Question About LEDs

[AMD Killa]

Hi, I am thinking of making some sort of light thing for my mums birthday present. I dont know much about LED's. I was thinking about buying them from maplins (im UK ;) ). These were the ones I was going to pick:

http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=2047&doy=15m8

Not sure what colour yet. Could someone tell me how to run 8 of these LED's off of an old 230Watt pc power supply I have lying around. I know how to short the power supply so it will work without the pc (gonna put a switch there too).

The specifications for the LED's are further down the page on the link above. Im guessing that I have 2 lots of 4 in series. Also, Im guessing that I would need a resistor, but I dont know the resistance I need.

This is a 2d export from sketchup:

http://img526.imageshack.us/img526/748/sketchuptt7.png

I was thinkging of putting the power supply in the bottom part, and also including a draw or a small cupboard there too. The top is going to be made from plexi that I am going to frost ;)

I just need to know about the LEDs (the resistor I need, and how to wire them up).

I should be modding a tower as soon as I have one come in!

[DonT-FeaR]

ok some one will correct me if a i am wrong but you you will need 2 sets of 4... i dont think you will need a resistor im not sure but i dont think because they are high voltage

some one correct me

[rerkin88]

Try this (http://led.linear1.org/led.wiz) site. Helps a lot with the resistors and the colour codes :)

[AMD Killa]

thanks for the link, I think I have it sorted now. Keep an eye out for the finished worklog between the beginning of september and the 18th. I have decided not to do a work in progress log and just do a finished log.

[rendermandan]

you could try this one too. http://ledcalc.com/

Just a suggestion, rather than using a huge 230 watt power supply, why not pickup a small 120v 12w power adapter from radio shack or some place? the kind that has the transformer that plugs into the wall.

[SgtM]

you could try this one too. http://ledcalc.com/

Just a suggestion, rather than using a huge 230 watt power supply, why not pickup a small 120v 12w power adapter from radio shack or some place? the kind that has the transformer that plugs into the wall.

That would work.. but I'm thinking 9v battery. That way the unit is completely self contained. Get a battery box from radioshack, then wire it up to the LED's. You could even throw a switch in there to turn them on and off.

[xmastree]

why not pickup a small 120v 12w power adapter from radio shack or some place?Or better still, make it compatible with your mum's mobile phone charger. Saves you buying an adapter, saves her having another one to get confused with, and she'll always know where her charger is!

Since you're designing it, you can make it work from whatever voltage you want.

[DonT-FeaR]

lol ive watched my dad mod with a hairdryer cable....

ruined the hair dryer

it was my paint dryer tho :(