LED What size resistor tool

[Mooseman]

A very useful tool for working out what resistor you need to add when your making mods.

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

click on the ? For hints on what values to use.

moose.

 

[Snux]

I have this app installed on my Android phone...

https://play.google.com/store/apps/details?id=it.android.demi.elettronica&hl=en

It's free and has all kinds of useful things - resistor value (colour code) calculator, LED resistor calculator and loads more things.

 

[Pinballdoctor]

Didn't you guys learn this at school ?

R = U * I ....etc

but must say........very handy