Re: LED control circuit

On 19 May 2006 05:32:03 -0700, "gstringe" <egnirts@xxxxxxxxxxx> wrote:

Aha, thanks Mac, I had the counter part figured but hadn't thought
long enough about it to come up with the rest. I might think as an
example that the outputs of lets say a 4017, one would turn on a
transistor fed by the steady bus and the next output would turn on a
transistor that was fed by the flash bus and the next one ground...Hmmm
not bad thanks for the jog in the brain. The next step is can I make
it simpler? Other than size I can't get much lower cost than a 4017,
two transistors and a pushbutton. Right now I have three switches &
three LEDs mounted on a single gang electric cover plate. Might get
crowded. Could also put the control circuitry at a central place with
the power supply. Why do I get myself into these things ;-)

Because it's fun!
One other thing you need to consider. If you're using long wires to
connect pushbuttons to your circuitry, using all these nice logic
gates means you may need to protect the inputs that connect to
pushbuttons from static and remote lightening strikes. A series
resistor and pair of diodes will work. Don't forget to debounce your
pushbutton.

vcc
|
-
^
|
pushbutton----R----+---gate input
|
-
^
|
gnd

---
qrk
.

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