Torch!