Electrical schoolwork...

[Huw Powell]

I prefer this answer to Ti's current based calculation.

I would recommend testing your choice "out in the open" before 
rebuilding a fistful of switches, etc., to make sure you got it right.

SJ wrote:

>>From: "Louis-Alain RICHARD" <laraa at sympatico.ca>
>>
>>Resistance value of the LEDs: 150 000 ohms 
>>Ideal voltage at the LEDs: between 2.5V and 3V.
>>Electrical voltage at the switches: 13.6V, permanent, switched by the
> 
> 
> ***** For 3 volts
>  x/150k = 12v/3v
> x = (12v/3v)*150K
> x = 600K
> 
> 
> for 2.5 volts
> x/150k = 12v/2.5v
> x = (12v/2.5v)*150k
> x = 720K
> 
> You dont need an exact value. Anything close will do.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/