Matchbox Microphone

The final assembled piece is shown in the photo and video.

Material required:

-Matchbox

- Headphones

-White glue

- Scissors

- AA battery

- Copper wires

- Pencil (2 dollars)

- Headphones

- Pliers

- Hardboard

- Insulated rubber tape

The box is light and small, extremely easy to carry.

By tapping on the little black match box, or speak to it, we are able to hear the sound by using the headphones.

For more alternatives, you can connect it to a loudspeaker, and simply by speaking to the black matchbox, your voice can be magnified.
Or
Can be used as a telephone, by simply switch to longer wires, so that you can hear the voice in another room while the other person is speaking to the matchbox.

Matchbox microphone testing result

In the first video, we tapped on the matchbox. You can also speak to it. Although you have to speak in a very loud voice, otherwise the no sound is able to be recorded.

The second video contains the sound we recorded by using smart phone.

Results, Problems and Reasons

1. Thin pencil lead -  unsuccessful
During the experiment with thin pencil lead, we had a  concern about the thinness of the lead would be a major cause of this failure. Unluckily, we have proved that we were right about our concern.  We thought, the main reason is the resistance of the electric conductor (pencil lead) is too large, which caused our experiment to fail.

2. Thick pencil lead - successful
After the recent failure experience, we had switched to a thick pencil lead. This time, our experiment had succeeded! The two videos above reflect our result.

3. Lemon as battery - unsuccessful
 With excitement, we moved on to build the lemon power generator. Unfortunately, the result was not as what we had predicted.  We could not hear any sound coming from the headphones.
In order to find out the reason that causes this problem, we did some scientific research. We found that the correct procedure to generate electricity from a lemon is to insert a piece of zinc metal and a piece of copper into the lemon, then connect with wires. But we did not insert any zinc metal. So this must by the part we had done wrong.

Matchbox microphone testing

Now, we have connected all the components together. Unfortunately, we don't have access to any high-tech loudspeaker. Therefore, we decided to use our headphones and hold them against the smart phone speaker. We will try to use the voice recorder on a smart phone to record the sound. If we successfully record the sound that comes from the headphones, our project will be considered as successful.

Let's get excited and test the result!

Construction five -lemon as a power generator

 

Vicky comes up with an idea of using lemon as a power generator to replace buttery, so that we can reduce the budget of the project, and being environmental friendly at the same time. 

 Back to the science class we took in high school, we had learned that electricity can be generated if you insert two pieces of metal into lemon and connect it with wires.

(More information on this concept will be linked below)

https://en.wikipedia.org/wiki/Lemon_battery

Next day, we will set everything up and test the result. Hopefully it will work as we expected, and if it is not, we are going to find reasons and make further adjustments.  

Construction part four- improvementation

Take experiences from last time, we were going to use thinker pencil leads. 

These pencils were purchased by Yinxin in a convince store and cost at 2 dollars(including tax).

We used a sharp knife to cut off the wood part of the pencil and carefully took out the thicker pencil lead. It was an excitement when we cut the pencil perfectly in half without breaking the lead.  

Since the lead is thick enough to afford the wires' weight. This time, we achieved successful connection between the copper wires and pencil leads without any damage.

Constructing part three - match box with thin pencil lead

We curved the copper wires into a smaller circle for connecting the pencil lead easily and prevent them from breaking away.

However, the process was not as successful as we have expected, because the pencil leads are too thin and weak that cannot afford the weight of the copper wires. 

As a result, we have wasted a lot of pencil lead in this building process. So we are considering about making some improvement by using a thicker pencil lead. 

Construction part two-headphones port

In this step of the project, we are going to repeat the process of the curving the wires. 

According to the video we watched on YouTube, the instructor attached copper wire to both the top end and the tip end of the headphone connector, and made sure the two wires do not touch. 

Now, with the instruction in mind, let's start on the process.

In considering of the headphone is double track, we need to connect both left and right track in order to make both speakers work. 

Therefore, we curved the wire as shown in the photo above, so that both tracks can be connected. This is the part that is going to be attached to the top end of headphone connector.

The photo above shows the part that is going to be placed at the tip end of the headphone connector.

Now let's put them together. And here comes the final result of our low-tech headphone port.