Version 4 SHEET 1 880 680 WIRE 32 -192 16 -192 WIRE 160 -176 160 -208 WIRE 160 -176 80 -176 WIRE 160 -160 160 -176 WIRE 320 -160 256 -160 WIRE -48 -112 -48 -192 WIRE -48 -112 -64 -112 WIRE 32 -112 32 -192 WIRE 96 -112 32 -112 WIRE 320 -112 320 -160 WIRE 368 -112 320 -112 WIRE 368 -96 368 -112 WIRE 240 -64 160 -64 WIRE 256 -64 240 -64 WIRE 240 -16 240 -64 WIRE 304 -16 240 -16 WIRE 608 -16 576 -16 WIRE -64 16 -64 -112 WIRE -48 16 -64 16 WIRE 304 16 304 -16 WIRE 32 32 32 -112 WIRE 32 32 16 32 WIRE 288 32 208 32 WIRE -48 48 -64 48 WIRE -64 64 -64 48 WIRE 80 80 80 -176 WIRE 144 80 144 32 WIRE 144 80 80 80 WIRE 208 80 144 80 WIRE 288 96 288 32 WIRE 288 96 272 96 WIRE 304 96 288 96 WIRE 464 96 304 96 WIRE 576 96 576 -16 WIRE 576 96 544 96 WIRE 592 96 576 96 WIRE 208 112 192 112 WIRE 688 112 688 -16 WIRE 688 112 656 112 WIRE 704 112 688 112 WIRE 192 128 192 112 WIRE 592 128 560 128 WIRE 560 144 560 128 WIRE -144 176 -144 16 FLAG -16 0 +12V FLAG -16 64 -12V FLAG -64 64 0 FLAG 240 64 +12V FLAG 240 128 -12V FLAG -256 144 0 FLAG -256 64 +12V FLAG -368 64 -12V FLAG -368 144 0 FLAG -144 256 0 FLAG 368 -96 0 FLAG 160 -288 +12V FLAG 192 128 0 FLAG 560 144 0 FLAG 624 144 -12V FLAG 624 80 +12V SYMBOL TL072 -16 -32 R0 SYMATTR InstName U1 SYMBOL TL072 240 32 R0 SYMATTR InstName U2 SYMBOL voltage -256 48 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 12 SYMBOL voltage -368 48 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value -12 SYMBOL voltage -144 160 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value PULSE(0 10 0 .25 .25 0 .5) SYMBOL npn 96 -160 R0 SYMATTR InstName Q1 SYMATTR Value BC847C SYMBOL npn 320 -160 M0 SYMATTR InstName Q2 SYMATTR Value BC847C SYMBOL res 144 -304 R0 SYMATTR InstName R1 SYMATTR Value 10Meg SYMBOL res 48 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 1k SYMBOL res 288 0 R0 SYMATTR InstName R3 SYMATTR Value 1k5 SYMBOL cap 208 16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 100p SYMBOL cap 16 -208 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 100p SYMBOL res -48 0 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 100k SYMBOL TL072 624 48 R0 SYMATTR InstName U3 SYMBOL res 704 -32 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL res 560 80 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 10k TEXT -402 280 Left 2 !.tran 1s