Rotary Switch and LED

Click on the arrow in each of the pictures below to see vedios of how kids did the project.

Materials for a Rotary Switch

For this science project you will need:
  • card stock (thin cardboard)
  • two fasteners
  • a paper clip
  • tape
  • scissors
  • LED (3 volt)
  • coin battery (CR 2032)

Make a Rotary Switch and a Simple Circuit

Here is how to make  a rotary switch and a circuit for the switch to control.  To make the circuit you will need the materials for the switch  and a LED and a coin battery.
  1. Push the two leads of the LED through the cardstock and bend them down in opposite directions so they don't toucn.
  2. Push each fastener through the cardstock,each close to one of the LED leads, and no further apart than the paperclip.
  3. Tape the long lead of the LED to the + side of the coin battery. Tape the LED lead / coin battery  to one leg of a fastener.
  4. Tape the short LED lead to one leg of the other fastener. 
  5. Slip the end of the paper clip around one fastener

How the Circuit Works

On the under side of the cardstock are these connections:
  1. Paper fastener #1 to minus ( -) side of coin battery,
  2. Plus (+) side of coin battery to long LED lead,
  3. Short LED lead to paper fastener #2.
When you connect one paper fastener to the other by the paper clip, you complete the circuit: LED Lights!

Any conductor that connects the  fasteners will make the LED light! To test if an object is a conductor,  place the object so it joins fastener #! to fastener #2. If the LED lights, the object is a conductor!