Re: Random thoughts on sinewave oscillators

On 10/19/24 12:46 PM, KevinJ93 wrote:

On 10/19/24 12:13 PM, piglet wrote:

On 18/10/2024 4:46 pm, john larkin wrote:

On Fri, 18 Oct 2024 11:25:19 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
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"piglet" <erichpwagner@hotmail.com> wrote in message news:vetde5$38sbk$1@dont-email.me...

Edward Rawde <invalid@invalid.invalid> wrote:

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The circuit below produces a reasonable looking sinewave but the rise
time still seems to be slower than the fall time. It may be that the
amplifier in use is not ideal for this.
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Could that just be second harmonic distortion? You could test the amplifier
by uncoupling the Wien network and injecting test inputs.
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Elsewhere I think your amplitude control problems could be simply due to
too much gain.

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Perhaps, but I've not so far been able to get the circuit I posted in response to Bill to produce a sine wave no matter what I do
with the control loop gain.
It either grows to clipping or dies.
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-- piglet

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I do a lot of instant-start LC oscillators as the timebase of
triggered delay generators. I let them clip just a bit to stabilize
amplitude.
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Here is an amusing oscillator that has a voltage follower as the active stage - it has no voltage gain so some people say it cannot work - they are wrong of course.
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<...>

piglet
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 If you move the ground to the emitter of Q3 and slide R8 through the power supply to the collector of Q3 you can see that it is a conventional phase shift oscillator with feedback from the output of an inverting amplifier via a 3-stage RC network.
 kw
 

Somehow it was truncated?
This is what it was supposed to be:
If you move the ground to the emitter of Q3 and slide R8 through the power supply to the collector of Q3 you can see that it is a conventional phase shift oscillator with feedback through a three section RC network.
kw