i need some help guys

[spart666]

ive got to sort out my billet indicators ones blown taken it apart and need to rebuild them so off i go to maplins and buy some high bright orange leds tells him what im running and off i go (yea i know leds cheaper on ebay) so what i got after spending time solidering them together is two fucking red leds 2 blue leds that are half the power of the red ones needles to say im fucked off >:(
reason for bothering is the flush mounted billet indicators i cant get any more and anything else wont look right :-/

http://i15.photobucket.com/albums/a389/spart666/12.jpg

so ive bought a load of leds on ebay and need to know what resistor to use
heres the spec of the leds im using 5 rigging them up in line with a resistor on the positive feed 10 amp fuse protects the indicator circuit


Forward Voltage (V) < = 2.6
Reverse Current (uA)< = 30
Luminous Intensity Typ Iv (mcd)6000 - 7000
Absolute Maximum Ratings ( Ta = 25°C )
Max Power Dissipation PM = 80 mw
Max Continuous Forward Current IFM = 30 mA
Max Peak Forward Current IFP =75 mA
Reverse Voltage 5 ~ 6 V

cheers guys in advance

[fimpBIKES]

why not just buy the LEDs with the resistors built in to run off 12volt?

or you can buy these sorts of things and they're still pretty cheap
http://cgi.ebay.com.au/2-x-3-LED-Turn-Signals-R1-R6-GSXR-SV-TL-ZX6-ZX12-CBR-F4_W0QQitemZ270280784713QQihZ017QQcategoryZ35232QQ tcZphotoQQcmdZViewItem

[mods]

When you say "rigging them up in line", I assume you mean "in series". If so, when one LED fails you will lose the whole string. Better I think to set them up in parallel, so that loss of one LED will still leave you with 4.

I remember reading somewhere that 10k Ohm is about right for LED indicators, but I'd want to get some confirmation on that before I considered it gospel.

Maybe some folks out there will back me up........ or shoot me down.

Anyway, hope it helps.

[red]

OK, you have to use Ohms Law. This is the formula: V=I.R

Voltage(V) = Resistance(Ohms) x Current(A)

Do you know the voltage & current draw of your LEDs? Typically they are 20mA and 2V for orange ones I'm assuming your using?

Firstly, since you will be running in parallel, subtract the LED voltage from the 12V on your bike. Lets go with 2V and say your resistor needs to get rid of 10V.

V=10V
I=20mA (0.02A)
R=?

V=I.R so R=V/I
R=10/0.02
R=500ohms

Next thing to figure out is the wattage the resistor will need to be. This is one formula for it: P=I.I.R

P=0.02 x 0.02 x 500
P=0.2Watts

You need a 0.2Watt, 500ohm resistor for each LED.

But you could use a 2Watt 500ohm resistor to run front and back indicators (4 LEDs each wasn't it?).