Re: Random thoughts on sinewave oscillators

"Cursitor Doom" <cd999666@notformail.com> wrote in message news:veu45s$3cmo3$5@dont-email.me...

On Fri, 18 Oct 2024 11:25:19 -0400, Edward Rawde wrote:
>

"piglet" <erichpwagner@hotmail.com> wrote in message
news:vetde5$38sbk$1@dont-email.me...

Edward Rawde <invalid@invalid.invalid> wrote:

>
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.
>
>

Could that just be second harmonic distortion? You could test the
amplifier by uncoupling the Wien network and injecting test inputs.
>
Elsewhere I think your amplitude control problems could be simply due
to too much gain.

>
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.

>
That's the main purpose behind having a thermistor or filament bulb in the
f/b path.

Sure, but why use thermistors or filaments if you don't have to?
Filaments don't last forever, particularly not if you drop your equipment, and filaments make me think of something like a 5U4.
I forget when I last saw a filament. House lamps don't even have them now.

I'm trying to make a low cost oscillator which produces the cleanest 1K Hz sinewave I can get, using only resistors, capacitors and
semiconductors.

There are plenty of examples online, but some of them don't seem to simulate.
Whether that's because they do work in reality but not in simulation is hard to say.