Nichia GS AG3/LR41 keychain twisty

[Hrvoje]

Few days ago I received 10 Nichia GS 5mm leds from LED1.de. I was curious what is so special about these leds, so ordered some to play with.
I had some AG3/LR41 button cells, and decided to build tiny twisty keychain light. At first I tried direct drive, but current at the cap was more then 30 mA. I'm not fan of overdriven led, so I redesigned caps and put resistors in it. First prototype has 18 Ohm resistor, and current draw is about 20 mA. Second prototype, which is rather simplified construction has 33 Ohm and current is about 10 mA.
Run time on the first model is about 2 h, the second one is not yet tested.
Dimensions of the first one are 41x10.5 mm, and the second one 40x10 mm.

Hrvoje

 

[Al Combs]

Very nice handiwork.

Is the beamshot that has more blue the 20 ma version? Or is that just a coincidence. There doesn't seem to be much difference in output between the two.

Thanks for sharing.

 

[savumaki]

VERY nice indeed; looks to be the perfect size for a keychain/pocket light.

I once received a similar light as a grat. with an order I received (cannot remember details) which I showed the wife and guess who's got it now???

Now I imagine you will get requests on end to turbo power/increase bat. cap./more throw/more flood and whatever else to abortion a good product.

Looks great. Thanks for the contribution.

 

[Hrvoje]

Al, you are right, left is 20 mA version. True, there is no much difference in output. But, I'm surprised with GS output at 20 mA, which is the same or even greater then other 5 mm led overdriven at 40-50 mA. I will try some resistors with the greater value. For such an efficient led like Nichia GS, even 5 mA would be sufficient. This type of flashlights are not intended to be super bright, they are for backup anyway.

Hrvoje