[sdiy] logic question

[Ethan Duni]

On Mon, 16 Apr 2001, Paul Maddox wrote:
> > i was wondering how one goes about implementing a "if greater than X but
> > less than Y" circuit.  i see a lot of circuits that will do X if greater
> > than a certain voltage, but say i have three LEDs that i'm feeding
> voltage,
> > and these LEDs go on at 1v, 2v, and 3v respectively.  if i get to 2v, i
> > don't want LED1 to still be on, and if i get to 3v, i don't want LEDs 1
> and
> > 2 to still be on.  how do i go about shutting off the first LEDs whent he
> > voltage goes higher?

-You might try a window comparator.  This is like a comparator but
implements "if x between y and z".  try:

appnote.stts.edu/Harris/an9802.pdf

Ethan