How To Use LED's

Step 5: Resistors

It always helps to wire a resistor into your circuit. It will make the LED last longer by dropping the voltage. There are some sites that make it easy to find which resistor you need. My favorite is here.

Comments

[mr_bandit]

The resistor is to limit the CURRENT, not the voltage. The two things this article is lacking is a schematic and a simple picture of the circuit soldered up. The long lead is on the voltage plus(+) side and the short on the minus (-) side. The resistor is in series with the LED, on either side of the LED: (+) --- resistor --- long lead --- short lead --- (-) or (+) --- long lead --- short lead --- resistor --- (-) A resistor in the range of 1K to 10K is usual. Note some LEDs connected directly to a watch battery will work without a current-limiting resistor, but it is iffy and not good practice. (more in-focus pictures would be nice ...)

[NiftyJunk]

Yeah, its that little flower button on the camera. You know, for close ups. I was so happy when I found out what that little function does.

[imarzouka]

My favourit is http://ledcalculator.net :)