This is a project of a simple flashlight without battery, which turns on a LED, spinning an electric motor with the hands.
The operation is very simple, an DC electric motor (M) which works as a generator. When turning motor shaft with your own hands, electric energy is stored on capacitor (C) and the former turn on the LED, while resistor (R) limits current to the LED, avoiding its burn. Since the electrolytic capacitor has polarity, a diode (D) was put so that the current can flow only in one direction.
Material list:
- DC electric motor.
- 1N4007 diode.
- Electrolytic capacitor 6800μF x 25V.
- 470Ω resistor.
- High-brightness white LED.
- Terminal bridge.
- Wires.
The flashlight’s case is made of PLA and 3D printed. I choose the fluorescent blue color, so can see it in the dark.
The video below shows construction and test.
