LED's And the Resistor size needed.?

Question

Hello, Ive looked but haven't got a straight answer... I'm looking to fine out what size resistors i would need for different LED colors and voltages...

So if someone knows could you please help me...The list is as fallowed...

Blue regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

Red regular and Diffused. 3mm & 5mm 3.3V 5V &12V

Pink regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

UV(purple) regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

Orange regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

Yellow regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

Green regular and Diffused. 3mm & 5mm 3.3V,5V &12V

White. regular and Diffused. 3mm & 5mm 3.3V, 5V &12V

or is there a site that has a list of resistor sizes for the voltage and LED size and color? Ive looked and haven't found anything...

Thanks for any help.

Answer 1

The link from the other answer is great.  But it's easy to do yourself.  Here are the steps.

voltage supply minus the LED voltage drop divided by the current draw.  

I'll assume a 20 mA current but use the current value for your particular LED.

In your first LED, 5 volts-3.3volts=1.7volts

1.7 volts /0.02mA=85 ohms.  Use the next higher standard value if this value isn't available.  

You can also series the LED's. Let's do 3 of them and use 12 volts.  By running LED's in series you reduce the number of resistors needed.  The power supply voltage always has to be more than the voltage drop of the LED or LEDs.  

12 volts-(3.3volts X 3 LED's for 9.9 volts)=2.7 volts.

3volts / 0.02 mA=135 ohms or the next higher standard value.  

  

  

Answer 2

not sure if you tried this site

http://www.llamma.com/xbox360/mods/How%2...