Week 2 | Electronics: Connecting Materials

First some theory

Before I started working, I got a lot of information in the tutorial given in the lessons. Below I have summarized what I have taken from this in my process.

Circuits

To work with electromagnets, I first need to know how a circuit works. An electrical circuit is a path or line through which an electrical current flows. There are three types of circuits:

Proper circuits When using a voltage source we add what is known as a ”load” to the circuit. This can be LED’s, resistors, etc. Basically anything that will cause a voltage drop because the electrical current wants to ﬂow from a higher voltage to a lower voltage.

Short circuits If no load is present in the circuit, it's a short circuit. This is dangerous, because there is nothing to restrict the current flow, and you can end up with burned wires, damage to the voltage source or a quickly-drained (or exploded!) battery.

Broken circuits This is an open or broken circuit, which is a circuit that is incomplete. Although not dangerous like the short circuit, it will ultimately fail to work because voltage can’t reach the components.

Kirchoff's Law

Kirchhoff's Law says the following: The voltage drop across the resistor, in addition to the forward voltage drop of the LED always equals the supply voltage (when in series). So, all the voltage generated is and should be used up by components in the circuit energy build-up, or unlimited current flow produces heat to release the excess energy (Kirchoff’s Voltage Law). Also, Current is the same across the entire circuit (Kirchoff’s Current Law).

Ohm's Law

In short, Ohm's law is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit. The formula is as follows: V=I*R. Voltage is the difference in electric potential between two points, current is rate at which electric charge flows and resistance is the ****measure of a material’s ability to block electric current.

Some other, basic things I learned about electricity, is that electricity always flows from + to -. Also, electricity follows the path of least resistance, conductive materials allow electricity to flow and resistive materials allow electricity to flow, but with a smaller current. Source: https://learn.sparkfun.com/tutorials/voltage-current-resistance-and-ohms-law & lessons in class

Paper circuits

Before we start working on the main assignment: the DIY speaker, we first got some simple assignments that made us understand the basics of how electromagnets work. With every exercise, the intention was to conduct electricity and turn on a light.

Everyone has received an a5 page with the instructions of the assignment. This same page also shows exactly which elements you need and where they should be placed. You can paste the elements exactly on the image on the page and assemble them.

To make the circuit work, I had to be sure that the circuit would be a loop, so that the electrodes can flow from Anode (+) to Cathode (-). This is called a current. Only the components that are connected in the loop are functional. Important thing to keep in mind that electricity will flow through the path of least resistance. An unintended connection between the + and the - can lead to a short circuit.

LED & KVL

The first paper circuit worked quite simple. With the example printed on the paper, I prepared a battery of 3 volt electricity, an LED light, copper tape and a resistor. The resistor is necessary to prevent the LED from burning out.

Dimmer & Ohm's Law

The second assignment is a little bit different. Also here, I use copper tape, a resistor, a 3 volt battery and an LED light. Only a velostat has been added here. The assignment is to make a dimmer light. The harder you press, the brighter the light should shine. We will do that by adding a material with variable resistance (a pressure sensitive material called Velostat).

By pressing the sheet of pressure sensitive material, conductive particles come closer together, so more current can flow through. Velostat is a plastic combined with carbon and can be found in electronics packaging material. After placing the copper tape and components unto the circuit I cut the line with a scissor so that I can fold the flap. Then, I place the piece of velostat on top of the copper tape in the defined area. Now, I can close the flap and apply varying pressure by pinching and releasing the fold.

Parallel LED's and KVL

The last excersize was almost the same as the first one. For me, it was very easy and I had no troubles with it. The difference was that it's not one LED light that has to turn on, but two. In the first exersize I already turned two lights on so this was almost the same but then with some space between them. Unfortunatley, I lost the picture where I made this circuit, but here you can see how it worked.

The Assignment: A DIY speaker

For this duo-assignment, I will develop, together with my compagnon, a DIY soft speaker by designing and fabricating a coil (out of copper wire, copper tape, conductive textile and/or conductive thread) and a membrane (out of paper, textile, other).

Together we will solder an amplifier and a hacked jack connector and learn how to connect a speaker circuit and power it with a lab power supply.

The artist/engineer duo EJ Tech, Plusea (Hannah Perner-Wilson) and soft circuiteer Liza Stark started with this work and now, we are going to build upon their work and look for more ideas.

Learning goals this assigment:

Practicing Ohm’s law, experiment with different types of hot and cold soldering, and learn how to use a multimeter to test and debug electronic circuits.

Assembling the amplifier

I completed the assignment working together with Duncan.

First of all, we assembled the amplifier.

The amplifier consists of a few parts. A mono amp, where all the wires go to. A jack connector, which you can connect to a phone where music is played from. A crocodile clip cut through the middle, so that you have two and both you can attach to the coil. And finally a + and - wire that you can connect to a power supply.

We had to assemble the Jack connecter ourselves. This was not very difficult. In principle, you unscrew the connector, solder a + and - wire to it and screw it closed again. Where you should pay attention to here is that the two wires do not touch each other. Otherwise it could cause a short circuit. The - you fix in the ground of the mono-amp and the + you put in the +.

