Here's a variation on the variation by Bill Sloman with sample/hold instead of multi phase rectifier.
Performance does not seem to be any better so unless someone can tell me how to design a better practical sample/hold circuit this is probably my final post on the subject of sinewave oscillators. (Which will probably be a relief to some people.)
Operation should be fairly self explanatory. It uses a ringing transformer to open the sample gate for about 10us.
This version uses a comparator for more stable timing characteristics.
D2 etc keeps the comparator output below 40V.
Simulation is very slow for the first few cycles but then speeds up to about 7 ms/s in LTSpice 24.1.7
At least two lines will need to be unwrapped below.
Version 4.1 SHEET 1 3240 2548 WIRE 80 -208 -288 -208 WIRE 800 -208 160 -208 WIRE -288 -96 -288 -208 WIRE 80 -96 -288 -96 WIRE 400 -96 160 -96 WIRE -288 32 -288 -96 WIRE -176 32 -288 32 WIRE -32 32 -96 32 WIRE 48 32 -32 32 WIRE 208 32 128 32 WIRE 256 32 208 32 WIRE 400 32 400 -96 WIRE 400 32 320 32 WIRE 464 32 400 32 WIRE 608 32 544 32 WIRE 656 32 608 32 WIRE 800 32 800 -208 WIRE 800 32 720 32 WIRE 848 32 800 32 WIRE 992 32 928 32 WIRE 1040 32 992 32 WIRE 1184 32 1120 32 WIRE -752 48 -816 48 WIRE -624 48 -688 48 WIRE -288 144 -288 32 WIRE -176 144 -288 144 WIRE 208 144 208 32 WIRE 256 144 208 144 WIRE 608 144 608 32 WIRE 656 144 608 144 WIRE 992 144 992 32 WIRE 1040 144 992 144 WIRE -816 160 -816 48 WIRE -752 160 -816 160 WIRE -624 160 -624 48 WIRE -624 160 -672 160 WIRE -32 160 -32 32 WIRE -32 160 -112 160 WIRE 400 160 400 32 WIRE 400 160 320 160 WIRE 800 160 800 32 WIRE 800 160 720 160 WIRE 1184 160 1184 32 WIRE 1184 160 1104 160 WIRE 1216 160 1184 160 WIRE -176 176 -288 176 WIRE 256 176 224 176 WIRE 656 176 624 176 WIRE 1040 176 1008 176 WIRE 224 208 224 176 WIRE 624 208 624 176 WIRE 1008 208 1008 176 WIRE -1968 224 -1968 144 WIRE -1008 272 -1104 272 WIRE -816 272 -816 160 WIRE -816 272 -944 272 WIRE -736 272 -816 272 WIRE -624 288 -624 160 WIRE -624 288 -672 288 WIRE -544 288 -624 288 WIRE -416 288 -480 288 WIRE -288 288 -288 176 WIRE -288 288 -336 288 WIRE -208 288 -288 288 WIRE 208 288 -128 288 WIRE 400 288 400 160 WIRE 400 288 208 288 WIRE -736 304 -816 304 WIRE -816 336 -816 304 WIRE -32 352 -32 160 WIRE -32 352 -288 352 WIRE -1968 400 -1968 304 WIRE -1856 400 -1968 400 WIRE -1664 400 -1776 400 WIRE -32 400 -1600 400 WIRE 208 400 208 288 WIRE 208 400 -32 400 WIRE 800 480 800 160 WIRE 800 480 -128 480 WIRE -1968 496 -1968 400 WIRE -1968 496 -2304 496 WIRE -2432 544 -2432 496 WIRE -2304 560 -2304 496 WIRE -2240 560 -2304 560 WIRE -2144 560 -2176 560 WIRE -1360 576 -1360 480 WIRE -1968 640 -1968 496 WIRE 240 656 48 656 WIRE 1040 656 848 656 WIRE -2304 672 -2304 560 WIRE -2256 672 -2304 672 WIRE -2144 688 -2144 560 WIRE -2144 688 -2192 