Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: JM <sunaecoNoChoppedPork@gmail.com>
Newsgroups: sci.electronics.design
Subject: Re: Final final 1kHz oscillator
Date: Thu, 14 Nov 2024 00:18:20 +0000
Organization: A noiseless patient Spider
Lines: 458
Message-ID: <t5fajjdteskfftvkf84iqsp2vc4b9ta5kj@4ax.com>
References: <vglt5t$30a3$1@nnrp.usenet.blueworldhosting.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 14 Nov 2024 01:18:38 +0100 (CET)
Injection-Info: dont-email.me; posting-host="fd890753a53d1d0aed83ea60e21cb6a4";
	logging-data="2595188"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18zqflSYmFtM4jVYwURxMQh"
User-Agent: ForteAgent/8.00.32.1272
Cancel-Lock: sha1:DV+LeruRMOT0Y3ca0S/oz+bvYY0=
Bytes: 15763

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

>This is the simplest circuit I can come up with.
>Harmonics are more than 80dB down in simulation.
>FFT the last 30 seconds.
>There is only one harmonic stopping me claiming 90dB but the exact FFT result can depend
>on exactly how much output is selected for the FFT. You may see different results.
>
>If a prototype is ever built, attention to the type and quality of the capacitors used will be needed.
>Electrolytics are not intended. Put C1 and C2 near U1 supply pins.
>Also pay attention to the stability of +/- 6V.
>It would be nice to have a single 12V rail version but so far I can't get it to work.
>
>R1 and R2 and probably R7 should be easily changeable.
>R3 should be 220 ohm ten turn. R9 should be 1M ohm ten turn in series with 470k.
>
>I don't fully understand why the DC stabilization circuit through U2B achieves what it does
>and this makes me concerned about whether a real circuit would have the same behaviour.
>It was added when I noticed that the diodes D1 and D2 weren't contributing equally so I
>decided to try to derive a DC correction signal. This was originally connected to the FET source
>and then to R13. Since this is a DC correction signal I decided to try out the effect of
>connecting it to U1 Vocm and was amazed that this works as well as it does.
>If you disconnect R5, harmonics will not be more than 50dB down because D1 and D2 are no
>longer providing stable and equal contributions to the level control feedback.
>
>If you need even better performance then the circuit referenced by Bill Sloman can be used.
>https://www.google.com/search?q=AN132+purity
>NSL-32SR3 is not expensive and simulation models exist but LT1468 is expensive.
>
>Other references
>
>https://www.google.com/search?&q=The+field+effect+transistor+as+a+voltage+controlled+resistor
>
>https://www.google.com/search?&q=sine+wave+oscillator&udm=2
>
>
>Version 4
>SHEET 1 2196 932
>WIRE -64 -672 -96 -672
>WIRE 48 -672 0 -672
>WIRE -96 -576 -96 -672
>WIRE -64 -576 -96 -576
>WIRE 48 -576 48 -672
>WIRE 48 -576 16 -576
>WIRE -32 -464 -32 -480
>WIRE 48 -448 48 -576
>WIRE 48 -448 0 -448
>WIRE -96 -432 -96 -576
>WIRE -64 -432 -96 -432
>WIRE 160 -416 0 -416
