I will show you a way to make the LED glow without connecting wires to it. For this, it will be necessary to assemble a simple device on one transistor. And you can play friends by showing them your magical abilities.
Scheme
Schematic diagram on a single transistor. This is an almost classic high-frequency generator with inductor and feedback.
The inductor is a wire made in the form of a round loop. The LED also has a receiving loop. When combining these loops together at a certain distance - the energy is transmitted to the LED and it starts to glow.
The whole circuit is powered by finger batteries.
Perhaps the question is creeping in - where is the feedback in this generator? The generator operates at a very high radio frequency. And a capacitor for feedback is not required, so the transistor case itself has a small capacity. Plus, inductors are very close to each other.
Details for the circuit
Parts List:
1. Batteries - 6 pcs.
2. One red LED.
3. Transistor, type BF494 or similar.
4. The capacitor is 0.1 μF.
5. Resistor 33 kOhm.
6. Inductance 330 μG.
Wires, solder, etc. as needed.
For an inductor loop, any piece of a solid wire, not very thin.
LED itself
The LED will require further development. Its output must be bent into a ring and soldered. All. The receiving indicator of high-frequency radiation is ready.
Making a generator
It is very advisable to solder everything as I have in the picture.
I also collected two rings with an LED. One is red, the other is blue. So, just in case.
Connect the generator to a power source. And we bring the LED, if it is lit - everything works.
Next, check the distance, but which LED is working. It will be on the order of several centimeters.
Now it remains to fix the circuit and batteries under the table and amaze your friends with a fun and unusual gift. All the best!