688 WIRE -2032 688 -2144 688 WIRE -1360 688 -1360 656 WIRE -1104 688 -1104 272 WIRE -1104 688 -1360 688 WIRE -2432 704 -2432 624 WIRE -2256 704 -2432 704 WIRE 848 736 848 656 WIRE 896 736 848 736 WIRE 48 752 48 656 WIRE 96 752 48 752 WIRE 1040 752 1040 656 WIRE 1040 752 960 752 WIRE 1136 752 1040 752 WIRE 1296 752 1136 752 WIRE 240 768 240 656 WIRE 240 768 160 768 WIRE 384 768 240 768 WIRE 576 768 480 768 WIRE 656 768 576 768 WIRE 688 768 656 768 WIRE 864 768 784 768 WIRE 896 768 864 768 WIRE -32 784 -32 400 WIRE 32 784 -32 784 WIRE 96 784 32 784 WIRE -2432 832 -2432 704 WIRE -2432 832 -2544 832 WIRE 864 848 864 768 WIRE -2544 864 -2544 832 WIRE -2432 864 -2432 832 WIRE 464 864 464 816 WIRE 560 864 464 864 WIRE 592 864 560 864 WIRE 704 864 704 816 WIRE 704 864 592 864 WIRE -1360 880 -1360 688 WIRE -1968 928 -1968 736 WIRE -1424 928 -1968 928 WIRE 128 928 128 912 WIRE -2544 960 -2544 928 WIRE 864 992 864 912 WIRE -2432 1008 -2432 944 WIRE 128 1040 128 1008 WIRE 128 1040 16 1040 WIRE 16 1056 16 1040 WIRE -2160 1152 -2160 1040 WIRE -1664 1152 -1664 1040 WIRE 16 1152 16 1120 WIRE -1968 1200 -1968 928 WIRE -1968 1200 -2096 1200 WIRE -1904 1200 -1968 1200 WIRE -1728 1200 -1904 1200 WIRE 128 1200 128 1040 WIRE 128 1200 0 1200 WIRE 272 1200 192 1200 WIRE 320 1200 272 1200 WIRE 416 1200 400 1200 WIRE 432 1200 416 1200 WIRE 560 1200 560 864 WIRE 560 1200 512 1200 WIRE -2480 1216 -2480 1184 WIRE -2480 1216 -2528 1216 WIRE -2528 1232 -2528 1216 WIRE -1360 1232 -1360 976 WIRE 0 1232 0 1200 WIRE 128 1232 128 1200 WIRE 192 1232 192 1200 WIRE 272 1232 272 1200 WIRE 560 1232 560 1200 WIRE -2480 1248 -2480 1216 WIRE 416 1248 416 1200 WIRE -1664 1280 -1664 1248 WIRE -1424 1280 -1664 1280 WIRE -2160 1296 -2160 1248 WIRE -2160 1296 -2240 1296 WIRE -2240 1344 -2240 1296 WIRE 0 1344 0 1296 WIRE 128 1344 128 1312 WIRE 128 1344 0 1344 WIRE 192 1344 192 1312 WIRE 240 1344 192 1344 WIRE 272 1344 272 1296 WIRE 272 1344 240 1344 WIRE 416 1344 416 1312 WIRE 416 1344 272 1344 WIRE 560 1344 560 1312 WIRE 560 1344 416 1344 WIRE 656 1344 656 768 WIRE 656 1344 560 1344 WIRE -1664 1360 -1664 1280 WIRE -288 1392 -288 352 WIRE -128 1392 -128 480 WIRE 128 1408 128 1344 WIRE 144 1408 128 1408 WIRE 240 1408 240 1344 WIRE 240 1408 208 1408 WIRE -1360 1440 -1360 1328 WIRE -1136 1440 -1232 1440 WIRE -976 1440 -1072 1440 WIRE -2240 1488 -2240 1424 WIRE -1664 1504 -1664 1440 WIRE -16 1504 -16 1440 WIRE -1232 1520 -1232 1440 WIRE -1184 1520 -1232 1520 WIRE -1072 1520 -1120 1520 WIRE -976 1520 -976 1440 WIRE -976 1520 -992 1520 WIRE -128 1536 -128 1472 WIRE -48 1536 -128 1536 WIRE 128 1552 128 1408 WIRE 128 1552 32 1552 WIRE -288 1568 -288 1472 WIRE -48 1568 -288 1568 WIRE 128 1568 128 1552 WIRE 160 1568 128 1568 WIRE 240 1568 224 1568 WIRE 320 1568 240 1568 WIRE 320 1584 320 1568 WIRE 240 1600 240 1568 