Re: help with 555 schmitt trigger resetting


Thanks john, I'll try that.
The TIP42's also drive a LED with 1k resistor, could the 10v on this
resistor when the lights are on be used to somehow reset the trigger?

No, because unless you can delay that somehow, if the circuit can reset
itself it will do so instantly. I'm not sure what output effect you are
looking for- just a light on when there's an audio input? If so, you
could detect the audio with an envelope detector (just a couple of
caps, a diode, a resistor) and a comparator to compare the detected
audio with some level. Then that could control the light. If the
circuit is supposed to make the light flutter or something, you could
use the envelope detector to gate the output of your existing circuit
so it would turn off when there was no input.
--
john

The output effect is, the lights flash in time with the loadness of
your voice.
lowering R2 to 100k didn't work well, the lights did always go out but
the effect was lost.
I'd like to try a envelope detector to trigger the 555 so it turns off
when there's no input.
Being a novice I searched online for info on envelope detectors and
found this link,
http://www.st-andrews.ac.uk/~jcgl/Scots_Guide/RadCom/part9/page2.html
but finding the values for C or R,looks complicated.
Would using an IN4148 diode, 100n cap and a 10k resistor be ok to try?
Does the diode connect to the existing C1?
--
Zander

.

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