Version 4
SHEET 1 880 680
WIRE 144 112 -176 112
WIRE 304 128 -160 128
WIRE 400 128 304 128
WIRE 592 128 480 128
WIRE -112 160 -128 160
WIRE 144 160 144 112
WIRE 144 160 112 160
WIRE -112 224 -144 224
WIRE 144 224 112 224
WIRE 592 272 592 128
WIRE 736 272 592 272
WIRE -160 288 -160 128
WIRE -112 288 -160 288
WIRE 224 288 112 288
WIRE 304 288 224 288
WIRE 432 288 304 288
WIRE 736 288 736 272
WIRE 592 336 592 272
WIRE -176 352 -176 112
WIRE -112 352 -176 352
WIRE 128 352 112 352
WIRE -176 384 -176 352
WIRE 128 384 128 352
WIRE 128 384 -16 384
WIRE 736 384 736 368
WIRE 736 384 656 384
WIRE -144 400 -144 224
WIRE 224 400 224 288
WIRE 224 400 -144 400
WIRE 736 416 736 384
WIRE -16 432 -16 384
WIRE 224 432 224 400
WIRE -176 480 -176 464
WIRE -128 480 -128 160
WIRE -128 480 -176 480
WIRE -176 512 -176 480
WIRE -128 528 -128 480
WIRE -16 528 -16 496
WIRE -16 528 -128 528
WIRE 224 528 224 496
WIRE 224 528 -16 528
WIRE 432 528 432 288
WIRE 592 528 592 432
WIRE 592 528 432 528
WIRE 736 528 736 496
WIRE 736 528 592 528
FLAG -176 512 0
FLAG 304 128 Sqr
IOPIN 304 128 Out
FLAG 304 288 Tri
IOPIN 304 288 Out
SYMBOL Robertugo\\555_ALL 48 272 R0
SYMATTR InstName U1
SYMBOL cap 208 432 R0
SYMATTR InstName Ct
SYMATTR Value 1n
SYMBOL cap -32 432 R0
SYMATTR InstName Cbp
SYMATTR Value 10n
SYMBOL voltage -176 368 R0
WINDOW 0 -32 6 Left 0
WINDOW 3 -15 59 Left 0
SYMATTR InstName V+
SYMATTR Value 12
SYMBOL pnp2 656 432 R180
WINDOW 0 89 64 Left 0
WINDOW 3 38 36 Left 0
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL res 496 112 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName Re
SYMATTR Value 4k7
SYMBOL res 720 272 R0
SYMATTR InstName Rb
SYMATTR Value 680
SYMBOL res 720 400 R0
SYMATTR InstName RLoad
SYMATTR Value 1k8
TEXT -114 504 Left 0 !.tran 1m