For this project, you'll build a switch that allows you to control the flow of electricity. This switch can then be used in the other experiments.
Materials You Will Need:
- Energizer® Power Pack
- Spring-tension wood or plastic clothespin
- Number 22 insulated copper bell wire (three 10" pieces with 1" of insulation stripped off both ends of all wires)
- Small blocks of wood
- One drywall nail, thumbtacks, paper clip
- 3-volt flashlight bulb
Please Read Carefully!
All experiments use safe, low-voltage battery power. Household electrical current contains high voltage that could cause serious injury. DO NOT use household electrical current for any of these experiments. ALL experiments should be conducted under adult supervision.
- Carefully follow wiring instructions for each experiment - improper wiring can result in battery leakage and/or rupture.
- DO NOT take a battery apart - contact with internal battery material can cause injury.
- DO NOT dispose in fire, recharge, put in backwards, mix with used or other battery types - may explode, leak and cause personal injury.
How to Build a Switch:
- Wind a bare wire end around a thumbtack. Hook a paperclip around the tack and press it into a wood block.
- Wind the second bare wire end around another thumbtack and press it into the wood.
- This wire will connect to your Energizer® Power Pack positive (+) lead wire.
- Place a third thumbtack in the middle of the wood block to hold your paper clip switch in place. Your switch is now completed.
Alternate: Insulated knife blade switches are available commercially, and are used to illustrate the experiments throughout this site.
How to Build a Bulb Holder:
- Nail a clothespin to a wood block.
- Place a loose wire from switch (step #1) with a tack into the wood directly under the clothespin jaws.
- Wrap one stripped end of the remaining unconnected wire around the bulb. Clamp it in the jaws of the clothespin with thumbtack below in order to make a complete circuit.
- Tack the loose wire to the wood. This wire will connect to your Energizer® Power Pack negative (-) lead wire.
Alternate: Insulated light bulb holders are available commercially, and are used to illustrate the experiments throughout this site.
How to Complete the Simple Circuit:
- Take wire from "How to Build a Switch" step 3 and bend stripped end at right angle. Connect wire to positive (+) lead of your Energizer® Power Pack with tape.
- Take wire from "How to Build a Bulb Holder" step 3 and bend stripped end at right angle. Connect write to negative (-) lead of your Energizer® Power Pack with tape.
When the circuit switch is open, the current does not flow to the bulb. With your finger, press down on the paper clip switch. You are closing and completing the circuit so the electricity can flow to the bulb.
The switch, bulb holder, and portable power are a complete circuit and arrangement of conductors; they allow the passage of electric current through the wire. Metal objects make the best conductors. Copper, brass, steel, or a strip of tin can have many free electrons capable of being moved along by an electromotive force such as voltage from the battery. In insulators, such as the wire covering, electrons do not move easily, so you can work with electricity safely.