nonsense

At best it would surely require a very specific kind of toroidal core to make it work. But there is no real information given about the toroidal core at all. On the circuit it just says L1 100μH.

"john larkin" snipped-for-privacy@htigct.com wrote in message news: snipped-for-privacy@4ax.com...

If you make R3 12.3k you can have a sinewave for the first 300ms

Version 4.1 SHEET 1 3020 2548 WIRE -1184 160 -1264 160 WIRE -1008 160 -1104 160 WIRE -1984 320 -1984 288 WIRE -1984 320 -2032 320 WIRE -1760 320 -1840 320 WIRE -1648 320 -1680 320 WIRE -1584 320 -1648 320 WIRE -1456 320 -1504 320 WIRE -1392 320 -1456 320 WIRE -1264 320 -1264 160 WIRE -1264 320 -1312 320 WIRE -1184 320 -1264 320 WIRE -2032 336 -2032 320 WIRE -1008 336 -1008 160 WIRE -1008 336 -1120 336 WIRE -1984 352 -1984 320 WIRE -1184 352 -1232 352 WIRE -1232 384 -1232 352 WIRE -1648 400 -1648 320 WIRE -1456 400 -1456 320 WIRE -1008 400 -1008 336 WIRE -928 400 -1008 400 WIRE -848 400 -928 400 WIRE -1648 496 -1648 464 WIRE -1456 496 -1456 464 WIRE -1840 608 -1840 320 WIRE -1008 608 -1008 400 WIRE -1008 608 -1840 608 FLAG -2032 336 0 FLAG -1984 208 vcc FLAG -1984 432 vee FLAG -1152 304 vcc FLAG -1152 368 vee FLAG -928 400 output FLAG -1232 384 0 FLAG -1456 496 0 FLAG -1648 496 0 SYMBOL voltage -1984 192 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 15 SYMBOL voltage -1984 336 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 15 SYMBOL OpAmps\\LT1357 -1152 272 R0 SYMATTR InstName U1 SYMBOL res -1088 144 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 12.3k SYMBOL res -1296 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL res -1664 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 2.2k SYMBOL ind -1488 304 R90 WINDOW 0 5 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName L1 SYMATTR Value 100000n SYMATTR SpiceLine Rser=1m SYMBOL cap -1664 400 R0 SYMATTR InstName C1 SYMATTR Value 33n SYMBOL cap -1472 400 R0 SYMATTR InstName C2 SYMATTR Value 33n TEXT -1800 64 Left 2 !.tran 0 300m 0 1u startup TEXT -1800 8 Left 2 !.options plotwinsize=0 numdgt=15

A better inductor simulation along these lines may produce a sinewave untill the wind direction changes.

"Edward Rawde" snipped-for-privacy@invalid.invalid wrote in message news:1162v3c$28a0$ snipped-for-privacy@nnrp.usenet.blueworldhosting.com...

Like this, but only about 60dB down on harmonics.

Version 4.1 SHEET 1 3020 2548 WIRE -1184 160 -1264 160 WIRE -1008 160 -1104 160 WIRE -1984 320 -1984 288 WIRE -1984 320 -2032 320 WIRE -1760 320 -1840 320 WIRE -1648 320 -1680 320 WIRE -1584 320 -1648 320 WIRE -1456 320 -1504 320 WIRE -1392 320 -1456 320 WIRE -1264 320 -1264 160 WIRE -1264 320 -1312 320 WIRE -1184 320 -1264 320 WIRE -2032 336 -2032 320 WIRE -1008 336 -1008 160 WIRE -1008 336 -1120 336 WIRE -1984 352 -1984 320 WIRE -1184 352 -1232 352 WIRE -1232 384 -1232 352 WIRE -1648 400 -1648 320 WIRE -1456 400 -1456 320 WIRE -1008 400 -1008 336 WIRE -928 400 -1008 400 WIRE -848 400 -928 400 WIRE -1648 496 -1648 464 WIRE -1456 496 -1456 464 WIRE -1840 608 -1840 320 WIRE -1008 608 -1008 400 WIRE -1008 608 -1840 608 FLAG -2032 336 0 FLAG -1984 208 vcc FLAG -1984 432 vee FLAG -1152 304 vcc FLAG -1152 368 vee FLAG -928 400 output FLAG -1232 384 0 FLAG -1456 496 0 FLAG -1648 496 0 SYMBOL voltage -1984 192 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 15 SYMBOL voltage -1984 336 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 15 SYMBOL OpAmps\\LT1357 -1152 272 R0 SYMATTR InstName U1 SYMBOL res -1088 144 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 12.23k SYMBOL res -1296 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL res -1664 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 2.2k SYMBOL ind -1488 304 R90 WINDOW 0 5 56 VBottom 2 WINDOW 3 -47 56 VTop 2 SYMATTR InstName L1 SYMATTR Value Flux=100000n*tanh(5*x) SYMATTR SpiceLine Rser=1m SYMBOL cap -1664 400 R0 SYMATTR InstName C1 SYMATTR Value 33n SYMBOL cap -1472 400 R0 SYMATTR InstName C2 SYMATTR Value 33n TEXT -1800 64 Left 2 !.tran 0 2 0 1u startup TEXT -1800 8 Left 2 !.options plotwinsize=0 numdgt=15

I think R3 should have been 12.5k so perhaps calling it 12k5 is not a bad idea after all.

It's improbable that the opamp can output enough current to saturate that toroid. Q is pretty low.

I suspect that the author fine-tuned the opamp gain until he got a pretty stable sine wave. That tweaking process is a form of AGC.

The opamp slew rate might be the nonlinear gain-set element.

Ugly breadboard.

Those Aspencore sites have some really bad circuit examples.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

It is certainly nonsense. The amplitude control mechanism is the op amp running out of gain - running out of slew rate is just a manifestation that.

It's not a recipe for a low harmonic content sine wave, despite Edward Rawde's long held conviction that it is. Any number of people can be fond of bad ideas - religions depend on it - but it doesn't make them right.