Unconventional Switch: Pencil Sharpener Light - by Thu Pham & Peter Ochoa

This switch design utilizes a pencil and pencil sharpener to create an unconventional, interactive way to control an LED. The 5V power source from the Circuit Playground flows through two 100-ohm resistors in series, creating a total resistance of 200 ohms, and powers a 2V yellow LED. The switch is formed by attaching one alligator clip to the pencil’s tip (graphite) and another to the metal sharpener. When the pencil is inserted into the sharpener, the graphite completes the circuit, causing the LED to light up. 

This design creatively explores the conductive properties of everyday materials like graphite and metal, turning a familiar object into a functional switch. Beyond a simple on-off mechanism, the concept embodies a playful interaction between user and object, transforming the act of sharpening a pencil into a moment of discovery and illumination. It also highlights the often-overlooked conductive potential of common materials, making the switch both functional and surprising.