The eternal flashlight or Faraday's flashlight is the so-called flashlight with an alternative power source. That is, this flashlight does not require batteries or battery charging. To "ignite" it is necessary to shake it. In the flashlight itself is a generator and battery.
Let's first get acquainted with the factory lamp:
I tried to paint the design as much as possible. The bottom line is that a cylindrical permanent magnet hangs freely in the tube - the housing between the rubber stops or springs (where it is). And in the center of the tube a coil is wound. When shaking, the magnet runs up and down inside the coil, creating alternating electricity in it.
Further, this electricity enters the diode bridge and turns into constant and charges batteries with a voltage of 3 volts.
Let's see without a case.
We see a solenoid, a cylindrical magnet, limiters, a small board with diodes, a switch and batteries. Oh yes and the LED on the board.
Shaking the flashlight, turn it on. Works !
And here is our prototype:
Tick-out box. The tube on which the coil is wound is a body from a ballpoint pen. A couple of magnets from the hard drive, there are some. Yes, capacitors are used instead of batteries. White LED a couple of diodes.
Scheme. There is a feature of coil winding. As you probably noticed from the diagram - the coil consists of two windings, the total length of the coil is 40 mm. Share mentally hit. In the first half we wind 600 turns of the thinnest wire with a diameter of about 0.08 mm. And in the second half of 600 turns. That's all - two sectional coil is ready. Further according to the scheme. Do not forget about the limiters, so that the magnets repel and jump quickly.
And here is my more powerful sample. There is already used a coil with a large number of turns and three sectional magnet.
I wish you successful homemade products!