🌙 LED Nightlight
Build a cozy coin-cell nightlight with a paper lantern shade.
🧰 What you need
- 1–3 LEDs (any colour)
- 1 CR2032 coin-cell battery
- 1 coin-cell holder with a switch (or tape + a paper-clip switch)
- 1 small cardboard or paper cup
- Tracing paper or tissue paper
- Tape, markers, scissors
🔧 Let's build it!
- Check the LED: the long leg is + (anode), the short leg is − (cathode).
- Slide the coin cell into the holder with the + side facing up (the side with writing).
- Connect the LED's long leg to the holder's + wire and the short leg to the − wire. Twist or tape them firmly.
- Switch it on. Light! If not, flip the LED around.
- Decorate your paper cup: poke tiny star patterns with a pencil (with adult help), or draw on tracing paper and wrap it around the cup.
- Place the cup upside down over your LED. Turn off the room lights and enjoy your nightlight!
- Upgrade: add a second LED of a different colour, connecting it the same way side-by-side (in parallel).
🔬 What's happening?
LED stands for Light-Emitting Diode. A diode is a one-way street for electricity, which is why it only works one way round. When electrons cross a special boundary inside the LED, they release energy as light. Different materials make different colours! LEDs waste much less energy as heat than old bulbs, so a tiny coin cell can run one for many hours. Small coin cells can't push much current, which also keeps the LED safe without a resistor.