Remember this vintage toy, the top that doesn’t stop spinning?
Let’s do a little upgrade this time, by adding something that can make the top spin like crazy, and emits eye-catching light.
Use LC resonant circuit to produce high frequency(a few MHz) electromagnetic waves, pick up the energy with another LC circuit, and transfer it to light up the LEDs, to make a self-luminous non-stop top.
Bill of materials:
0.5 mm magnet wire, 10 meters long
A 2N3904 transistor
A blue and a green LED
A 104 capacitor
Closely wind a 5 cm wide cylinder with magnet wire for 30 rounds, at the 15th round, connect it to the 1.5 v battery anode, and solder it according to the circuit diagram. Connect the anodes and cathodes of both LEDs to each other, and solder it to the magnet wire that’s closely wound in 3 cm for 30 rounds. Fasten it to the bottom of the top with hot glue.
Lastly, fasten both circuits to the bottom of a pudding cup with hot glue, and it’s done!