Did you know that the first flashlight, developed by Conrad Hubert in the 1890s, was almost exactly like the one you’re going to make in this experiment?
Materials you will need:
- 2 Energizer Max® D cell batteries (separate batteries—you won't use your Power Pack for this experiment)
- Number 22 insulated copper bell wire
- Cardboard tube (paper towel) cut to 5.125" in length
- 3-volt flashlight bulb
- 2 brass fasteners (brads)
- Small cardboard piece for holding bulb
- Paper clip
- Electrical Tape
- Bathroom-size paper cup
How to Build the Flashlight:
- 1. Cut the cardboard tube lengthwise and flatten. Insert the two brass fasteners with the paper clip attached to one of the fasteners.
- 2. Cut two wires and strip both ends. Attach one wire to each fastener and cover with electrical tape.
- 3. Cut a small cardboard piece to fit over the top of the tube. Make a hole in the center of the cardboard piece and insert the light bulb.
- 4. Wrap one of the wires around the body of the light bulb.
- 5. Connect the D size cells so that they are in series and use electrical tape to secure them together. Place the cells in the cardboard tube, wrap the tube around the cells, and use tape to secure it.
- 6. Use tape to secure the light bulb assembly to the top of the tube, make sure the bulb makes contact with the positive battery terminal.
- 7. Secure the wire on the other side of the tube to the negative battery terminal using electrical tape.
- 8. Cut a hole in the bottom of the paper cup and use tape to secure it over the lightbulb on the top of the flashlight.
- 9. You now have a working flashlight. Closing the paperclip switch allows current to flow through the circuit and light up the bulb.
Building this flashlight has given you an example of one of the most important uses of portable electrical power.