Wiring some LEDs

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WipeoutFTW

Limp Gawd
Joined
Jul 17, 2006
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Hey all, im new to wiring and whatnot and this isn't for a case mod, but im sure this is the best place to get some feedback. For reference, im using this for a Big Daddy costume from Bioshock. More info about that in my signature.

Im wiring a total of 40 red and 40 yellow 5mm LEDs to a battery and a rotary switch with 3 positions (A, B, and Off) between the two. I created a crudely drawn schematic. I just wanted to see if there is anything I'm missing and what kind of battery would be best.

ledschematicfj9.png


Also, if anyone knows a place to order bulk LEDs for cheap, let me know. So far I was thinking about www.allelectronics.com

Thanks in advance.
 
With 40 2V LEDs in series for each colour, you want an 80V battery. They tend to be hard to find. If you put them in parallel, OTOH, you will need a 2V battery that delivers 2 x 40 x 0.050 = 4A. That's a little more reasonable - 6AA rechargeable NiMH set up for 2.4V @ 6AH will light you for over an hour (that's three sets of two 2000mA batteries - three pairs in parallel with each pair in series).

If you use a different LED type, figure out the amperage requirement for them and figure out what you'll need. You can fiddle with different arrangements of parallel and series LEDs to adjust the total voltage and amperage you need.
 
You need current limiting resistors... I would run 4 per loop with a resistor in series with 10 loops. 4A is alot to ask out of batteries.
 
Here's my suggestion:
--Get a 12V sealed lead acid battery--the size depends on how long you want to run the LEDs. If you follow the next suggestion, you'll be pulling about 160-240mA, which would run for a good long time even on a small SLA battery.
--Use this LED calculator to find out exactly how to wire everything. (supply voltage = 12, LED forward voltage = 2, current = 20 or 30, and number of LEDs=40). You'll do one for the red LEDs and one for the yellow LEDs.
--eBay is a great place to get large numbers of LEDs for cheap.

You don't necessarily *have* to use a rotary switch--you could also use an on-off-on DPDT toggle switch (which also has three positions).
 
Michael Daly said:
8 AA NiMH @ 2000ma will provide 9.6V nominally and with a 200mA drain will be drawn down at 1/10C, which is not bad at all.
Click to expand...

So will 6 Alkaline AA batteries... but you'll only get a capacity of around 1500ma (as an approximation, as we all know alkies can't really be rated).

Either way, you'll get 10 (NiMH) or around 7 (Alkaline) hours of uptime. Keep the battery pack cool too.
 
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