LED battery life and brightness problems

[sjaguar13]

I was looking at LED projects on another site and I seen really, really bright LEDs. I heard from somewhere that you could use magnifying lenses to make them appear bigger and brighter. Where would I get the lenses at, or how could I make my LEDs brighter? Also, is there a better way than putting 10 LEDs in parallel, so the battery lasts longer?

 

[Klaus]

You can boost the LED light with a fresnel lens to some extend. its a tiny version of the kind of lenses they have in light houses.
LED brightness, they are brighter if you run more current through them but you quickly reach a point when they burn out, better stick to the maximum current on the spec sheet for your particular LED.
Battery consumption, for a given brigthness you pass a given current through the LED. 10 LED's consume 10 times the current, there's no magic unless you start pulsing the LED's rapidly. That way you deceive the eye to think they are on all the time. You need to pulse around 50 Hz or faster or you will see flickering. You could reduce power consumption by half with that, at the expense of more complexity.
Have fun,
Klaus

 

[sjaguar13]

How much do fresnel lenses cost? I need 10 little ones. Where can I get them from, and can they be cut or do I have to find them in the right size?

 

[kinjalgp]

You can also use Ultra Bright or Super Bright LEDs. They have very high intensity as compared to normal LEDs. You can also try Luxeon Star LEDs from www.luxeonstar.com

 

[tansis]

You might also want to look at the Maxim semicondutor site they make ic's specifically for driving high brightness leds and you might pick up an idea or two from the applications note.
See previous discussion for "Battery-less LED flashlight"