Draw from the Well of Inspiration!

Coming up with a switch for an LED light naturally made me think of ideas, like the metaphorical light-bulb going off when you are struck by inspiration. I also wanted to create a switch that was interactive, ideally allowing creative input from the participants. Lo and behold - the "well of inspiration"!

It turns out this well is not so easy to draw from. I used conductive tape to make something of a well shape, and when you draw off of it the current will follow. The two ends of the switch are attached to the conductive tape and to the piece of graphite in the mechanical pencil. I learned that not all graphite conducts well, and the graphite of the mechanical pencils was most successful. When I tested it with the 1k resistor, it got dim relatively quickly. I wanted to get close to the lowest resistor I could use, but I also wanted a bit of a buffer since the amount of energy the LED would be getting would fluctuate a great deal depending on if the participant drew directly on the conductive tape or away from it (I also was getting different readings sometimes when measuring the voltage from the LED and the current so that made me wary as well).

Schematic with final measured numbers

Using R=(Vs-Vf)/I, I calculated the resistor needed to be about 106-118 (I was getting different readings for the Vf of the LED) for a current of 20mA (recommended from the video provided in Webcourses). I ended up going with 220 for aforementioned wariness reasons. The LED is marginally brighter with 220 than 1k, but aggressive and heavy handed drawing makes the biggest difference with brightness as you move away from the conductive tape.

Cross your fingers the graphite doesn't break on the way to class!

The Narrative: You, brilliant creator, have discovered the Well of Inspiration. Good job! You can draw from it, but the further you get the fainter the light of inspiration becomes. The light can be fickle, but with practice and hard work (and lots of graphite), you can move further from the well and maintain the light.

- CapriciousClockwinder2345620