led question

[CertifyThis]

When you are doing your calculations for how large a resistor to use and it asks you the voltage drop across the led, do u addd up the voltage drop across all leds and add it up and put into calculation or just 1, they all run between 2-3v. and im puting 4 in succession with one another, so for calculating, put the total voltage drop across leds or across them all?

[domll]

Just found the answer to this one earlier (not electronically minded so feel like the cat that got the cream :D ), click link and hover over Voltage drop across LED for answer.

http://ledcalc.com/

Also take alook at this link for more. http://www.rcgroups.com/forums/showthread.php?t=985946

domll.