Need input. Running XML2 LEDs on a 12v Power Supply?

[Orion]

Right! Series! That's what I meant.

 

[LEDPunisher]

I know that there are LED bulbs with the traditional house lighting screws to replace incandescent lights, but they must have some sort of major resistence to counter the 120 volts.

Well, yes and no, IIRC. The 'resistance' is the electromotive force needed to overcome the voltage drop. When wired in series, this force adds up (which is why you need 12V to overcome your three LEDs in series instead of 4V that you would need to run in parallel, where your amps add up instead.) The thing about LEDs is that while their forward operating voltage is one number, their reverse break down voltage can be double or more that of the forward voltage, thanks to quality improvements in the manufacturing process of the p-n junctions. With this knowledge, you can run LEDs directly off of mains power, like I did here in this video.



However, this is not the case with regular household LED bulbs. Instead, you'll find inside the base a combination of a step-down transformer (or a variac) a capacitor or two, a resistor or two, and a couple of diodes. Maybe a fancy IC driver if it's not a cheap bulb. This brings the voltage down to what the LEDs are made to handle, and also helps to smooth out/eliminate the mains frequency flicker that you see happening in my video.