Looking to build a battery powered small light (LED?) that works on a winding/pull cord. Alight until cord winds up.

I'm an assemblage artist and I'd love to begin putting electrical components into my art pieces. My first idea is to back light a piece with a small lamp which the user has to pull a cord to turn on, and then only lasts a short time (20 seconds?). This would need to run on a battery of some sort which could be changed when it's dead.

Can anyone point me in the right direction? I know VERY little about wiring/electrical -  only enough to rewire traditional lamps or light switches in the home.

Thanks so much!

elabz5 years ago
I would also make the pull cord wind a generator that would charge a capacitor that would then power the LED. I don't know about 20 seconds from one pull but you can definitely get a few seconds (or make them pull more than once) - check out the hand-cranked LED flashlights. You may be able to re-purpose one of them.

They are ubiquitous these days. I had a certain charity send me two of those as free gifts so far in their requests for donations. They are also pretty popular as corporate swag items. If you can't find a free hand-cranked LED flashlight out there, I'm pretty sure you can get one for couple bucks in a discount store.

This way you'd need no battery and no turn-off control circuit either. It'll just go out when the charge is gone.

Good luck with your project!
pickwicks_plum (author)  elabz5 years ago
Oh great minds think alike! I just ordered two different types online to see if I could retro fit them for my purpose! If I success, I will post a photo! :-) Thanks so much!
You'll probably want to use a micro controller to run the setup. When your cord is pulled it can hit a small switch telling the micro controller to turn on the lights and keep them on for a pre set amount of time.

The Arduino is a nice simple platform to start with. You should be able to find a wiring diagram and code that has already been done that will work for your project.
pickwicks_plum (author)  mpilchfamily5 years ago
Thank you! I will check it out!