WIRE -288 1616 -288 1568 WIRE -128 1616 -128 1536 WIRE 128 1616 128 1568 WIRE -976 1632 -976 1520 WIRE -976 1632 -1056 1632 WIRE -832 1632 -976 1632 WIRE -752 1632 -832 1632 WIRE -624 1632 -672 1632 WIRE -496 1632 -560 1632 WIRE -2160 1648 -2160 1296 WIRE -1648 1648 -2160 1648 WIRE -1232 1648 -1232 1520 WIRE -1232 1648 -1568 1648 WIRE -1120 1648 -1232 1648 WIRE -1024 1664 -1056 1664 WIRE -32 1680 -32 1600 WIRE -16 1680 -16 1600 WIRE -16 1680 -32 1680 WIRE -16 1696 -16 1680 WIRE 128 1696 128 1680 WIRE 128 1696 -16 1696 WIRE 240 1696 240 1664 WIRE 240 1696 128 1696 WIRE 320 1696 320 1664 WIRE 320 1696 240 1696 WIRE -1904 1712 -1904 1200 WIRE -832 1712 -832 1632 WIRE -288 1728 -288 1696 WIRE -128 1728 -128 1696 WIRE -16 1728 -16 1696 WIRE -2160 1760 -2160 1648 WIRE -1968 1760 -2160 1760 WIRE -1024 1776 -1024 1664 WIRE -1904 1888 -1904 1808 WIRE -832 1920 -832 1792 WIRE 1296 1920 1296 752 WIRE 1296 1920 -832 1920 FLAG 224 208 0 FLAG 624 208 0 FLAG -1088 1616 vcc FLAG -1088 1680 vee FLAG -2528 1232 0 FLAG -2480 1104 vcc FLAG -2480 1328 vee FLAG -144 128 vcc FLAG -144 192 vee FLAG 288 128 vcc FLAG 288 192 vee FLAG 688 128 vcc FLAG 688 192 vee FLAG -2224 656 vcc FLAG -1968 144 vcc FLAG -2224 720 vee FLAG -1360 480 vcc FLAG -2432 496 vcc FLAG -2432 1008 0 FLAG -1360 1440 0 FLAG -704 256 vcc FLAG -704 320 vee FLAG -816 336 0 FLAG -1664 1504 vee FLAG -1904 1888 0 FLAG -1664 1040 vcc FLAG -2160 1040 vcc FLAG -1024 1776 0 FLAG -2544 960 0 FLAG -496 1632 vee FLAG -2240 1488 vee FLAG 1008 208 0 FLAG 1216 160 vout FLAG 1072 128 vcc FLAG 1072 192 vee FLAG 128 912 vcc FLAG 592 864 gate FLAG 576 768 source FLAG 16 1152 0 FLAG 864 992 0 FLAG 928 720 vcc FLAG 928 784 vee FLAG 128 736 vcc FLAG 128 800 vee FLAG -16 1728 0 FLAG -16 1440 vcc FLAG -128 1728 0 FLAG -288 1728 0 FLAG 1136 752 hold FLAG 32 784 sample SYMBOL res -80 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 10K SYMBOL res 144 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 16K SYMBOL res 560 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 16K SYMBOL cap 320 16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 10n SYMBOL cap 720 16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 10n SYMBOL res 176 -224 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 10K SYMBOL res 176 -80 M270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R5 SYMATTR Value 82k SYMBOL cap -1072 1424 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1000n SYMBOL res -768 1648 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R10 SYMATTR Value 470k SYMBOL res -848 1696 R0 SYMATTR InstName R11 SYMATTR Value 68k SYMBOL voltage -2480 1088 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 15 SYMBOL voltage -2480 1232 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 15 SYMBOL OpAmps\\LT1679 -144 160 R0 