I can't remember where I read it but I remember seeing that to make sure a ripple counter starts at 0 you put a really small cap the reset pin to V+. And then a high ohm resistor to ground.
When you take power away from the circuit how does the cap drain?
Viewed the link, OK
The important point to note, is that when testing this type of R/C circuit is that its actually a simple differentiater and so the applied test pulse voltage must have a 'fast' rise/fall time, if you want to see the RESET waveform.
axro;799189]Well I'm more worried about the discharge aspect. I'm not really going to use this for a ripple counter, it was just the example I remembered. I was going to use a capacitor as the momentery switch needed for a monostable 555 timer.
Here is my circuit, it's not the circuit i want, it's just a way of testing the discharge:
The red dot is an LED
If I put a resistor in parallel with the cap, when the cap fills won't the resistor continue to power the circuit? In this case the LED?
Ok sorry. Here is what I'm trying to do.
When a switch is turned on I want it to trigger a monostable 555 timer. Thats really all there is to it. I only want it to run once.
I was thinking of using a cap to provide the "pulse". But I must have been mistaken because to trigger a monostable you need to make the trigger go low.
I only want the monostable triggered once when the initial switch is turned.
So what would be the best way of doing this?