Version 4
SHEET 1 1144 1448
WIRE -2720 16 -3104 16
WIRE -2544 16 -2720 16
WIRE -3104 64 -3104 16
WIRE -2720 112 -2720 16
WIRE -2544 112 -2544 16
WIRE -3104 192 -3104 144
WIRE -2928 192 -3104 192
WIRE -2544 224 -2544 192
WIRE -2720 240 -2720 192
WIRE -2720 240 -2864 240
WIRE -2928 304 -2928 288
WIRE -2720 352 -2720 240
WIRE -2624 352 -2720 352
WIRE -2544 352 -2624 352
WIRE -3104 400 -3104 192
WIRE -2720 400 -2720 352
WIRE -2928 448 -2928 384
WIRE -2896 448 -2928 448
WIRE -2784 448 -2832 448
WIRE -2624 528 -2624 352
WIRE -2544 560 -2544 432
WIRE -2928 672 -2928 448
WIRE -2624 672 -2624 592
WIRE -2624 672 -2928 672
WIRE -3104 768 -3104 464
WIRE -2720 768 -2720 496
FLAG -2544 224 0
FLAG -2720 768 0
FLAG -3104 768 0
FLAG -2544 560 0
SYMBOL voltage -2544 96 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value 5
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 100K
SYMBOL res -3120 48 R0
SYMATTR InstName R3
SYMATTR Value 1MEG
SYMBOL cap -3120 400 R0
SYMATTR InstName C1
SYMATTR Value 1000pF
SYMBOL res -2560 336 R0
SYMATTR InstName R2
SYMATTR Value 100K
SYMBOL res -2944 288 R0
SYMATTR InstName R4
SYMATTR Value 1K
SYMBOL diode -2608 592 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value 1N914
SYMBOL diode -2896 464 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D2
SYMATTR Value 1N914
TEXT -3008 40 Left 2 !.tran 0 1.5s 0 50u uic
TEXT -2992 88 Left 2 ;David Pilling 2016