Re: Random thoughts on sinewave oscillators

On 17/10/2024 7:55 am, Edward Rawde wrote:

Is the reason why this doesn't produce a better looking sinewave because the amplifier slew rate is faster going down than it is
going up or some other reason?
 Ignore the wild decoupling, it took me long enough to get the concept to work at all.
 I'm aware that a single package containing two op amps could probably do a much better job.

https://www.analog.com/media/en/technical-documentation/application-notes/AN132f.pdf
has a pretty good example of a sine wave oscillator. I've speculated that a four quadrant analogue multiplier could offer a better gain control mechanism.
https://www.analog.com/media/en/technical-documentation/data-sheets/AD734.pdf
though it is hideously expensive. The simulation I worked up used two with the second one controlling a quadrature input to give you smooth control of the frequency of oscillation in addition to its amplitude.
I thought about building one, but there's no obvious application.
--
Bill Sloman, Sydney