cd4017 how to prevent reboot

Thread Starter

Petrichor

Joined Dec 19, 2024
36
That is an odd circuit.
What exactly, is it supposed to do?
Actually, I don't know much about electronics. I built a circuit for my purpose with my own knowledge and it works fine except for the problem I mentioned. so it might be a little weird. Basically, when I press the next button 9 times, it needs to send a signal to 555 sequentially and the LED should flash with each signal. The reason why I did not connect the LED directly to the CD4017 is because I do not want the LED to remain on all the time. Additionally, when the final output is reached on the CD4017, the circuit should not return to the beginning. However, when the reset button is pressed, it should return to q0. The only problem now is that I cannot create a time difference between CD4017 outputs.
 

crutschow

Joined Mar 14, 2008
38,515
It's too awkward to comment on your circuit without component labels (R1, C2, etc.), please add those.

The PB switch symbol is ambiguous as to what it connects, please use something like this:

1734803635334.png.

I assume you mean microFarad (uF) not milliFarad (mF) for the capacitor values.
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
It's too awkward to comment on your circuit without component labels (R1, C2, etc.), please add those.

The PB switch symbol is ambiguous as to what it connects, please use something like this:

View attachment 338590.

I assume you mean microFarad (uF) not milliFarad (mF) for the capacitor values.
Yes, as I said, I'm a bit of a novice. Actually, you don't need to focus much on the buttons. Even ignore the whole scheme. The problem is that there is no time difference for switching between cd4017 outputs. And (I will give an LED example to simplify it) an LED connected to all outputs remains on without going off at every pass. The LED must turn off during transitions, even for 10 milliseconds. Or vice versa, it needs to burn even for 10 milliseconds during transitions.
 

crutschow

Joined Mar 14, 2008
38,515
you don't need to focus much on the buttons. Even ignore the whole scheme.
That makes no sense.
To understand the problem I need to know exactly how the buttons and circuit works.
And if you want my suggestions on solving the problem, please make the schematic changes suggested.
How do you think it's possible to help knowing only the problem without understanding the circuit?

Or do you just want me to generate a whole different circuit to do what you want?
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
That makes no sense.
To understand the problem I need to know exactly how the buttons and circuit works.
And if you want my suggestions on solving the problem, please make the schematic changes suggested.
How do you think it's possible to help knowing only the problem without understanding the circuit?

Or do you just want me to generate a whole different circuit to do what you want?
No, I'm not asking you to design a new circuit. Here you go, I think this circuit is understandable, let me ask the same question again: How can I prevent the LED from staying on all the time?

1212.png
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
Since the problem is likely with the 555 circuit, why did you eliminate that from your schematic?
If you can't show a complete schematic with the changes I requested, then I can't help you.
because I know the problem is not in 555. Actually, I don't want you to solve a problem. I just want the LED in the image I posted to blink, that's all. I don't understand why you can't help? I just want an opinion on what I'm saying.
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
And how did you determine that?
My opinion is that there is an error in your circuit design, and likely with the 555 circuit since that's what provides the LED blink.
Without understanding the complete circuit, there's nothing else I can add.
I can't be clearer than that.
Then you have no chance of helping me anyway. Because as I said, the problem is not 555. When I connect the 555's trigger to a button, not the CD4017, and press the button quickly and repeatedly, the LED turns on without any problems. So the only problem is that there is no time difference between cd4017 transitions. I don't think you need 555 images to solve this problem. Additionally: One of the reasons why the problem does not occur in the 555 is that I can get 2 signals when I connect the trigger to q0 and q2. The problem starts when I connect it to q0 and q1.
 

BobTPH

Joined Jun 5, 2013
11,518
@crutschow:

He is trying to trigger the ‘555 on each transition of the 4017 by diode oring together all the outputs. This will never work because one of them is always high, so it never goes low. It is trivial to fix, but his attitude has caused me to withhold further help.
 
Last edited:

Thread Starter

Petrichor

Joined Dec 19, 2024
36
@crutschow:

He is trying to trigger the ‘555 on each transition of the 4017 by diode oring together all the outputs. This will never work because one if them is always high, so it never goes low. It is trivial to fix, but his attitude has caused me to withhold further help.
You understand the problem, you know there is no solution to the problem (in the way I said) and you say it now? There have been 50 messages in the thread and there is nothing but "what do you want to do" message. I have said many times what I want to do and now you say there is no solution. What kind of attitude did you expect? There are 2 days left on this project and I have no time to waste. I hope you understand.
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
Okay, I'm done.
I'm quite sure I could help you, but since you think you know where the problem is, good luck in solving it.
and I say the same thing again: There is no problem. I just need the time difference between passes. Apparently this is quite difficult to understand. If that's not possible, you can say it's not possible. If possible, you have an idea.
 

crutschow

Joined Mar 14, 2008
38,515
There is no problem. I just need the time difference between passes.
Okay, against my better judgment I will continue this little farce.

