Re: Random thoughts on sinewave oscillators

"Cursitor Doom" <cd999666@notformail.com> wrote in message news:veuirv$3cmo3$10@dont-email.me...

On Fri, 18 Oct 2024 15:59:09 -0400, Edward Rawde wrote:
>

"Cursitor Doom" <cd999666@notformail.com> wrote in message
news:veucs2$3cmo3$9@dont-email.me...

On Fri, 18 Oct 2024 14:20:48 -0400, Edward Rawde wrote:
>

"Cursitor Doom" <cd999666@notformail.com> wrote in message
news:veu7kt$3cmo3$8@dont-email.me...

On Fri, 18 Oct 2024 13:47:02 -0400, Edward Rawde wrote:
>

"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:

>

...

>
Without doubt, it's the trickiest aspect of the design. Definitely do-able
though. Let us know how you get on.
>

Ok. This simple circuit is based on the circuit you can find here.

https://electronics.stackexchange.com/questions/697687/how-to-control-the-amplitude-of-a-wien-bridge-oscillator

It produces a something wave.
I wouldn't call it sine but at least it's not clipping.
What's going on here?

Version 4
SHEET 1 2196 916
WIRE -160 -160 -256 -160
WIRE -16 -160 -160 -160
WIRE 160 -160 -16 -160
WIRE 400 -160 224 -160
WIRE -160 -144 -160 -160
WIRE -256 -128 -256 -160
WIRE 400 -128 400 -160
WIRE -16 -80 -16 -160
WIRE -256 -32 -256 -64
WIRE -160 -32 -160 -64
WIRE -160 -32 -256 -32
WIRE -48 -32 -160 -32
WIRE 112 -32 48 -32
WIRE 208 -32 192 -32
WIRE 272 -32 208 -32
WIRE 400 -32 400 -48
WIRE 400 -32 352 -32
WIRE -352 32 -480 32
WIRE 128 32 -352 32
WIRE 208 64 208 -32
WIRE 208 64 48 64
WIRE -480 80 -480 32
WIRE 128 96 128 32
WIRE -352 112 -352 32
WIRE 48 112 48 64
WIRE 96 112 48 112
WIRE 384 128 160 128
WIRE 400 128 400 -32
WIRE 400 128 384 128
WIRE 480 128 400 128
WIRE 544 128 480 128
WIRE 96 144 -80 144
WIRE -80 224 -80 144
WIRE 16 224 -80 224
WIRE 176 224 16 224
WIRE 256 224 240 224
WIRE 384 224 384 128
WIRE 384 224 336 224
WIRE -80 240 -80 224
WIRE 16 240 16 224
WIRE -480 320 -480 160
WIRE -480 320 -560 320
WIRE -560 336 -560 320
WIRE -480 336 -480 320
WIRE -352 336 -352 176
WIRE -352 336 -480 336
WIRE -336 336 -352 336
WIRE -256 336 -256 -32
WIRE -256 336 -336 336
WIRE -80 336 -80 320
WIRE -80 336 -256 336
WIRE 16 336 16 304
WIRE 16 336 -80 336
WIRE -480 464 -480 336
WIRE -336 496 -336 336
WIRE -480 656 -480 544
WIRE -336 656 -336 560
WIRE -336 656 -480 656
WIRE 128 656 128 160
WIRE 128 656 -336 656
FLAG 480 128 output
FLAG -560 336 0
DATAFLAG -432 32 "round(($)*100)/100"
DATAFLAG 64 -32 "round(($)*100)/100"
DATAFLAG 240 -32 "round(($)*100)/100"
DATAFLAG 64 -160 "round(($)*100)/100"
DATAFLAG 288 -160 "round(($)*100)/100"
SYMBOL voltage -480 64 R0
WINDOW 123 0 0 Left 0
WINDOW 39 10 135 Left 2
WINDOW 0 12 7 Left 2
WINDOW 3 15 104 Left 2
SYMATTR SpiceLine Rser=0.1
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL res 352 208 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 12k
SYMBOL cap 240 208 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 15n
SYMBOL cap 32 304 R180
WINDOW 0 -33 54 Left 2
WINDOW 3 -49 18 Left 2
SYMATTR InstName C2
SYMATTR Value 15n
SYMBOL polcap -368 112 R0
SYMATTR InstName C4
SYMATTR Value 100�
SYMBOL OpAmps\LT1057 128 64 R0
SYMATTR InstName U2
SYMBOL res -176 -160 R0
SYMATTR InstName R6
SYMATTR Value 47k
SYMBOL res 208 -48 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R7
SYMATTR Value 4.7k
SYMBOL res 368 -48 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 13k
SYMBOL diode 160 -144 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL res 384 -144 R0
SYMATTR InstName R9
SYMATTR Value 4.7k
SYMBOL njf 48 -80 R90
WINDOW 0 -38 17 VRight 2
WINDOW 3 -7 -47 VRight 2
SYMATTR InstName J1
SYMATTR Value 2N3819
SYMBOL voltage -480 448 R0
WINDOW 123 0 0 Left 0
WINDOW 39 10 135 Left 2
WINDOW 0 12 7 Left 2
WINDOW 3 15 104 Left 2
SYMATTR SpiceLine Rser=0.1
SYMATTR InstName V2
SYMATTR Value 12
SYMBOL polcap -352 496 R0
SYMATTR InstName C5
SYMATTR Value 100�
SYMBOL res -96 224 R0
SYMATTR InstName R2
SYMATTR Value 12k
SYMBOL polcap -240 -64 R180
WINDOW 0 -35 53 Left 2
WINDOW 3 -47 17 Left 2
SYMATTR InstName C3
SYMATTR Value 10�
TEXT -464 352 Left 2 !.tran 10