Forever Dynamo Flashlight - GENNY!

[juiced]

Ok, so pretty simple.

  Take a generic Russian Dynamo Flashlight, they operate by pumping a lever which turns a flywheel with 2 * 1/2" x 1/4" magnets on it.

  I alwas wanted to convert a lightbulb into an emergancy charger/power source from this thing. I traveled for a very long time with them and they are absolutly indestructable. They even work 100% submersed in water!

   So today, i tried soldering a wire to a burnt bulb. It worked for several minutes, giving about 3.1w and than after securing the wires properly i got 5.08w!

  The solder didnt want to hold, probably for lack of flux; so i opened it up (yes they are even servicable! lol ) and soldered directly onto the coils output lines. I hollowed out a space between the two halves of the body and passed my wire through.

    Somehow im not getting the same power that i did before but its probable shoddy soldering on my behalf.

   My readings were:

          5.94 vac

           .532a

   &     9.117vac

          .558a

     To get the higher readings i had to really giver 'er! I guess in an emergancy you do what you have to though. I realised though, thats almost enough to power a small fluro!

    Why did i wait so long to do this? Because untill earlier this week i honestly didnt understand electricity (or remember anyways) enough to do the calculations and work. One small step forward.

   I think about 3 or maybe 4 of these gennies could fit in a bike hub... for those interested.

[ghurd]

I am impressed with that thing.

Maybe you could run it to a 1:2, or 1:3 transformer for 12vdc at a lower speed.

What kind of speed is the flywheel running?

G-

[Norm]

   Also what kind of magnets? probably not ceramic?

                   ( :>) Norm.

[juiced]

For speed... im really not good with RPM; yet.

  I disassembled one to try to make a pico-'bine; so i will try to get some pics up today.

   

[juiced]

Sorry, but i made a mistake.

  Its one ring NEO (i think). I must have been thinking about another toy i have.

   

[ghurd]

Something like the Hamster Genny?

G-

[johnlm]

I think this is what juiced is playing with.

http://www.nitro-pak.com/product_info.php/products_id/186

I saw several site with these - mostly survival / surpluse type places.  Most had these for $15 to $20 but this one is cheap, especially if it really puts out about 5 Watts.

[juiced]

Yeppers! I have some 200 or so of them. Just didnt want to sound like im advertising...

   That price is absolutly insanity! I feel like im ripping people off now! (i carry 'em @ 20$ CDN lol )

   Seriously guys, buy those up.

  I havent actually made a good contact and taken a reading yet, so that 5w is probably more of an average then maxium..

  And to think i was gonna send one out to Ghurd; when he can buy them cheaper than me! hahaha.... gotta love this business.

   Ok well, I had planned on making either a screw-in bulb/plug or as i have it a small wire out the back end.

 If you want to read a review on the durability of those lights, check out .. oh. sorry, nvrmnd.

[juiced]

After my excitment wore out, i had one remaining question.

  What could you actually do with 5W AC unless you have a really small converter to charge batteries with?

[ghurd]

I have 2... somewhere. And a couple chineeze too.

Took them far enough apart to add a giant cap, schottky diode, resistor and LED.

It worked pretty well. Size of a shoe box. Must have been the china ones, didn't get near that many watts. More like 1 watt. Was not impressed with the insides.

The prices on a lot of this kind of thing are way below cost. They are left over Y2K stuff that the stores are tired of counting. Sold like popcorn before, can't give them away now.  (I wonder when all those Y2K generators are going to be garage saled for $20?)

G-

[johnlm]

What can you do with 5W ac? (assume 5 VAC @ 1A)

Obviously make a flashligh.

Rectify it and charge your cell phone battery in an emergency - they already make a version of these hand jobs to do that.

Run it thru a transformer as someone suggested to get 12V and pump up your car battery after you leave the lights on and run it down,,ha ha.

[juiced]

  There is also videos of the light in action, hooked to a multimeter but i think maybe Admin here doesnt want it on thier bandwidth.

[GeoJohn]

Hey Juiced,

I will guarantee that those survival flashlights don't give off a whole lot of power, way less than 5 watts. Please correct me if I am wrong but when you took the voltage and current readings from the light you had only one meter and no light bulb in the circuit. When you measured the voltage you were actually reading the open circuit voltage and when you were measuring the current you were measuring the short circuit current.

It's hard to get a accurate power reading but here is how it is done. Get two meters, the flashlight and a working light bulb. Wire one terminal of the light bulb to the flashlight and through the ammeter back to the flashlight. You want to read the current THROUGH the light bulb. Then read the voltage ACROSS the light bulb with the second meter. You have to take these readings at the same time with different meters and then calculate the power with these results.

Good luck with your experiments.

[juiced]

I never even thought about the open voltage part!! Thanks alot!

    I guess a cheapo-meter might be in order sometime in the future but not yet.