Re: [CAD_CAM_EDM_DRO] TTL questions

Marcus & Eva wrote:

> >Don't confuse a "pull-UP" resistor with a "series resistor".
>
> Hi All:
> What on earth is a "pull-up" resistor???
> Sounds like ( in the immortal words of my lovely wife) those situations in
> the morning where she's trying desperately to pull up her underwear and I've
> got my hands in the way!!

Whew! Sounds like we will get a censor if you keep saying things like that!

TTL and LS logic chips have asymmetrical output current capabilites.
They can sink (pull to ground) much more current than they can source
(pull to +5 V). So, in many cases where you need a greater current pulling
up to +5V, or a faster rise time, you connect a resistor to +5V, to supply
that additional current.

Jon