On 5/21/2010 5:25 AM, Invisible wrote:

>
> Of course, when you buy a kit, somebody else has already figured out
> what kind of LEDs to put in there, and what resister you need to connect
> it to. I recall routinely using ICs to drive LEDs - but that was TTL,
> and now I'm looking at CMOS, which has different characteristics.

Not that hard to figure out what kind of resistor you'd need to safely 
drive an LED for a given voltage.

You subtract the Vf of the LED from the supplied voltage, then use ohms 
law to calculate the resistance you'll need to drive the LED in its 
current range.

BTW, why CMOS? TTL is more robust for experimentation. CMOS you have to 
worry about damage from ESD, etc...

>
> Anyway, we'll see what happens I guess.


-- 
~Mike

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