LEDs..how to go from 12v to 6v, I got 2 6volt leds and I need to tap them onto 12v power Options

[Black0nBlack94]

Any body have any idea how or what I should use to make a 6volt LED light on a 12volt power supply? I know that if I tap it on directly to the 12volt it will burn but I cant figure out how to make it light without burning. I want to install 2 blue LEDs, one on each door behind the lock and I plan to take power from the courtesy light. But After the current leaves the courtesy light and before it reaches the LED...I need to lower the current. I think I need a resisitor but I dont know specificly which one. If anyone has done this before let me know what I need to do. Thanks 6gcers

[jlive]

How to get 6V from 12V (V=IR, Voltage = Current * Resistance)

12V --- R1 --- R1 --- Ground

Let R1 equal a resistive value. Say 1 Ohm. The wire between R1 and R1 is then at 6V (12V/2 Ohms = 6 Amps... 6 Amps*1 Ohm = 6V). The Amperage going through the circuit though is high, 6 amps.

So lets make R1 a bigger resistive value. Say 1000 Ohm. 12V/2000 Ohm = .006 Amps... .006 Amps*1000 Ohms = 6V. The amperage then going through the circuit is 6 milliAmps.

Either way you get 6V between R1 and R1.

So adjust the resistors until you get the current value you need. Just make sure you keep the two resistors the same value, and that they can handle the amount of current being pushed through. Also make sure you also use a wire that can take whatever current your pushing.

Place the LEDs in between the two R1 Values like so:

12V --- R1 ------------- R1 --- Gound
.................|.........|
...............LED.....LED
.................|.........|
...........Ground..Ground

Ignore the periods, everything got shifted left when I posted it.

Depending on the LED, the current flow may change a little, just play with it until you get what you need.

Hope this helps.

This post has been edited by jlive: Sep 28, 2010 - 3:57 PM