Week 8 – Birthday Switch


For this week’s assignment we were to create an unusual switch. Since it was one of my suitemates birthday, I decided to create a switch using a birthday blower. The idea was that it would open and hit a grounding wire and connect it to another grounding wire which would close the circuit consisting of three diodes in parallel.

The Circuit

The circuit was pretty straightforward to implement. Having taken A2 Level Physics, I still remember most of the content from Electricity and Circuits. Since voltage divides over elements (Three 2.0-2.4V diodes) in series, the 5.0V supply was not enough to run the circuit in series. Hence, I decided to connect them in parallel and maintain the same voltage across the different components. Below is the circuit diagram.

Figure 1. Circuit diagram

In order to connect the two grounding wires, I used copper wire/tape. By attaching the two ends of the grounding wires to a piece of double-sided tape, and appending the copper wire to the end of the birthday blower, I was able to close the circuit. The challenging part was aiming the end of the device such as to close the circuit properly. It took a few tries in order to get a hand of it, but I was ultimately able to aim it correctly and light up the diodes.


This was probably one of my favorite assignments in the class to date. It made me feel extremely happy when the diodes lit up, even though the circuit was bound to work. Unfortunately, one of the diodes was faulty and as I was setting everything up, I thought that the circuit was bad. After changing the diode, everything worked, but it was a good lesson on having patience (because I was honestly running out of it). It would have been more fun to mount the board and arduino on a wall so that I can stand properly while closing the circuit, but since everything worked out in the end, I was very pleased with this week’s assignment outcome.


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