Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Bill Sloman <bill.sloman@ieee.org>
Newsgroups: sci.electronics.design
Subject: Current mirror version of the lowish distortion 1kHz sine wave
 osillator
Date: Wed, 15 Jan 2025 23:33:55 +1100
Organization: A noiseless patient Spider
Lines: 805
Message-ID: <vm89vp$2ulja$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 15 Jan 2025 13:34:04 +0100 (CET)
Injection-Info: dont-email.me; posting-host="cf1ab6d6bb42e82f1d7762193412dbe4";
	logging-data="3102314"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX197IH7WteumKajDcbwvJgFZFImgAJJ/wiM="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:nZYPgGzYEZZovmWj+LSZ/HS4hc4=
X-Antivirus: Norton (VPS 250114-22, 15/1/2025), Outbound message
X-Antivirus-Status: Clean
Content-Language: en-US
Bytes: 22786

This just reworks my circuit to use a controllable asymmetric current 
mirror instead of the FET for gain control. I take the feedback from the 
full wave rectifier and switch every half-cycle to reconstruct a 
variable amplitude sine wave to control the output amplitude. It does 
use a lot of components, but it strikes me as fairly comprehensible.

R30 isn't a real part - it's just there to let me do an FFT on the 
correction signal.

The circuit just copes with worst case capacitors - 15.15nF and 14.85nF 
- at C5 and C6, as it was intended to do. Using a trim pot to take out 
component tolerances would let you get away with a smaller correction 
signal injecting smaller doses of the odd harmonics.

The circuit does cry out for monolithic dual transisors.The On-Semi
NST45010MW6T1G pnp and the
NST45011MW6T1G npn parts are cheap and widely available.

