Version 4
SHEET 1 1144 1448
WIRE -3552 16 -3728 16
WIRE -3344 16 -3552 16
WIRE -2928 16 -3344 16
WIRE -2720 16 -2928 16
WIRE -2544 16 -2720 16
WIRE -3344 64 -3344 16
WIRE -2928 64 -2928 16
WIRE -3552 96 -3552 16
WIRE -2720 112 -2720 16
WIRE -2544 112 -2544 16
WIRE -3344 192 -3344 144
WIRE -3152 192 -3344 192
WIRE -2928 192 -2928 144
WIRE -2928 192 -3088 192
WIRE -2544 224 -2544 192
WIRE -3552 240 -3552 176
WIRE -3408 240 -3552 240
WIRE -2720 240 -2720 192
WIRE -2720 240 -2864 240
WIRE -3552 352 -3552 240
WIRE -3552 352 -3792 352
WIRE -2720 352 -2720 240
WIRE -2544 352 -2720 352
WIRE -3552 400 -3552 352
WIRE -2720 400 -2720 352
WIRE -3344 448 -3344 288
WIRE -3344 448 -3488 448
WIRE -2928 448 -2928 288
WIRE -2784 448 -2928 448
WIRE -3792 560 -3792 432
WIRE -2544 560 -2544 432
WIRE -3552 752 -3552 496
WIRE -2720 768 -2720 496
FLAG -2544 224 0
FLAG -2720 768 0
FLAG -3552 752 0
FLAG -2544 560 0
FLAG -3792 560 0
SYMBOL voltage -2544 96 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value 3
SYMBOL npn -2784 400 R0
SYMATTR InstName Q2
SYMATTR Value 2N3904
SYMBOL pnp -2864 288 R180
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL res -2736 96 R0
SYMATTR InstName R1
SYMATTR Value 5MEG
SYMBOL res -2944 48 R0
SYMATTR InstName R3
SYMATTR Value 5.5MEG
SYMBOL res -2560 336 R0
SYMATTR InstName R2
SYMATTR Value 5MEG
SYMBOL pnp -3408 288 M180
SYMATTR InstName Q3
SYMATTR Value 2N3906
SYMBOL npn -3488 400 M0
SYMATTR InstName Q4
SYMATTR Value 2N3904
SYMBOL res -3360 48 R0
SYMATTR InstName R4
SYMATTR Value 5MEG
SYMBOL res -3568 80 R0
SYMATTR InstName R5
SYMATTR Value 5MEG
SYMBOL res -3808 336 R0
SYMATTR InstName R6
SYMATTR Value 5MEG
SYMBOL cap -3088 176 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 10nF
TEXT -3064 -216 Left 2 !.tran 0 1500m 0 50u uic
TEXT -3008 600 Left 2 ;David Pilling 2015