<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redduck &raquo;</TD></TR><TR><TD CLASS="quote"> I went to a Radio Shack looking for some 12VDC white LEDs... That place just isn't what it used to be. They couldn't help me with the diodes, but I am thinking if I needed any cell phone accessories, I was in the right place!</TD></TR></TABLE>

The nature of LEDs will prevent you from ever finding a White 12V LED. The only way to get an LED to function at 12V is to add resistors. The COLOR of the LED determines the necessary voltage. a red led will burn at about 1.7 volts. a white or blue LED will need 3 to 4 volts. This is partly responsible for and also a product of why you see "4 little LEDs in one" You want a yellow LED (say for a turn signal), yellow LEDs use about 2.1-2.3 volts, put four in a series and you have a 8.4 to 9.2 requirement. Use resistors to drop off the 12volts to 9.2 (dropping 2.8 volts). Most stor bought LEDs run on 20 milliamps. Apply the following formula to determine R (R= the resistance in Ohms):

R = (12 - 9.2) / 0.020(amps, not milliamps here)

SO,

To run ONE super bright white LED at 3.4 volts ( i looked it up this time) from a 12V power supply (your motorcycle) you would need to truncate about 20% of the available voltage to accomodate fluctuations without making the LED 'flake out'.

so, 10V power supply.

10 volts - 3.4 volts = 7.6 volts.

7.6volts/ .020 = 380.

You'll need a resistor of 380 ohms, or a few that add up to 380, wired in a series.