Self-Stabilizing Wien Bridge

126

01:15:30

This uses a VCA (Voltage Controlled Amplifier) to slowly adjust the gain depending on the amplitude of the oscillations to keep it under control while attempting to not distort it too much. As can be seen by slowing down the time scale, it is still slightly distorted. I feel rather unsatisfied with this circuit and am open to suggestions for improvements and constructive criticism.

published 8 years ago

hurz

8 years ago

All "wien bridge oscillators" are self stabilizing even the worst one in harmonics. What you mean is, you spend some extra effort for a sensitive amplitude regulating mechanisim to get a lower/less distortion one.

jason9

8 years ago

Yes. In my opinion, that isn’t really called self-stabilizing but more like reaching it’s limits which includes whatever distortion that may involve. Self-stabilizing implies that it stabilizes in a desirable way, not an undesirable way.

hurz

8 years ago

How desirable it is, just depends on the gain above 3. If you use rail clipping as regulating point and the gain you "press" against this amplitude is very low, then its not as desirable as you may think. Anyway, to compare fair, we would need numbers and not just words like "desirable".

hurz

8 years ago

Here a "undesirable" with THD 0.16% while yours I measured with 3.3% THD, hmmmmm http://everycircuit.com/circuit/5150151500103680

hurz

8 years ago

@jason9, if you stop communicate, what does that mean?

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