Electrometer.asc

Version 4
SHEET 1 2884 3000
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WIRE 480 880 480 864
WIRE 720 880 720 864
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WIRE 880 896 864 896
WIRE 1072 896 1072 816
WIRE 1072 896 944 896
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WIRE 48 928 -16 928
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WIRE 672 944 640 944
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WIRE 624 1040 576 944
WIRE 672 1040 624 1040
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WIRE 480 1120 384 1120
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WIRE -272 1200 -512 1200
WIRE -160 1200 -160 1184
WIRE -160 1200 -272 1200
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WIRE -16 1200 -160 1200
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WIRE -880 1248 -912 1248
WIRE -816 1248 -880 1248
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WIRE -672 1248 -736 1248
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WIRE -384 1248 -672 1248
WIRE -352 1248 -352 1232
WIRE -304 1248 -352 1248
WIRE 1072 1248 1072 1008
WIRE 1072 1248 -304 1248
WIRE -352 1296 -384 1296
WIRE -912 1312 -912 1248
WIRE -640 1312 -912 1312
WIRE -576 1312 -640 1312
WIRE -432 1312 -496 1312
WIRE -384 1312 -384 1296
WIRE -384 1312 -432 1312
WIRE -352 1312 -352 1296
WIRE -304 1312 -304 1248
WIRE -304 1312 -352 1312
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WIRE -672 1360 -736 1360
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WIRE -560 1424 -640 1424
WIRE -432 1424 -432 1312
WIRE -432 1424 -496 1424
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WIRE -880 1472 -880 1360
WIRE -880 1472 -912 1472
WIRE -816 1472 -880 1472
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WIRE -672 1472 -736 1472
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WIRE -384 1472 -672 1472
WIRE -352 1472 -352 1456
WIRE -304 1472 -304 1312
WIRE -304 1472 -352 1472
WIRE -912 1536 -912 1472
WIRE -640 1536 -912 1536
WIRE -576 1536 -640 1536
WIRE -432 1536 -496 1536
WIRE -384 1536 -384 1520
WIRE -384 1536 -432 1536
WIRE -352 1536 -352 1520
WIRE -304 1536 -304 1472
WIRE -304 1536 -352 1536
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WIRE -672 1584 -736 1584
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WIRE -560 1648 -640 1648
WIRE -432 1648 -432 1536
WIRE -432 1648 -496 1648
WIRE -912 1696 -912 1536
WIRE -880 1696 -880 1584
WIRE -880 1696 -912 1696
WIRE -816 1696 -880 1696
WIRE -672 1696 -672 1584
WIRE -672 1696 -736 1696
WIRE -384 1696 -384 1680
WIRE -384 1696 -672 1696
WIRE -352 1696 -352 1680
WIRE -304 1696 -304 1536
WIRE -304 1696 -352 1696
WIRE -912 1760 -912 1696
WIRE -640 1760 -912 1760
WIRE -576 1760 -640 1760
WIRE -432 1760 -496 1760
WIRE -384 1760 -384 1744
WIRE -384 1760 -432 1760
WIRE -352 1760 -352 1744
WIRE -304 1760 -304 1696
WIRE -304 1760 -352 1760
WIRE -800 1808 -880 1808
WIRE -672 1808 -736 1808
WIRE -640 1872 -640 1760
WIRE -560 1872 -640 1872
WIRE -432 1872 -432 1760
WIRE -432 1872 -496 1872
WIRE -912 1920 -912 1760
WIRE -880 1920 -880 1808
WIRE -880 1920 -912 1920
WIRE -816 1920 -880 1920
WIRE -672 1920 -672 1808
WIRE -672 1920 -736 1920
WIRE -384 1920 -384 1904
WIRE -384 1920 -672 1920
WIRE -352 1920 -352 1904
WIRE -304 1920 -304 1760