Yes, there is a problem, which you just stated, and it's not necessarily as easy to solve as you seem to think.

The difficulty is caused by not thinking through how best to perform this task.
You are trying to trigger the 555 from the CD4017, when it would be simpler to trigger the 555 through the PB switch from the Q9 output, and have the 555 output be the clock for the CD4017.
That would also eliminate all the diodes and the transistor.
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
Okay, against my better judgment I will continue this little farce.

Yes, there is a problem, which you just stated, and it's not necessarily as easy to solve as you seem to think.

The difficulty is caused by not thinking through how best to perform this task.
You are trying to trigger the 555 from the CD4017, when it would be simpler to trigger the 555 through the PB switch from the Q9 output, and have the 555 output be the clock for the CD4017.
That would also eliminate all the diodes and the transistor.
As I said, you could have explained this sooner. I'm short on time and I have a project to finish. But Thanks for the reply. I'll try this tomorrow. Since I'm a novice at building a circuit, it will be a bit difficult, I hope it works.
But there is something I don't understand here. Which output will the LED be connected to? If it is to be connected to CD4017, how will the diode problem be solved and how will the high-to-high transition problem be solved?
 
Last edited:

crutschow

Joined Mar 14, 2008
38,515
As I said, you could have explained this sooner. I'm short on time and I have a project to finish.
Your lack of planning to meet a deadline is not my concern.
I would have replied sooner if you weren't so uncooperative in doing what I asked, so I could better understand how your circuit was supposed to work.
Which output will the LED be connected to?
The 555, which will pulse each time the PB is triggered , until the CD4017 reaches count 9, at which point pressing the PB will have no effect (which I believe is what you want, but that was never completely clear).
Note that the PB trigger connection to the 555 will likely need to be capacitively coupled.
 

Thread Starter

Petrichor

Joined Dec 19, 2024
36
Your lack of planning to meet a deadline is not my concern.
I would have replied sooner if you weren't so uncooperative in doing what I asked, so I could better understand how your circuit was supposed to work.
The 555, which will pulse each time the PB is triggered , until the CD4017 reaches count 9, at which point pressing the PB will have no effect (which I believe is what you want, but that was never completely clear).
Note that the PB trigger connection to the 555 will likely need to be capacitively coupled.
So, if I continue pressing after the 9th pulse, will the cycle return to the beginning or will it stop burning completely (which it should) and if it does, how will I return it to the beginning?
 

crutschow

Joined Mar 14, 2008
38,515
So, if I continue pressing after the 9th pulse, will the cycle return to the beginning or will it stop burning completely (which it should) and if it does, how will I return it to the beginning?
It stops, since when Q9 goes high, the PB signal to the 555 will stay high and not trigger the 555.
To return, you just reset the CD4017, as in your circuit.

Below are the sim graphs of a circuit I generated using that scheme;
Note that the PB presses (yellow trace) gives 9 pulses from the 555 (green trace) until Q9 goes high (blue trace), and then continues only after the CD4017 reset (red trace).

A note if you are interested in doing circuit design (or any design) :
Always think of as many ways as you can to perform a given function, and then select the best one.
The first way you think of, is seldom the best way.


1734889043814.png
 
Last edited:

Thread Starter

Petrichor

Joined Dec 19, 2024
36
It stops, since when Q9 goes high, the PB signal to the 555 will stay high and not trigger the 555.
To return, you just reset the CD4017, as in your circuit.

Below are the sim graphs of a circuit I generated using that scheme;
Note that the PB presses (yellow trace) gives 9 pulses from the 555 (green trace) until Q9 goes high (blue trace), and then continues only after the CD4017 reset (red trace).

A note if you are interested in doing circuit design (or any design) :
Always think of as many ways as you can to perform a given function, and then select the best one.
The first way you think of, is seldom the best way.


View attachment 338656
Thank you for everything, and for your tolerance. I can be a little aggressive when I'm stressed. Problem solved.
And I will take you advice into consideration.
 
Top