SYMATTR InstName U5 SYMBOL OpAmps\\LT1679 288 160 R0 SYMATTR InstName U6 SYMBOL OpAmps\\LT1679 688 160 R0 SYMATTR InstName U8 SYMBOL res -112 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res -320 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 560 SYMBOL cap -480 272 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C8 SYMATTR Value 1000n SYMBOL res -1088 1536 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R6 SYMATTR Value 100k SYMBOL cap -1120 1504 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 10000n SYMBOL pnp -2032 736 M180 WINDOW 3 84 0 Left 2 SYMATTR Value 2N3906 SYMATTR InstName Q4 SYMBOL res -1984 208 R0 SYMATTR InstName R12 SYMATTR Value 82k SYMBOL res -1760 384 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R25 SYMATTR Value 2.7Meg SYMBOL cap -2176 544 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C7 SYMATTR Value 10p SYMBOL npn -2096 1152 M0 SYMATTR InstName Q1A SYMATTR Value NSS40301MDR2G SYMBOL npn -1728 1152 R0 SYMATTR InstName Q1B SYMATTR Value NSS40301MDR2G SYMBOL npn -1424 1232 R0 SYMATTR InstName Q2B SYMATTR Value NSS40301MDR2G SYMBOL npn -1968 1712 R0 SYMATTR InstName Q2A SYMATTR Value NSS40301MDR2G SYMBOL res -1552 1632 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R28 SYMATTR Value 68k SYMBOL res -1376 560 R0 SYMATTR InstName R29 SYMATTR Value 100k SYMBOL res -2448 528 R0 SYMATTR InstName R32 SYMATTR Value 10k SYMBOL res -2448 848 R0 SYMATTR InstName R33 SYMATTR Value 15k SYMBOL cap -944 256 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C12 SYMATTR Value 1000n SYMBOL res -656 144 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 14k SYMBOL cap -688 32 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 10p SYMBOL cap -1600 384 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C6 SYMATTR Value 100n SYMBOL res -1648 1456 R180 WINDOW 0 31 76 Left 2 WINDOW 3 31 40 Left 2 SYMATTR InstName R17 SYMATTR Value 22k SYMBOL OpAmps\\LT1679 -704 288 R0 SYMATTR InstName U2 SYMBOL OpAmps\\LT1679 -1088 1648 M0 SYMATTR InstName U3 SYMBOL OpAmps\\LT1679 -2224 688 R0 SYMATTR InstName U4 SYMBOL cap -2560 864 R0 SYMATTR InstName C9 SYMATTR Value 10n SYMBOL res -2224 1440 R180 WINDOW 0 31 76 Left 2 WINDOW 3 31 40 Left 2 SYMATTR InstName R20 SYMATTR Value 27k SYMBOL npn -1424 880 R0 SYMATTR InstName Q3 SYMATTR Value 2N3904 SYMBOL diode -624 1648 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D7 SYMATTR Value 1N914 SYMBOL res 944 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R26 SYMATTR Value 10k SYMBOL OpAmps\\LT1679 1072 160 R0 SYMATTR InstName U7 SYMBOL res 1136 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R27 SYMATTR Value 10k SYMBOL ind2 112 1216 R0 WINDOW 0 -43 36 Left 2 WINDOW 3 -46 73 Left 2 SYMATTR InstName L1 SYMATTR Value 1m SYMATTR Type ind SYMATTR SpiceLine Rser=0.45 