Hello, I recently remembered one video on the Internet, where one craftsman “set fire” to an LED from AA batteries using a coil of several turns and an activated carbon tablet. It looked impressive. Naturally, there was no clue to the trick. Although the solution is quite easy to read. So I decided to make a homemade product in 3 minutes.
1. First you need to clarify that a standard “finger” AA battery produces 1.5 volts. To power the LED, you need about a volt more. This can be demonstrated using a regulated voltage source:
2. Next, take an AA battery and cut off the film from the top for convenience. Not every battery can do this. It is possible not to cut it if it is difficult, but mechanically the final design will be somewhat more complicated:
3. Now you can demonstrate that the LED does not light directly from the battery. Naturally, because this is an LED, you need to demonstrate this in both polarities, explaining the reason:
4. Next, we need a piece of wire 30 centimeters. I took a regular copper cable 1.5 mm2 and freed one core from insulation:
5. From the resulting piece of copper wire we make a coil of any size. I wound it right over the battery:
6. We bend one of the ends of the coil and wrap it with electrical tape (necessarily blue) to the bare part of the battery:
7. Now it remains to bend the legs at the LED, observing the polarity and calculating the distance from the “+” battery contact to the LED by the size of the carbon tablet:
8. Everything is ready for the demonstration of the “miracle”. We put in a charcoal tablet, which closes the circuit. Then we change the tablet to a magnet. We demonstrate the “wonderful” glow of the LED:
9. Now is the time to “be smart”, tell about the oscillatory circuit, about the world anti-Ether conspiracy, etc. I won’t advise here, I think you can fantasize a lot:
10. And now the most important thing is to tell the essence. So that even thoughts about the “miracle” do not remain, because children definitely need to develop critical thinking. To tell that at least the battery and AA, but unusual, not 1.5 volts, but lithium 3.6. To do this, demonstrate the inscription on it, as well as the luminosity of the LED without any tablets, magnets and coils:
11. Be sure to show special joy if an attentive child points to point 3 in which we demonstrated the impossibility of the LED to glow directly from the battery. There are at least 2 options here: a dead battery and a faulty LED. I used the first option.
I offer 2 options: 1 – short with fun music, 2 – longer with explanations
Thank you for your attention. All the best!