Code snippets, ideas and events from IT related projects

Abstract

There is more and more small of devices around us, like phones or mp3 players and as any other they needs batteries or other power supplies. It can be problematic if you don't have money for new batteries and you don't have charger - basically this what was my problem with mp3 player.

Interesting solution in its case may be power supply based on power of muscles. You just push or roll something and this creates power needed for the player. In this note I would like to present prototype of such device.

It works!

I was inspired by flashlight presented in 'Elektronika dla Wszystkich', with is a polish electronic magazine. They used step motor as en element that creates voltage. Those motors can by bought in electronic shops or detached from printers.

If you roll motor faster you get higher voltage, if it's to high, then your player will be damaged. This is why we need additional circuit between motor and player, you can see it at bellow image.

I've used 16V capacitor and I think that step motor won't produce higher voltage, so it's safe (under higher, that maximal voltage capacitor may explode). Diodes and resistor at the output protects against too high voltage. I used regular, cheap diodes.

If you will need higher output voltage, then you may use Zener diode instead/

Below are couple of pictures of my model.

Device is working as supposed and after modifications I'm going to use it in real life. I'm going to make solid cover and plug, that can imitate 1.5V battery.

Conclusion

It's amazing how how ordinary parts can be hacked together to create something new.