WIRE -304 1920 -352 1920
WIRE -912 1984 -912 1920
WIRE -640 1984 -912 1984
WIRE -576 1984 -640 1984
WIRE -432 1984 -496 1984
WIRE -384 1984 -384 1968
WIRE -384 1984 -432 1984
WIRE -352 1984 -352 1968
WIRE -304 1984 -304 1920
WIRE -304 1984 -352 1984
WIRE -640 2096 -640 1984
WIRE -560 2096 -640 2096
WIRE -432 2096 -432 1984
WIRE -432 2096 -496 2096
FLAG 256 688 0
FLAG -272 416 0
FLAG -368 416 0
FLAG 336 1040 0
FLAG 400 992 0
FLAG 464 992 0
FLAG 352 688 0
FLAG 256 576 +V
FLAG 352 576 -V
FLAG 992 960 +V
FLAG 992 1056 -V
FLAG 944 1024 0
FLAG -1200 240 0
FLAG 1280 1008 OUT
FLAG -656 432 0
FLAG -448 368 0
FLAG -160 416 0
FLAG -688 832 0
FLAG -400 976 0
FLAG -352 1136 0
FLAG -48 640 0
FLAG -16 1200 -V
FLAG -16 512 +V
FLAG -768 864 0
FLAG -816 544 0
FLAG -912 240 IN
FLAG 224 1040 0
FLAG 1088 416 0
FLAG 832 480 0
FLAG 864 1088 0
FLAG 304 400 0
FLAG 144 400 0
FLAG -16 400 0
SYMBOL voltage 256 576 R0
SYMATTR InstName V1
SYMATTR Value 15
SYMBOL ind2 -432 256 R0
WINDOW 0 1 37 Right 2
WINDOW 3 -2 74 Right 2
SYMATTR InstName T3a
SYMATTR Value 25ľ
SYMATTR Type ind
SYMBOL ind2 -432 368 R0
WINDOW 0 -2 42 Right 2
WINDOW 3 -7 76 Right 2
SYMATTR InstName T3b
SYMATTR Value 25ľ
SYMATTR Type ind
SYMBOL ind2 -352 304 M0
WINDOW 0 2 39 Right 2
WINDOW 3 2 74 Right 2
SYMATTR InstName T3c
SYMATTR Value 25ľ
SYMATTR Type ind
SYMBOL res -288 304 R0
SYMATTR InstName R1
SYMATTR Value 500
SYMBOL res -32 288 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 25K
SYMBOL ind2 400 976 R180
WINDOW 0 1 71 Right 2
WINDOW 3 2 37 Right 2
SYMATTR InstName T1b
SYMATTR Value 100ľ
SYMATTR Type ind
SYMBOL ind2 400 1120 R180
WINDOW 0 1 70 Right 2
WINDOW 3 2 37 Right 2
SYMATTR InstName T1c
SYMATTR Value 100ľ
SYMATTR Type ind
SYMBOL ind2 320 1040 M180
WINDOW 0 0 72 Right 2
WINDOW 3 2 38 Right 2
SYMATTR InstName T1a
SYMATTR Value 100ľ
SYMATTR Type ind
SYMBOL njf 672 880 R0
WINDOW 3 56 54 Left 2
WINDOW 0 56 24 Left 2
SYMATTR Value 2N4416
SYMATTR InstName Q1
SYMBOL njf 672 1104 M180
WINDOW 0 56 73 Left 2
WINDOW 3 58 23 Left 2
SYMATTR InstName Q2
SYMATTR Value 2N4416
SYMBOL njf 528 880 M0
WINDOW 0 39 2 Right 2
WINDOW 3 36 101 Right 2
SYMATTR InstName Q3
SYMATTR Value 2N4416
SYMBOL njf 528 1104 R180
WINDOW 0 39 90 Right 2
WINDOW 3 35 7 Right 2
SYMATTR InstName Q4
SYMATTR Value 2N4416
SYMBOL voltage 352 576 R0
SYMATTR InstName V2
SYMATTR Value -15
SYMBOL current -1152 240 M90
WINDOW 0 -32 40 VBottom 2
WINDOW 3 32 40 VTop 2
WINDOW 123 74 40 VTop 2
WINDOW 39 53 40 VTop 2
SYMATTR InstName I1
SYMATTR Value PULSE(0 1000p 1m 1u 1u 5m 10m)
SYMBOL res -720 1232 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 100G
SYMBOL cap -736 1120 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value .015p
SYMBOL ind2 -816 352 M90
WINDOW 0 4 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName T2a
SYMATTR Value 50ľ
SYMATTR Type ind
SYMBOL ind2 -704 352 M90
WINDOW 0 4 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName T2b
SYMATTR Value 50ľ
SYMATTR Type ind
SYMBOL ind2 -656 448 M270
WINDOW 0 32 56 VTop 2
WINDOW 3 10 55 VBottom 2
SYMATTR InstName T2c
SYMATTR Value 50ľ
SYMATTR Type ind
SYMBOL cap -176 400 M180
WINDOW 0 24 56 Left 2
WINDOW 3 24 8 Left 2
SYMATTR InstName C2
SYMATTR Value 4n
SYMBOL cap 1008 800 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
WINDOW 123 60 32 VTop 2
SYMATTR InstName C3