SYMBOL ind2 208 1328 R180 WINDOW 0 -29 74 Left 2 WINDOW 3 -38 43 Left 2 SYMATTR InstName L2 SYMATTR Value 1m SYMATTR Type ind SYMATTR SpiceLine Rser=0.45 SYMBOL res 112 912 R0 SYMATTR InstName R30 SYMATTR Value 33 SYMBOL cap -16 1232 R0 SYMATTR InstName C11 SYMATTR Value 33n SYMBOL res 544 1216 R0 SYMATTR InstName R31 SYMATTR Value 220 SYMBOL nmos 784 816 M270 WINDOW 0 19 -9 VLeft 2 WINDOW 3 75 84 VLeft 2 SYMATTR InstName M1 SYMATTR Value RSF015N06 SYMBOL nmos 384 816 R270 WINDOW 0 19 -9 VLeft 2 WINDOW 3 75 84 VLeft 2 SYMATTR InstName M2 SYMATTR Value RSF015N06 SYMBOL cap 0 1056 R0 SYMATTR InstName C13 SYMATTR Value 1000n SYMBOL cap 256 1232 R0 SYMATTR InstName C14 SYMATTR Value 33n SYMBOL res 416 1184 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R35 SYMATTR Value 470 SYMBOL cap 848 848 R0 SYMATTR InstName C15 SYMATTR Value 100n SYMBOL res 528 1184 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R37 SYMATTR Value 1k SYMBOL diode 432 1312 R180 WINDOW 0 23 5 Left 2 WINDOW 3 -102 2 Left 2 SYMATTR InstName D9 SYMATTR Value BAT54HY SYMBOL cap 144 1392 M90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C0 SYMATTR Value 33p SYMBOL OpAmps\\LT1679 928 752 R0 SYMATTR InstName U9 SYMBOL OpAmps\\LT1220 128 704 R0 SYMATTR InstName U10 SYMBOL Comparators\\LT1011 -16 1552 R0 SYMATTR InstName U1 SYMBOL res -304 1376 R0 SYMATTR InstName R13 SYMATTR Value 10k SYMBOL res -304 1600 R0 SYMATTR InstName R14 SYMATTR Value 10k SYMBOL res -144 1376 R0 SYMATTR InstName R15 SYMATTR Value 10k SYMBOL res -144 1600 R0 SYMATTR InstName R16 SYMATTR Value 10k SYMBOL diode 144 1680 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value 1N914 SYMBOL diode 160 1584 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D2 SYMATTR Value 1N914 SYMBOL cap 224 1600 R0 SYMATTR InstName C10 SYMATTR Value 33n SYMBOL res 304 1568 R0 SYMATTR InstName R18 SYMATTR Value 2.2k TEXT -2792 1560 Left 2 !.tran 0 6 0 1u uic TEXT -2792 1504 Left 2 !.options plotwinsize=0 numdgt=15 TEXT -1720 8 Left 2 ;Low distortion 1KHz oscillator. ER, JM, BS.\n30 March 2025 - 24 April 2025\nS/H by ER but no better than multi phase rectifier. TEXT -2736 48 Left 2 !.MODEL NSS40301MDR2G NPN\n+is=6.87023e-12 bf=445.496 nf=1.08926 vaf=60.529\n+ikf=7.23313 ise=2.38192e-09 ne=4 br=23.6872\n+nr=1.10701 var=8.89608 ikr=1.25064 isc=1e-16 \n+nc=1.13174 rb=905.334,irb=2.30349e-07 rbm=1e-10\n+re=0.00600548 rc=0.0300274 xtb=1.2219 xti=4,\n+eg=1.05 cje=3.80477e-10 vje=0.912237 mje=0.397194,\n+tf=5.90916e-10,xtf=0.0998483,vtf=7.09172,itf=0.010481,\n+cjc=8.35472e-11 vjc=0.702862 mjc=0.43477 xcjc=0.899998\n+fc=0.414631 cjs=0 vjs=0.75 mjs=0.5 \n+tr=5.64658e-08 ptf=0,kf=0 af=1 TEXT 216 1160 Top 2 !K1 L1 L2 0.98 TEXT 136 1144 Left 2 ;Murata 78601/8MC TEXT 208 1432 Left 2 ;Interwinding capacitance.\nNot a separate component.