Projects
key Log In or Register

 
 

www.flickr.com
tres frijoles' photos More of tres frijoles' photos
You are here: tearsoffire.org > Projects Web > GreenProjects > WindupFlashlight r13 - 22 Aug 2007 - 18:12 - ChristopherPepe
EditAttachPrintable

Start of topic | Skip to actions

WindupFlashlight

 



intro

generator + super brite LED = rechargable flashlight
flashlight_ortho.jpg handcrank rechargable flashlights are a great idea (not my idea - just a great idea). LED's comsume very little power compared to traditional blubs and last a lot longer. throw in the need to never change the batteries and it makes a simple yet elegant solution to the age old problem of the absence of light.

parts

flashlight_parts.jpg
  • recycled servo (gutted, basically a geared motor)
    • remove the servo control board
    • remove the hardstop in the gearbox (cut off with wire cutters)
  • 0.22F 5V capacitor
  • 10MCD superbright LED
  • blocking diode (standard LED, or any general purpose diode)
    • i used a LED for the blocking diode because it lights up when the current you generate flows through it. this is a satisfying reward as well as proof that the generator is working.

robot porn

flashlight_sch.jpg
  • it wouldn't hurt to put a small resistor between LED2 and GND to limit the current draw but isn't required.
  • the blocking diode blocks the energy you generated and stored in the cap from being used to turn the motor
    • experiment: wind up the flashlight (power switch off) and then short across the blocking diode - the motor will start to spin thus using up your energy
  • the bigger the cap the better (in F not size) but they leak badly above their rated values so a 4F 2.5V cap is no good. These LEDs are brighter with higher voltage

packaging

flashlight_assembled.jpg an important piece of the part selection is parts that will all fit in the servo case. there's quite a bit of room in there but you are still limited.

media

if you like this project let me know: cougarvt at gmail

-- ChristopherPepe - 06 Apr 2006

End of topic
Skip to actions | Back to top
Edit | Attach | Printable | Raw View | Backlinks: Web, All Webs | History: r13 < r12 < r11 < r10 < r9 | More topic actions
This site is powered by the TWiki collaboration platformCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding tearsoffire.org? Send feedback