# Forum: Analog Circuits How to adjust RC oscillator circuit frequency?

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Hello folks,
Recently I am working on RC oscillator circuit according to here
(source:
https://www.kynix.com/Blog/What-are-Oscillator-Types-Example-with-Diagrams.html),
it effects amplitude too (amplitude is changing while adjusting
frequency), how can i separate these two variables ? I mean, when I am
adjusting frequency, I want to amplitude remains same, and also for
amplitude too. By the way I am using this circuit: (Ignore the opamp
circuit, it is converting sinusoidal wave into square wave.)

Any idea of it? Thank you in advance.

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Thats quite easy.

Use a ceramic adjustment tool for the frequency and
another tool for the voltage.
Determine the correlation between frequency change and
voltage change vs. voltage control and frequency control.
the final values in one step.

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Lernend B. wrote:
> I can adjust frequency but it effects amplitude too (amplitude is changing
> while adjusting frequency), how can i separate these two variables ?

Or a little bit longer: you can, but you must add much more parts into
your schematic to keep the oscillator sinusodial AND to stabilize the
amplitude of the output signal.
So the first step is: generate a sine signal.
Second step is:  stabilize it to a stable amplitude.
And the last step is: amplify it to the desired output swing.

Thats why real world signal generators are more expensive compared to
some C, R and a transistor.

> Any idea of it?
Whats the actual problem?

: Edited by Moderator

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Lernend B. wrote:
> Hello folks,
> Recently I am working on RC oscillator circuit according to here
> (source:
>
https://www.kynix.com/Blog/What-are-Oscillator-Types-Example-with-Diagrams.html),
> ..........................
> Any idea of it? Thank you in advance.

* What is the required tuning range (frequency)?
* What is the required amplitude range?
* Is it allowed to vary two components in parallel?
* Are you required to use the shown circuitry (phase shift principle
with a BJT)?

You should know that there are many different and versatile oscillator
circuits (more than mentioned in the referenced paper), which - probably
- are more suitable for your needs....

: Edited by User