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?
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?
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.
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.
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:
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:
Hi
If that RED dot on your circuit is a n/o push switch.?? then as you push the switch the cap will charge, BUT as the switch opens the only discharge path for the cap is via the reversed biassed diode.
So it will [ with an ideal diode] take a very long time to self discharge.
Your test circuit is not a true analog of what happens in an actual circuit.
Try place a resistor in parallel with the cap, so it has a discharge path when the battery voltage is switched off.
Hi,
I would like to help but I cannot determine what you are trying to do.??
You did ask about ic counter reset pulses, derived from a cap and resistor across the +V and 0V rails,
which I answered by showing the charge and discharge pulses.
Now you are comparing this with a loop circuit with capacitor, battery and LED in circuit.???
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.
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.