Re: Final final 1kHz oscillator

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vhadl5$2v27$1@dont-email.me...

On 15/11/2024 7:56 pm, Bill Sloman wrote:

On 15/11/2024 3:14 am, Edward Rawde wrote:

"JM" <sunaecoNoChoppedPork@gmail.com> wrote in message news:t5fajjdteskfftvkf84iqsp2vc4b9ta5kj@4ax.com...

On Fri, 8 Nov 2024 15:43:41 -0500, "Edward Rawde"
<invalid@invalid.invalid> wrote:

>
I finally got around to digging out my AD734 based Wein bridge simulation, and created a FET based version.
>
It's got a nasty 163kHz generator embedded in it somewhere, and I've put in an RL filter to keep that under control.

>
It looks as if the 163kHz was coming from the LTC6655-1.25V precision reference.
>
Putting in 4.7uF at C10 - rather than the 1.0uF I started off with - seems to make the simulation run a lot faster - about 20
times faster - and cleaned out the visible hash coming from the voltage reference.
>
The data sheet says use something between 2.7uF and 100uF and recommends film parts - ESR less than 0.1R.  They don't like ceramic
parts.
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Pulling out the LCR filter (L5,L6, C19, C20, R22 and R23) may have speeded up the simulation too.
>
The 2kHz and 3kHz harmonics aren't as good as they were - only about 65db below the fundamental - so Ill have to do some more
digging.

I changed C10 to 4.7uF and ran the simulation to 10 seconds.
L5 etc are still present.
FFT from 2s to 10s says 60dB down at 3kHz

>
--
Bill Sloman, Sydney