Instructables
Picture of Improved Rechargable Torch
outside wing.jpg
IMG_5245.JPG
This is a hack for turning a fairly useless, dim, shake to recharge torch, into a torch which is bright, long lasting and can still be recharged but not just by shaking. This type of torch usually charges via shaking, and a magnet slides between two coils and charges a tiny three cell battery. The battery is small so it charges quickly while shaking, but needs almost continue shaking to maintain brightness, this is a bit of a pain.
What i did is i took the torch apart and rewired it with a bigger battery for both more brightness and more storage, the three LED's i wired all in parallel and a re-did the circuit board as it didn't have a diode between the coils and the battery, which meant some power was going back into the coils.

Because of the bigger battery it would take longer to charge so i made an adaption so it can be charges by either, shaking, like previously, the movement of a tree branch in the wind, or a fluttering wind generator. These all work by pulling the magnet up and down via a string, so almost any movement could be harness, like the turbulent flow of a stream or flapping of a flag.

I found the best way to charge this, is to clip the string to one corner of a t-shirt on your washing line when you are camping, the flapping of your clothing creates plenty of up and down movement to charge your torch.
 
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Step 1: Tools and materials required.

Picture of Tools and materials required.
Tools:

  • Soldering Iron and Solder
  • Hacksaw
  • Craft Knife
  • hot glue gun

Materials:

  • One shake to recharge torch
  • A old cordless phone battery
  • Small piece of strip board
  • some nylon string
For wing
  • Balsa sheet
  • tooth picks
  • paint

Step 2: Taking the old torch apart

Taking apart the old torch was easy. Un-screw then lens cap and all the insides out, do not amage anything or throw anyhing away as we use most of it.
willnate6 months ago
you should make it so you can charge it via wallwart
MrE9 months ago
Something doesn't sit right with me here. From what I seen of these circuits and the ones that I have owned there is no batteries. There is a capacitor that charges using an induction circuit. In all the ones that I have the capacitor can sometimes go bad but these are very low voltage led's on these. Hence the reason for the charging circuit. The only ones that I have seen that had batteries were these cheapy dollar store ones from about 8 years ago. The box said shake light on them but they were fake shakes. The magnet inside was a slug of metal and the coils inside were maybe 20 turns of wire that connected to nothing. On the circuit board was a cr2032 battery that would go out after a while and was soldered in so it looked real but there was nothing to the circuit. I am aware yours looks nothing like those but I very curious about those parts you pulled off.
benmurton (author)  MrE9 months ago
Yes i have seen a lot of torches like that! This one definitely has a battery. It has a three cell 40mAh NI-MH battery at 3.6v. The LED's are standard super bright one, not special low voltage ones. The generator part of the torch is really good, I don't know how many winds of wire it has but it is a very powerful neodymium magnet and the coils put out a good a decent amount of power for the size. The only other components were a switch, two bridge rectifiers which converted the AC electricity from the coils to DC current for the battery and three diodes which allowed either one LED or all three to be turned on. I basically kept the circuit how it was but got rid of the one or three LED switching and used the diode to stop current going back into the coils.