Last, I screw the crocodile clips into the mono-amp with an ultra thin screwdriver and so, the amplifier is ready to use.

After this we started designing the coils.

Coils

There are many options to design a good-working coil. We could use a conductive thread with a dot pattern design and embroider the coil onto membrane. We could use conductive iron-on textile or use copper sticker foil and the vinyl cutter. After seeing and discussing all our options, we thought about making something on textile. Why? Just to try something out.

Coil one

Our first idea was to create a braided design with copper sticker foil. In this way it should look like checkerboard . We tried this on denim. If it worked, the idea was to make it more neat.

Unfortunately, no Ohm went through this. We have tried a lot to make it work, but unfortunately without a positive result. The cupper tape did not conduct properly. Looking at some classmates, it turned out that this material didn't work for them either.

Before I came to the conclusion that it was on the tape, I first debugged the amplifier to see if it was due to another underlying problem. I did this with a multimeter. By testing different pieces of the circuit with this I found out that there was no conduction between a certain part that I soldered. Nothing had collided so it was strange, but I soldered this part together with Kaj with an already working example coil, I tested the amplifier again. Now sound came out so debugging was successful.

Then we came up with a completely different idea and we continued with it. Below I will tell you more about it.

Coil two

A week ago, we learned an interesting way of embroidery at the textile museum. We liked to apply this to the design. It is an ancient Japanese technique that is better known as Sashiko and was used to prevent wear.

The next day Duncan brought different types of textile with him. After looking at everything and discussing how we want our design, we chose the textile artificial leather. By making a hole in this artificial leather and sticking another fabric behind it, it is a good start to use Sashiko's technique.

Then, we had to find a good conductor, which will conduct enough Ohm. I saw a sort of thin copper wire that worked on other designs some classmates had. Because of the corona virus, I couldn't go back to the Makers Lab to find out what kind of wire it exectly was.

We made a design on Illustrator. With a laser cutter, we printed the design on the fabric and we began to embroider.

After the embroidery was in, we measured how many ohms went through the coil with a multimeter. Unfortunately this was only 0.8. We have come to the conclusion that if we want this coil to work, we have to embroider a few meters further. Unfortunately that did not work for us, because the design would be no longer as we envisioned.

That's how we started our 3rd and final design.

Coil three

This design has the quote "Less is more". Since Duncan and I had a comprehensive plan and idea in the first two, we came up with the idea to turn it around. First see what works and build on that. As a material I took a white, thin and soft feeling fabric. As a wire, I used a thinner copper wire with a good resistance because it's combined with a non-conductive wire. Also with this wire, I couldn't get the exact name of it because of the Corona virus.

The design is inspired by examples that the maker's lab offered to the students. The intention was that I would embroider a simple spiral in the fabric. After I made a round I decided to see how much Ohm went through this. I was positively surprised that this was more than enough for a working speaker. I tested the coil on the amplifier and sound did indeed come out. Mission accomplished. Less is more.

Electronics zine

The design

colors

After seeing some books, magazines and examples of color combinations in the Makers Lab, we ended up using only 1 color on each page instead of 2. With 1 color you can still make a lot of beautiful designs and it offers our classmates a nice challenge to try this out.

We have chosen to let our classmates choose between the colors red and orange.

paper

Because we only use one color, we did not like to do the color of the paper basic white. We have chosen to choose (light) blue for this background. Red or orange fits well with this. The combination gets a sense of electronics.

We also paid attention to the thickness of the paper. The cover is darker blue and has a thickness of 160 grams. The inside is a lighter blue with a weight of 120 grams. To make sure we had enough paper (because we wanted to make a zine for everyone), I bought some extra paper from the Stumpel near my house.

The printing

Everyone forwarded their individual zine pages to our mail. I took all the pdfs and put them in 1 pdf file. Desiree has now put them all on Illustrator.

Then I started sorting all the pages together with Desiree so that it will be printed well in one go. With an example zine that we had put together (see image below), we had put all the names in the right order on the right pages, we printed the zine pages on a normal printer and attached them together to create a nice example. We used this to put everything in right order in Illustrator. This was a precise job that required a lot of attention. Because we looked at it with 4 eyes, this went perfectly.

Then we opened the Illustrator file on the computer of the RISO printer. Unfortunately, this did not work as we wanted. We made a PDF file of the final format and started printing from the RISO printer.

After printing the first master, we had some struggles with putting it back in the printer in a good way when we started printing it on both sides. After a few tests we found the right way and we were able to print the entire zine.

The binding

We took the best prints from the drying rack, put them in order and folded them in the middle. We would have been better off folding this per page afterwards to make it more precise. After folding we put in two staples and the zine went under the book cutter.

With some explanation from the people who worked in the Makers Lab, we cut the zine straight. Now he was ready for the show and tell.

Note: We printed the zine about 30 times so that we could make the zine booklet for everyone. The prints are still unbound in the Makers Lab and we could not work on it anymore due to the Corona virus.