# Fairly new to LEDs...



## Beepem (Jul 17, 2006)

well ive used LED in soldering kits before, but thats completely different from me making my own curcuit. So I want 2 red LEDs.

according to 
http://led.linear1.org/1led.wiz

If I used a 4.5v source, I would need a 27ohm, 1/8w resistor. If I got a 6v source (so 4 batteries, right?) i would need a 100 ohm, 1/8w resistor. Would that be correct?


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## Otaku (Dec 3, 2004)

Depends on the forward voltage of the LEDs. If they're ≥ 3 volts you don't need a resistor at all. If I'm wiring a single LED, 3-4 volts, I use a 100 or 150 ohm resistor with a 6VDC source. If you do need to use a resistor, you can place it anywhere in series with the LEDs.


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## Otaku (Dec 3, 2004)

The only time I have not used a resistor for series LEDs was in the Spookyfire LED flicker circuits. I just wired directly to the 6VDC battery pack. If you want to use one or two non-blinking LEDs in the circuit, you do need a resistor. Green LEDs shouldn't glow orange and burn your fingers!


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