Turning on a light with batteries is a quick and easy process. You can also make a manual flashlight, or a temporary light source to use during a blackout. By connecting the batteries and the light bulb in the right way you create a working circuit. The electrons flow from the negative pole through the bulb and then return to the source through the positive pole; this continuous flow allows the light to stay on.
Steps
Method 1 of 2: With a Normal Light Bulb
Step 1. Gather the materials
You can use an ordinary light bulb or a small lamp; Also get some duct tape, although other types are fine as well.
- Type D battery.
- Insulated electrical cables (two pieces of 7-8cm).
- Light bulb.
- Insulating adhesive tape.
- Scissors.
Step 2. Strip the cables
Remove about 1.5 cm of insulation from each end of the cables; for this operation use scissors, being careful not to cut the internal copper wire.
Step 3. Connect the cable to the battery
Secure one end to the negative pole of the D-type battery using insulating tape.
Step 4. Join the bulb
Now that a cable is attached to the battery, take the other end and place it in contact with the metal part of the bulb. Do the same with the second cable, joining the stripped end to the metal edge at the base of the bulb; secure everything with adhesive tape.
Step 5. Close the circuit
Take the free end of the second wire (taking care that it is without a protective sheath) and put it in contact with the positive pole of the battery; as soon as the two surfaces touch, the light should come on. This is because the electrons flow from the negative to the positive pole creating a flow of energy that activates the light bulb.
Method 2 of 2: With an LED diode
Step 1. Get the materials
This flashlight is very simple to make and only has a couple of elements. Make sure the batteries are AA-size, as the high voltage quickly heats the cables, with potentially dangerous consequences.
- Insulated electrical cables (one 2-3cm piece and one 7-8cm second).
- Two AA batteries.
- One LED diode.
- Insulating adhesive tape.
- Scissors.
- Sheet of paper.
Step 2. Tape the batteries together
Align them so that the positive pole of one is in contact with the negative pole of the other. Use duct tape to keep them together; make sure they fit snugly together to avoid having to push them to establish an electrical connection.
Step 3. Strip the cable
Remove some of the insulation from both ends of the electrical wire to expose the copper core. For this operation use scissors and take care not to cut the inner portion; repeat the procedure for the second wire segment as well.
Step 4. Join the wire to the diode
Take the shorter segment and wrap it tightly around one end of the LED; proceed in the same way with the longer cable and attach it to the other end of the diode. Secure these contacts with insulating tape.
Step 5. Test the flashlight
Connect the second end of the short cable to the negative pole of the battery system. Without breaking this first contact, bring the free end of the longer cable to the positive pole of the power supply unit.
If the LED does not light up, reverse the contacts so that the short cable touches the positive pole and the long one touches the negative pole
Step 6. Unhook the cable
Once you find out which pole you need to attach the short cable to, unravel the end and join it to the correct battery terminal using adhesive tape; by doing so, you ensure a greater contact surface between the two elements.
Step 7. Wrap the batteries
Cut a sheet of paper according to the length of the power supply; roll the strip of paper around it, taking care that the cables remain inside the small torch. For now, the long cable does not need to be taped. Close the paper roll with the tape; the LED should stick out from one end of the "tube" and the long cable from the other.
Step 8. Use your finger as a switch
At this point you can take the loose end of the long wire and put it in contact with the battery pole; you will see that the LED lights up. You can hold the cable in place with your finger or use a piece of duct tape and this will keep the light on.
