Re: Final final 1kHz oscillator

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vi7cks$26f3$1@dont-email.me...

On 27/11/2024 7:48 pm, JM wrote:

On Tue, 26 Nov 2024 15:32:38 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
>

On 25/11/2024 1:02 pm, Bill Sloman wrote:

On 24/11/2024 5:10 pm, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 24/11/2024 5:11 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 23/11/2024 4:12 pm, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 23/11/2024 3:32 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 21/11/2024 1:00 am, Bill Sloman wrote:

On 20/11/2024 2:03 pm, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 20/11/2024 1:29 pm, Bill Sloman wrote:

On 20/11/2024 12:59 pm, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
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On 18/11/2024 2:58 pm, Edward Rawde wrote:

"JM" <sunaecoNoChoppedPork@gmail.com> wrote in message
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On Thu, 14 Nov 2024 11:14:28 -0500, "Edward Rawde"
<invalid@invalid.invalid> wrote:
>

"JM" <sunaecoNoChoppedPork@gmail.com> wrote in message
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On Fri, 8 Nov 2024 15:43:41 -0500, "Edward Rawde"
<invalid@invalid.invalid> wrote:

>

...

>
When evaluating architecture there's little to be gained by using a
complicated opamp model.  Use a simple 1 or 2 pole model to begin
with.
>
Try the attached file, I've used a simple model to speed up the
simulation, and made a slight circuit change.  This shows the
harmonics due to the control loop to be sub 130dBc.  Of course the
amplifier harmonic distortion is not simulated, but neither was it in
the simulation by Mr Rawde.

>
Thanks for that. I've got it into a form that my copy of LTSpice recognises as a .asc file, so I have looked at it.

I get 140dB down at 2kHz, 130dB down at 3kHz

>
I haven't run it yet because I'm running yet another variant of the circuit, which has got to 2.4 seconds, and I'll leave it
running overnight.
>
I'm currently curious about the effect of the phase of the 2kHz component in the control signal (coming from my full-wave
rectifier), and a fast simulating version of the circuit is just what I need to get that sorted out. I had thought that that it
would be trivial to get the phase right, but my first attempt didn't get close.
>
I could go mad and put a version of the circuit into KiCad and create a printed circuit layout and get some Chinese firm to make
and load the board.

I could too but I already know what 1kHz sounds like and I doubt that my ears can tell the difference between harmonics 120 and
130dB down.

>
It would be an extravagance, but nothing dramatic.
>
--
Bill Sloman, Sydney