I was reading some articles online where it talked about this kind of RC oscillator.
I just want to clarify some caveats about this circuit:
From: https://learnabout-electronics.org/Oscillators/osc31.php it says: "even though using four filters does give slightly better frequency stability" while this article says: "By cascading three or even four RC stages together, the stability of the oscillator can be greatly improved."
I see a contradiction here. Which article is right about having better stability with 4 stages rather than 3? Does having 4 stages allow for greatly improved stability or just slightly better?
The second thing that I wanted to clarify/know about is the loading effect of the RC stages and its performance and stability/reliability of the circuit. It says here:
But because this formula is based on calculations for individual filters, it does not fully take into account the effect of connecting the filters in cascade, which causes of one filter to be 'loaded' by the input impedance of the next, as shown in Fig.3.1.3, where the input impedance of filter 2, made up of the reactance (XC) of C2 and the resistance of R2 effectively changes the value of the output resistor of filter 1 (R1) as they are effectively connected in parallel with it.
Could someone go into more detail about this and talk about how it affects the performance and stability/reliability of the circuit?