Version 4
SHEET 1 3608 920
WIRE -1360 -2400 -1984 -2400
WIRE -1200 -2400 -1360 -2400
WIRE -1104 -2400 -1200 -2400
WIRE -736 -2400 -1104 -2400
WIRE -320 -2400 -736 -2400
WIRE 208 -2400 -320 -2400
WIRE 336 -2400 208 -2400
WIRE 576 -2400 336 -2400
WIRE -736 -2384 -736 -2400
WIRE 208 -2384 208 -2400
WIRE -320 -2368 -320 -2400
WIRE 3376 -2272 -1616 -2272
WIRE 880 -2192 -1776 -2192
WIRE -1360 -2160 -1360 -2400
WIRE -736 -2160 -736 -2320
WIRE -656 -2160 -736 -2160
WIRE -320 -2160 -320 -2304
WIRE -176 -2160 -320 -2160
WIRE 208 -2144 208 -2320
WIRE 336 -2144 208 -2144
WIRE -1200 -2112 -1200 -2400
WIRE -1360 -2048 -1360 -2080
WIRE -320 -2000 -320 -2160
WIRE -736 -1984 -736 -2160
WIRE -1776 -1968 -1776 -2192
WIRE 336 -1968 336 -2144
WIRE 576 -1968 576 -2400
WIRE -1360 -1920 -1360 -1968
WIRE -1200 -1920 -1200 -2032
WIRE 1952 -1920 1744 -1920
WIRE 2160 -1920 1952 -1920
WIRE -1616 -1904 -1616 -2272
WIRE 1376 -1904 1072 -1904
WIRE 1536 -1904 1376 -1904
WIRE 336 -1888 336 -1904
WIRE -1280 -1872 -1296 -1872
WIRE -1264 -1872 -1280 -1872
WIRE -576 -1872 -912 -1872
WIRE -32 -1872 -496 -1872
WIRE 1744 -1872 1744 -1920
WIRE 1072 -1856 1072 -1904
WIRE 1952 -1824 1904 -1824
WIRE 2160 -1824 2160 -1920
WIRE 2160 -1824 2032 -1824
WIRE -128 -1808 -272 -1808
WIRE -32 -1808 -32 -1872
WIRE -32 -1808 -64 -1808
WIRE -1776 -1792 -1776 -1888
WIRE -1776 -1792 -2064 -1792
WIRE -1280 -1792 -1280 -1872
WIRE -1200 -1792 -1200 -1824
WIRE -1200 -1792 -1280 -1792
WIRE -912 -1792 -912 -1872
WIRE -864 -1792 -912 -1792
WIRE -544 -1792 -784 -1792
WIRE -1200 -1776 -1200 -1792
WIRE 576 -1776 576 -1904
WIRE 768 -1776 576 -1776
WIRE 2160 -1776 2160 -1824
WIRE 2288 -1776 2160 -1776
WIRE 2432 -1776 2368 -1776
WIRE 2496 -1776 2432 -1776
WIRE 2800 -1776 2576 -1776
WIRE 2864 -1776 2800 -1776
WIRE 3088 -1776 2944 -1776
WIRE 1280 -1760 1232 -1760
WIRE 1536 -1760 1536 -1904
WIRE 1536 -1760 1360 -1760
WIRE -1776 -1728 -1776 -1792
WIRE -1360 -1728 -1360 -1824
WIRE -1360 -1728 -1520 -1728
WIRE -1264 -1728 -1360 -1728
WIRE -544 -1728 -544 -1792
WIRE 3088 -1728 3088 -1776
WIRE -1984 -1712 -1984 -2400
WIRE -272 -1712 -272 -1808
WIRE -128 -1712 -272 -1712
WIRE -32 -1712 -32 -1808
WIRE -32 -1712 -64 -1712
WIRE 2432 -1712 2432 -1776
WIRE -2064 -1696 -2064 -1792
WIRE -2016 -1696 -2064 -1696
WIRE -1840 -1680 -1952 -1680
WIRE -2016 -1664 -2064 -1664
WIRE 1648 -1648 1392 -1648
WIRE 2064 -1648 1648 -1648
WIRE -912 -1632 -912 -1792
WIRE -848 -1632 -912 -1632
WIRE -544 -1632 -544 -1648
WIRE -544 -1632 -784 -1632
WIRE 2624 -1632 2624 -1648
WIRE -1200 -1616 -1200 -1680
WIRE -1200 -1616 -1360 -1616
WIRE -1072 -1616 -1200 -1616
WIRE -912 -1616 -912 -1632
WIRE -912 -1616 -992 -1616
WIRE -272 -1616 -272 -1712
WIRE -144 -1616 -272 -1616
WIRE -32 -1616 -32 -1712
WIRE -32 -1616 -64 -1616
WIRE 2064 -1616 2064 -1648
WIRE 1392 -1600 1392 -1648
WIRE 1904 -1600 1904 -1824
WIRE 2032 -1600 1904 -1600
WIRE -2064 -1584 -2064 -1664
WIRE -544 -1584 -544 -1632
WIRE -512 -1584 -544 -1584
WIRE -432 -1584 -448 -1584
WIRE -272 -1584 -272 -1616
WIRE -272 -1584 -352 -1584
WIRE 1232 -1584 1232 -1760
WIRE 1360 -1584 1232 -1584
WIRE 2160 -1584 2160 -1776
WIRE 2160 -1584 2096 -1584
WIRE 2432 -1584 2432 -1632
WIRE 1536 -1568 1536 -1760
WIRE 1536 -1568 1424 -1568
WIRE 1584 -1568 1536 -1568
WIRE 1744 -1568 1744 -1808
WIRE 1744 -1568 1664 -1568
WIRE 1792 -1568 1744 -1568
WIRE 2000 -1568 1872 -1568
WIRE 2032 -1568 2000 -1568
WIRE -176 -1552 -176 -2160
WIRE 880 -1552 880 -2192
WIRE 912 -1552 880 -1552
WIRE 1072 -1552 1072 -1792
WIRE 1072 -1552 992 -1552
WIRE 1120 -1552 1072 -1552
WIRE 1328 -1552 1200 -1552
WIRE 1360 -1552 1328 -1552
WIRE -272 -1536 -272 -1584
WIRE -208 -1536 -272 -1536
WIRE 2800 -1536 2800 -1776
WIRE 2848 -1536 2800 -1536
WIRE 3088 -1536 3088 -1664
WIRE 3088 -1536 2912 -1536
WIRE -32 -1520 -32 -1616
WIRE -32 -1520 -144 -1520
WIRE 16 -1520 -32 -1520
WIRE 64 -1520 16 -1520
WIRE 112 -1520 64 -1520
WIRE 432 -1520 192 -1520
WIRE -208 -1504 -288 -1504
WIRE -1264 -1488 -1664 -1488
WIRE -656 -1472 -656 -2160
WIRE -912 -1456 -912 -1616
WIRE -688 -1456 -912 -1456
WIRE -288 -1456 -288 -1504
WIRE 256 -1456 144 -1456
WIRE 368 -1456 336 -1456
WIRE 496 -1456 368 -1456
WIRE 1392 -1456 1392 -1536
WIRE 1632 -1456 1392 -1456
WIRE 2064 -1456 2064 -1552
WIRE 2064 -1456 1632 -1456
WIRE 2432 -1456 2288 -1456
WIRE 2992 -1456 2432 -1456
========== REMAINDER OF ARTICLE TRUNCATED ==========