SYMATTR Value 1000p
SYMATTR Value2 IC=0
SYMBOL Opamps\\LT1001 992 944 R0
WINDOW 3 -40 153 Left 2
SYMATTR InstName U1
SYMBOL njf -624 816 M270
WINDOW 0 51 48 VTop 2
WINDOW 3 -3 44 VLeft 2
SYMATTR InstName Q5
SYMATTR Value 2N4416
SYMBOL npn -576 720 R0
SYMATTR InstName Q6
SYMATTR Value 2N3904
SYMBOL res -528 1008 R0
SYMATTR InstName R4
SYMATTR Value 4.99K
SYMBOL cap -432 848 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C4
SYMATTR Value .01ľ
SYMBOL res -416 864 R0
SYMATTR InstName R5
SYMATTR Value 1K
SYMBOL npn -336 816 R0
SYMATTR InstName Q7
SYMATTR Value 2N3904
SYMBOL res -288 1072 R0
SYMATTR InstName R6
SYMATTR Value 4.75K
SYMBOL cap -368 1056 R0
SYMATTR InstName C5
SYMATTR Value .01ľ
SYMBOL res -288 544 R0
SYMATTR InstName R7
SYMATTR Value 2.5K
SYMBOL pnp -224 752 M180
WINDOW 0 59 68 Left 2
WINDOW 3 61 34 Left 2
SYMATTR InstName Q8
SYMATTR Value 2N3906
SYMBOL res -176 512 R0
SYMATTR InstName R8
SYMATTR Value 1.98K
SYMBOL cap -128 624 M90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C6
SYMATTR Value .01ľ
SYMBOL res -176 1088 R0
SYMATTR InstName R9
SYMATTR Value 4.22K
SYMBOL npn -80 720 R0
SYMATTR InstName Q9
SYMATTR Value 2N3904
SYMBOL cap -784 848 M180
WINDOW 0 24 56 Left 2
WINDOW 3 24 8 Left 2
SYMATTR InstName C7
SYMATTR Value 2n
SYMBOL res -624 576 R0
SYMATTR InstName R10
SYMATTR Value 1.2K
SYMBOL pnp -80 1136 M180
WINDOW 0 59 68 Left 2
WINDOW 3 61 34 Left 2
SYMATTR InstName Q10
SYMATTR Value 2N3906
SYMBOL diode -176 832 R0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode -176 960 R0
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL res -32 816 R0
SYMATTR InstName R11
SYMATTR Value 49.9
SYMBOL res -32 928 R0
SYMATTR InstName R12
SYMATTR Value 49.9
SYMBOL cap 192 912 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
WINDOW 39 60 32 VTop 2
SYMATTR InstName C8
SYMATTR Value .1ľ
SYMBOL res -720 1680 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R13
SYMATTR Value 10Meg
SYMBOL cap -736 1568 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C9
SYMATTR Value 2.5p
SYMBOL res -480 1744 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R14
SYMATTR Value 1Meg
SYMBOL res -720 1904 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R15
SYMATTR Value 100K
SYMBOL cap -496 1856 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C10
SYMATTR Value 75p
SYMBOL cap -736 1792 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C11
SYMATTR Value 100p
SYMBOL cap 944 704 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
WINDOW 123 60 32 VTop 2
SYMATTR InstName C12
SYMATTR Value .05ľ
SYMATTR Value2 IC=0
SYMBOL cap 1008 608 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
WINDOW 123 60 32 VTop 2
SYMATTR InstName C13
SYMATTR Value .1ľ
SYMATTR Value2 IC=0
SYMBOL njf -800 384 R90
WINDOW 0 34 48 VCenter 2
WINDOW 3 61 46 VCenter 2
SYMATTR InstName J3
SYMATTR Value 2N5432
SYMBOL njf -800 272 R90
WINDOW 0 34 48 VCenter 2
WINDOW 3 61 46 VCenter 2
SYMATTR InstName J1
SYMATTR Value 2N5432
SYMBOL njf -512 464 M270
WINDOW 0 34 48 VCenter 2
WINDOW 3 61 46 VCenter 2
SYMATTR InstName J4
SYMATTR Value 2N5432
SYMBOL njf -512 352 M270
WINDOW 0 34 48 VCenter 2
WINDOW 3 61 46 VCenter 2
SYMATTR InstName J2
SYMATTR Value 2N5432
SYMBOL res -480 1296 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R16
SYMATTR Value 10G
