what would be a sufficient DC power source to power 12 average LED's?

[theman]

i mean like one of those big bulky things you plug into the AC outlet, Im looking for the current in Ampere mA.

 

[billrussell42]

Typical LED is 3 volts at 20 mA, although there is a lot of variation.

so you need tither 36 volts at 20 mA or 3 volts at 240 mA, but it gets more complicated as you need resistors to limit the current. I'd find a supply like 12 volts, and then put a few LEDs in series with the proper resistor. Repeat that series string until you use all 12. Exact number in series and resistor value depends on the specifications of the LEDs.

PS, don't buy LEDs without specs.

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