Battery powered LED questions?

[Anjow]

On the one hand I think this may sound a bit weird, on the other this is the modding forum and anything goes around here...

I'm going to get hold of a mannequin as decoration for my room. I'm going to put it in my clothes, put a scary mask on it and put red LEDs in its pupils. Of course, this mannequin is going to be freestanding so I'll need to power the LEDs with batteries - the problem is I know squat about electronics.

I was looking at these (http://www.lsdiodes.com/shop/index.php?main_page=product_info&cPath=1&products_id=17) LEDs to use and I'd be using 2 of them. How should I arrange the power to them? What batteries would I use? Would I need resistors? Any idea how long batteries would last?

In addition to the questions above, does anyone have some suggestions for this mod?

[ilikepie]

I would wire them up im parallel and connect them to a 3v source (2 AA or something). The max voltage is 2.4v so you should use a resistor but i wouldnt bother but it should run fine at 3v but lower the life span. Im not sure about how long the batteries would last but if the batteries have 2000mah and the draw of the leds is 60ma that would be 33 hours. Im not sure about that though. I would use a old dc power adapter if the mannequin isnt gonna move much so i wouldnt have to deal with batteries.

[Phrenetical]

Just mod the stupid manequin,

M<ount a PSU inside it, and hook up heaps of LED's, and an lcd screen, infact why not turn your whole manequin into a small PC, and when windows errors the eyes can flash and play some maniacal laughing sound.

Honestly why are you even going to the trouble of led's, if your gonna mod your manequin do it right!.

^_^

[Anjow]

To be honest I HAD thought of the PSU thing - simply because I know how to get LEDs working with one, having done it before. However I don't think it would be too safe, and I'd have to have it plugged in.

[hafa]

Simply use 3 LEDs in series connected to a 9V battery and hide the 3rd LED. The 9V battery connectors are simple and available for <$1 at Radio Shack.

[Navig]

Linear-1's LED faq. (http://led.linear1.org/category/led-basics/)

So if you use your linked LEDs, you will need to deliver 2.1-2.4 V for 2 LEDs. So if you link your LEDs in parallel, you will need a 2.1-2.4V power source. If you link your LEDs in series, you will need a 4.2-4.8V source.

You're probably better off hunting around for an LED that can support 3V forward voltage. The reason being standard AAA batteries are 1.5V. Therefore 2 batteries in a series connector will give you 3V. So: 2xAAAs in series to power 2x3V LEDs in parallel. Or you can do the 9V trick above. Connectors and battery packs are available at Radioshack. In fact, if you're lucky and have a decent Radioshack nearby, I'm sure someone there would be happy to set you up with everything you need.


navig

[ponkan pinoy]

BetaBattery! Radioactive decay to provide electronic energy. Tritium has a half-life of 12.3 years, which means it'll take almost a quarter of a century for the cell's output to go down to one-fourth its original power!