SYMBOL cap -496 1408 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C14
SYMATTR Value .04p
SYMBOL cap 944 880 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
WINDOW 123 60 32 VTop 2
SYMATTR InstName C15
SYMATTR Value 25p
SYMATTR Value2 IC=0
SYMBOL cap -896 528 M90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C16
SYMATTR Value 100p
SYMBOL res -720 1456 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R17
SYMATTR Value 1G
SYMBOL cap -736 1344 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C17
SYMATTR Value .2p
SYMBOL res -480 1520 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R18
SYMATTR Value 100Meg
SYMBOL cap -496 1632 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C18
SYMATTR Value .4p
SYMBOL res -480 1968 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R19
SYMATTR Value 10K
SYMBOL cap -496 2080 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C19
SYMATTR Value 50p
SYMBOL cap 208 1008 M180
WINDOW 0 24 56 Left 2
WINDOW 3 24 8 Left 2
SYMATTR InstName C20
SYMATTR Value 1n
SYMBOL Digital\\dflop 752 320 M0
WINDOW 0 -10 75 Center 2
WINDOW 3 -97 197 Left 2
WINDOW 123 -56 165 Left 2
SYMATTR InstName A1
SYMATTR Value Vhigh=0 Vlow=-5
SYMATTR Value2 Trise=10n
SYMBOL voltage 976 416 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 -32 56 VBottom 2
SYMATTR InstName V3
SYMATTR Value pulse(-5 0 0 10n 10n .5u 1u)
SYMBOL cap 848 1008 R0
SYMATTR InstName C21
SYMATTR Value .01ľ
SYMBOL res 864 976 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R20
SYMATTR Value 100
SYMBOL res 144 912 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R21
SYMATTR Value 500
SYMBOL cap 288 320 R0
SYMATTR InstName C22
SYMATTR Value 1n
SYMBOL res 448 288 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R22
SYMATTR Value 100
SYMBOL cap 128 320 R0
SYMATTR InstName C23
SYMATTR Value 500p
SYMBOL res 288 288 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R23
SYMATTR Value 200
SYMBOL cap -32 320 R0
SYMATTR InstName C24
SYMATTR Value 250p
SYMBOL res 128 288 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R24
SYMATTR Value 400
TEXT 792 1392 Left 2 !.tran 15m
TEXT -384 256 Bottom 2 !K3 T3a T3b T3c 1.
TEXT 392 864 Bottom 2 !K1 T1a T1b T1c 1.
TEXT -704 232 Bottom 2 !K2 T2a T2b T2c 1.
TEXT -24 216 Bottom 2 ;Old Fashioned Electrometer Using Parametric up Conversion\nThese days you should just use a AD549
TEXT -536 1368 Center 2 ;ą1nA full scale
TEXT -768 1640 Center 2 ;ą1ľA full scale
TEXT -776 1864 Center 2 ;ą100ľA full scale
TEXT 1088 816 Left 2 ;Add for ą1ľA full scale
TEXT -536 1816 Center 2 ;ą10ľA full scale
TEXT 1088 624 Left 2 ;Add for ą100ľA, ą1mA full scale
TEXT -776 1192 Center 2 ;ą100pA full scale
TEXT 1088 896 Left 2 ;ą100pA, ą1nA, ą10nA, ą100nA full scale
TEXT -768 1416 Center 2 ;ą10nA full scale
TEXT -536 1592 Center 2 ;ą100nA full scale
TEXT 1088 720 Left 2 ;Add for ą10ľA full scale
TEXT -536 2040 Center 2 ;ą1mA full scale
TEXT -216 1544 Left 2 ;A 1% mismatch in J1, J2, J3, J4 capacitiances give a 6mV input offset and a 425mV output offset(4.25pA readout error) at ą100pA full scale range.\nQ1, Q2, Q3, Q4 require a low drive impedance lest the gain of the loop inverts at high input currents.
TEXT 1184 1008 Bottom 2 ;ą10V full scale
TEXT 976 1120 Top 2 ;Trim to reduce\nerror to a\nfraction of 1pA