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Stef · 9th December 2006, 19:09

Just some info on LED's
Red, Green and Yellow needs 1.7V and 20mA (absolute max is 40mA)
Blue and White LED needs 3V / 20mA (max 40mA)
(voltage can change a bit due to make or current)

So 1 blue or white LED needs next resistor:
12V-3V = 9V ( U over resistor) then 9V/0.02A = 450ohm resistor
(470 ohm is standard value).

You can use 3 white LED's in series, leaving a drop of 3x3=9V

Then you need a resistor:
12-9 = 3V > 3V/0.02 = 150ohm ( 180 or 120ohm is a standard value)

Mind also that the car voltage can go up to about 14V.

9th December 2006, 19:09	#13 (permalink)
Stef Supporter Triangular Exhaust Join Date: 14th October 2006 Location: Belgium Posts: 367 Thanks: 0 Thanked 1 Time in 1 Post iTrader: (0)	Just some info on LED's Red, Green and Yellow needs 1.7V and 20mA (absolute max is 40mA) Blue and White LED needs 3V / 20mA (max 40mA) (voltage can change a bit due to make or current) So 1 blue or white LED needs next resistor: 12V-3V = 9V ( U over resistor) then 9V/0.02A = 450ohm resistor (470 ohm is standard value). You can use 3 white LED's in series, leaving a drop of 3x3=9V Then you need a resistor: 12-9 = 3V > 3V/0.02 = 150ohm ( 180 or 120ohm is a standard value) Mind also that the car voltage can go up to about 14V.