Circuit Making: the Modules

This activity has received funding from the European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framwork Programme for Research and Innovation.

Circuit Making is a tinkering activity that has been developed in order to allow kids to have a fun and educational first encounter with electrical circuits.

Muse Fablab has developed a set of 8 magnetic modules that can be used both in the context of a formal lecture, and in a playful tinkering setting.

This instructable will guide you though the process of reproducing those modules, as well as the additional materials that are used when experimenting with the electrical circuits.

Step 1: Get to Know the Modules

The modules you are going to build belong to three categories: power supply, input and output.

The power supply module is called 9 Volt Battery. You will use it to power your circuits.

The input modules are called Button, Switch, LDR Sensor and Potentiometer.

Button and Switch will be used to turn the circuit on and off. The first works only as long as it is pushed, whereas the latter is designed to stay in position until it is changed back to the initial state.

LDR Sensor and Potentiometer are two different kinds of variable resistors. The amount of resistance, in the first instance, is proportional to the amount of light that is placed upon the sensor. In the second instance, the amount of resistance is controlled by turning the shaft clockwise or counterclockwise.

The output modules are called LED, Buzzer and RGB LED.

LED and RGB LED are visual outputs. The first one is similar to a simple light bulb. The second one is a little bit more complex, since it contains three different lights that can be turned on and off individually.

Buzzer is an output that produces a high pitched sound.

Step 2: Cut the Structures of Your Modules

The Circuit Making modules can be easily reproduced using a laser cutter.

Start off by downloading the "modules" PDF file. By feeding it to the laser cutter, you will obtain the foundation of a complete set of modules.

We suggest using plywood or plexiglass. Plywood is cheaper, but comes only in one color. On the other hand, plexiglass will allow you to differentiate the modules by category.

In order to built each module, you will also need a bunch of other components, including screws and magnets, that are listed in the Circuit Making Bill of Materials. You should be able to find all of them at your local hardware store. Once you're all set, you can start building.

Step 3: Building "9V Battery" and "Buzzer"

Let's start off with the module called 9V Battery.

Each module includes a set of legs made out the following items:

• 1 magnet
• 1 screw
• 2 or 3 washers
• 1 nut

First, insert the screw in the hole of the magnet. Since the magnet is countersunk, the screw head should fit perfectly. Then, repeat the action with the 2 washers. Later, you will need the nut to secure the leg to the module.

Now it's time to loosely attach the legs to the base of 9V Battery. Notice that the top of the base has the name of the module written on it, as well as the plus and the minus signs. Insert the screws in the two holes of the base, making sure that the engraving sits on the top. This will help you identify the positive and the negative pole of the module.

Keep the legs in position using the nuts. At this stage, you don't need to tighten them; just make sure they don't fall off.

Once you've built the 2 legs needed for 9V Battery and loosely attacched them to the base, strip the wires of the 9V clip. If you don't have a wire stripper, feel free do use regular scissors.

Each wire will be wrapped around one of the screws. The red one should be wrapped around the one marked with the positive sign, whereas the black one should be attached to the one marked with the negative sign. In order to do so, insert them in the small holes of the base, making sure they stick out on the top. Divide each set of wires into two bunches and roll them until they are firmly attached to each screw. This passage is very important for the effectiveness of the circuits you will make later: if they aren't attached properly, there won't be the needed electrical connections.

Once you're done with this task, tighten the nuts on the screws.

N.B. Repeat this building process for the Buzzer module.

Step 4: Building "Button" and "Potentiometer"

Now it's time to build Button. Start off by putting together two legs, as shown in the previous passage, and loosely attaching them to the Button base. Once you've done that, grab a small piece of copper wire and attach it to one of the four legs of the actual button. Repeat the action for the leg that sits opposite to the one you've just attached the wire to.
Place the button on the base. The holes at the center will help you to secure it.
Now take the two pieces of copper wire and wrap them tightly around each screw. Secure them with the nuts. Bear in mind that the buttons don't need to be oriented in a specific way in order for them to work.

Now let's move on to Potentiometer. The building process in quite similar the one you've just completed. Build the legs (which are three, this time) and loosely attach them to the base.
Take a look at the potentiometer. As you can see, there are three pins that need to the connected the actual legs of the module. The one at the center will connect to the leg marked by the letter S. The right one will go to the right leg and the left one will go the left leg.
In order to do that, use copper wire. You can wrap it very tightly around the extremities of the wires, or you could also solder them, if you have access to a soldering iron.

Step 5: Building "Switch"

Now let's build the switch module. First of all, build the legs.

Once you're done, take a look at your switch. As you can see, it has three different pins. You are only going to use two of them. Take two pieces of copper wire and attach them to two pins, as shown in the pictures. Bear in mind that there shouldn't be any connections between the pins, so make sure the wires don't touch each other.

Now insert the top of the switch inside the biggest hole on the base. Then insert the copper wires in the two remaining holes and fasten them to the screws.

Step 6: Building "LDR", "LED", and "RGB LED"

The remaining three modules are called LDR, LED and RGB LED. The first two have two legs, whereas the third has four of them. Even though they look different, their building process is quite similar.

Let's start with the LDR. Mount the photoresistor on the base, then bend its legs upwards, inserting them in the small hole of the base. The photoresistor isn't polarized, so you don't need to worry about placing it incorrectly. Now take two pieces of copper wire and wrap them around the legs. Secure the module with the nuts.

Now let's build the LED. The LED is polarized. The longer pin is the positive one, and thus should be placed on the side of the base that is marked with "+". Create the connection between the pin and the screw with copper wire.
The shorter pin the negative one. Connect it to one side of the resistor and use it to create a bridge with the screw that will represent the negative side of the base. You don't need copper wire for this side of the module.

The building process for RGB LED is quite similar to that of LED. Take a look at the RGB LED. The longest pin is the negative one, so you should connect it accordingly to. The remaning pins need to be connected to three different resistors and then to the appropriate leg. In order to avoid any mistakes, take a look at the RGB LED datasheet or simply test it by connecting each pin to a 9v battery, through a 470 ohm resistor.

Step 7: Making Your Pad and Pinwheel

In order to start tinkering, you will need a couple of extra elements.

First of all, a metal pad ("metal_pad.pdf") that will help you keep the modules in place. You can print our model and use it to enclose a metal sheet.

Secondly, a paper pinwheel (pinwheel.pdf"). Once you've printed it, paint the dots using conductive ink or use aluminium foil to make them conductive. This will later be helpful when tinkering with the RGB LED module. Aluminium foil stripes will also be used to create connections between the modules.

Step 8: You're All Set!

Now that you've build all the modules and the accessory material, you can finally start tinkering.

If you're interested in reading about and trying out some cool excercises to discover how basic circuits work, check out the instructable Circuit Making: The Workshop.

Enjoy!

Words by Margherita Ferrari, MUSE FabLab

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