>WIRE 208 -416 160 -416
>WIRE 336 -416 288 -416
>WIRE 400 -416 336 -416
>WIRE 512 -416 400 -416
>WIRE 624 -416 512 -416
>WIRE -96 -384 -96 -432
>WIRE -32 -384 -32 -400
>WIRE 48 -368 48 -448
>WIRE 336 -368 336 -416
>WIRE 160 -352 160 -416
>WIRE 400 -352 400 -416
>WIRE 512 -288 512 -416
>WIRE 624 -288 624 -416
>WIRE -96 -272 -96 -304
>WIRE -96 -272 -192 -272
>WIRE -96 -240 -96 -272
>WIRE 48 -240 48 -288
>WIRE 160 -240 160 -288
>WIRE 336 -240 336 -288
>WIRE 400 -240 400 -288
>WIRE -192 -176 -192 -272
>WIRE -224 -128 -256 -128
>WIRE -96 -128 -96 -160
>WIRE -96 -128 -128 -128
>WIRE -80 -128 -96 -128
>WIRE 144 -128 -80 -128
>WIRE 288 -128 224 -128
>WIRE 352 -128 288 -128
>WIRE 512 -128 512 -224
>WIRE 512 -128 432 -128
>WIRE -256 -48 -256 -128
>WIRE -208 -48 -256 -48
>WIRE -80 -48 -80 -128
>WIRE -80 -48 -128 -48
>WIRE 288 -16 288 -128
>WIRE 288 -16 64 -16
>WIRE 352 -16 288 -16
>WIRE 512 -16 512 -128
>WIRE 512 -16 432 -16
>WIRE -256 0 -256 -48
>WIRE 144 48 144 32
>WIRE -240 96 -320 96
>WIRE -176 96 -240 96
>WIRE 64 96 64 -16
>WIRE 112 96 64 96
>WIRE 512 96 512 -16
>WIRE 512 96 272 96
>WIRE 16 128 -48 128
>WIRE 112 128 16 128
>WIRE -320 144 -320 96
>WIRE 624 144 624 -224
>WIRE 656 144 624 144
>WIRE 768 144 720 144
>WIRE 848 144 768 144
>WIRE -176 160 -176 96
>WIRE 16 160 16 128
>WIRE 112 160 64 160
>WIRE 624 160 624 144
>WIRE 624 160 272 160
>WIRE 144 224 144 208
>WIRE 848 240 848 144
>WIRE 16 256 16 224
>WIRE 64 272 64 160
>WIRE 160 272 64 272
>WIRE 288 272 160 272
>WIRE 400 272 352 272
>WIRE 512 272 512 96
>WIRE 512 272 480 272
>WIRE 64 288 64 272
>WIRE 160 288 160 272
>WIRE -320 320 -320 224
>WIRE -320 320 -400 320
>WIRE -400 336 -400 320
>WIRE -320 336 -320 320
>WIRE -176 336 -176 224
>WIRE -176 336 -320 336
>WIRE -48 336 -48 128
>WIRE 64 384 64 368
>WIRE 160 384 160 352
>WIRE 160 384 64 384
>WIRE -320 416 -320 336
>WIRE 64 416 64 384
>WIRE 848 416 848 320
>WIRE -176 432 -176 336
>WIRE 192 480 144 480
>WIRE 304 480 272 480
>WIRE 384 480 368 480
>WIRE 512 480 512 272
>WIRE 624 480 624 160
>WIRE 288 576 288 560
>WIRE -320 592 -320 496
>WIRE -240 592 -320 592
>WIRE -176 592 -176 496
>WIRE -176 592 -240 592
>WIRE 384 592 384 480
>WIRE 384 592 320 592
>WIRE 624 592 624 544
>WIRE 624 592 384 592
>WIRE -48 608 -48 416
>WIRE 0 608 -48 608
>WIRE 32 608 0 608
>WIRE 144 608 144 480
>WIRE 144 608 112 608
>WIRE 208 608 144 608
>WIRE 256 608 208 608
>WIRE 432 624 320 624
>WIRE 512 624 512 544
>WIRE 512 624 432 624
>WIRE 624 624 624 592
>WIRE 704 624 624 624
>WIRE -48 656 -48 608
>WIRE 0 656 0 608
>WIRE 288 656 288 640
>WIRE 512 656 512 624
>WIRE 704 656 704 624
>WIRE 432 672 432 624
>WIRE 624 672 624 624
>WIRE -48 768 -48 720
>WIRE 0 768 0 720
>WIRE 0 768 -48 768
>WIRE 432 768 432 736
>WIRE 512 768 512 736
>WIRE 512 768 432 768
>WIRE 624 768 624 736
>WIRE 624 768 512 768
>WIRE 704 768 704 736
>WIRE 704 768 624 768
>WIRE -48 800 -48 768
>WIRE 432 800 432 768
>FLAG -400 336 0
========== REMAINDER OF ARTICLE TRUNCATED ==========