Re: help with 555 schmitt trigger resetting


zander wrote:

Whoops, I meant change R2 to 100k and leave R1 at 220k.
--
john

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

.

Relevant Pages

  • Re: 1% 8 bit R2R DAC @ 44KHz = Joke?
    ... 16bit shift register which has a storage latch, ... I.e. if I looked at the FFT of the original and the FFT of ... For audio eight bits ain't much ... Imagine that the MSB resistor is 1% off. ...
    (sci.electronics.design)
  • Re: How to count pulses per second ?
    ... There you go again John, ... You're a PIC programmer so that puts you at the forefront of ... why should he have to post a design to ... resistor, and an LED, no? ...
    (sci.electronics.basics)
  • Re: 431 shunt regulator help
    ... to use a TI431 to sense anything above 9 or 10 volts, ... eg; current resistor on Vin. ... If you were to tell us which A/D converter you were ... John Larkin is not only thin-skinned in his own right, ...
    (sci.electronics.design)
  • TOUGH dog solved: D52W135DYX1 pic blanking with audio playing (ATC221)
    ... Unit came in with intermittently blanking out picture audio still on. ... Almost looks like scan loss trip and no error codes tripped as well. ... video cuts out with audio still playing. ... I had ITC222 with x-ray resistor divider values going high and cause ...
    (sci.electronics.repair)
  • Re: Why extreme S-parameter values
    ... >> resistor in parallel with a small capacitor. ... John. ... I'm impressed by both the VNA accuracy and by the high collector ...
    (sci.electronics.design)
Quantcast