can i use the Control pin of 555 timer to change duty cycle without changing the set?

[Amalinda]

can i use the Control pin of 555 timer to change duty cycle without changing the set frequency?

to be more precise,
i want to set a frequency in the circuit using a potentiometre. and when i change the potentiometre_2 the duty cycle must change without causing a change in frequency. I doubt if this is doable using 555.
if not,

Is there a way using op amps?

thank you.

 

[Tahmid]

You can do it simply with the common astable 555 circuit along with 2 added diodes. I've shown in your other thread: https://www.edaboard.com/threads/272601/#post1168830

 

[BradtheRad]

To demonstrate the result of what is described in the thread title...

Here is a screenshot showing the effect of a range of volt levels at the control pin of a 555.



It looks as though there is a range where the duty cycle changes yet the frequency is the same.

As a higher voltage is applied it is obvious the frequency gradually gets slower.