Signal Presence Detectors?

[Buck Buchanan]

Don Tillman wrote:
> Martin and Juergen both suggested using a current steering technique
> to drive the LEDs instead of simply switching the LEDs on.  This is a
> *great* idea.  Otherwise, if I had a couple dozen LEDs triggering off
> a common musical signal it would involve current glitches of 100mA or
> more, sure to mess up a high fidelity audio signal somewhere.
> 
>          (snip description of solution)

Hi all,

Ok, right off the bat I'll admit that I'm probably missing the bigger
point.  My comments are strictly in regards to large current draws
dirtying up the power supply.   I immediatly wondered if a just plopping
down another regulator (78xx, 78Lxx, etc) and filter cap to drive the
display section might be easier.  There's a couple of volts dropout to
contend with but that doesn't seem like a big problem for a display.  Or
is it that these regulators w/cap still won't provide enough isolation
for your needs?

Just a thought,

Buck