Thread: LEDs
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Unread 29-06-2012, 10:53
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Re: LEDs

Quote:
Originally Posted by DonRotolo View Post
Any LED can be made to run from 12 volts by adding a resistor in series with it. You just need to know the necessary current (use 10 or 20 mA if unknown) and the color (= operating voltage).

So for a red LED (~2 volts) at 20 mA:
V = I * R or R = V/I
You need to drop 12 to 2 volts, or 10 volts
10 / 0.020 = 500 Ohms. Use 480 or 510 Ohms.

P=I*V, 0.02*10=0.2 Watts, 1/4 watt or larger is necessary.
Thank you Don! I was trying to figure this out the other day and, not being an engineer, didn't know how to apply the principal.

Simple examples = 1K words.
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