Hey-o... if anyone's still around this time of year, I've got a question for ya.
I want to attach 2 LED's in series to a 12v power supply from my computer (
EFY5366x). I just wanna make sure I have the the calculations for the resistor right (see diagram below).
Their total current draw is 60mA, and their total voltage drop is 3.6V. So
12v - 3.6v = 8.4v
And from V=IR, we get
R = 8.4v / (60/1000)A = 140 ohm.
Is that right, or do I not understand the problem at all?
Also, I seem to remember that you're supposed to put the resistor before the LEDs... is this right?
[Edit]Just realized the LED's I linked to aren't the 1.8v 30mA I put into the diagram... for sake of argument, let's say I was using 1.8v 30mA LED's...