How to make a led marker light?

[Spork]

I was wondering what would be the smallest and simplest way to make a led marker light. I want something that would run for about a year on the battery. Also a white marker would be handy if it could be made bright enough to read a map or something. or would it be better to stay with glowrings?

 

[zmoz]

If you want something that is going to run a year on batteries you are going to need a REALLY BIG battery. What are you marking?

 

[Spork]

just anything really, give them to the kids as night lights or whatever. how does the palight run for 2 years on a 9v? i was wanting to do something similar.

 

[pedalinbob]

well a single nichia on 3 d cells running at about...maybe 6 ma...enough to read with in the dark.
i think it might run a year.

anybody know if this is true?

Bob

 

[bj]

Another thing to try is to run the LED off of an oscillator circuit, to flash it really fast. Your eye tends to integrate it, but in reality it's only on half the time. Something on the order of a few milliseconds on, a few off, probably won't flicker too badly. I've done this with high power ones, where putting them both on would drag down the battery, so we just alternated them really fast and it came out ok.

brian

 

[Ty]

I made a blinking marker light with an LM3909 and an ultrabright red LED running off a D battery about four years ago. It blinks about once a second, and is still going. If you can deal with a blinking light (maybe add a switch to make it continuous for reading, etc), you can really extend battery life. Of course, the '3909 isn't in production anymore, but there are some simple transistor ckts which do the same thing.

Off topic, there are also those small trituim-filled markers you can find on ebay. Those things aren't very bright, but they essentially glow forever, losing 1/2 their brightness every 12 years or so....