RE: LED rules of thumb

["Dr John Tankard" <john@xxxxxxx>]

> Doing it this way should be safe for the LED and avoid the 
> maths side of things. I don't know the formulas off the top 
> of my head so cannot help with that at the moment.
> 

The maths is like this, use ohms law

V=IR or R=V/I

So a 30ma current with 5v
Is R= 5/0.03 = 166R

Actualy you will find two items If max and If Typ, wich is usualy much
smaller

A typical on I use is 10mA 3v

R= 3/0.01 = 300R

John

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