Version 4
SHEET 1 880 680
WIRE 176 -64 -80 -64
WIRE 432 -64 176 -64
WIRE 432 -16 432 -64
WIRE -80 16 -80 -64
WIRE 432 80 432 64
WIRE 544 80 432 80
WIRE 608 80 544 80
WIRE 176 144 176 -64
WIRE 432 144 432 80
WIRE -80 192 -80 96
WIRE -80 192 -160 192
WIRE 96 192 64 192
WIRE 112 192 96 192
WIRE 528 192 496 192
WIRE 592 192 528 192
WIRE -160 224 -160 192
WIRE 64 224 64 192
WIRE -80 272 -80 192
WIRE 176 272 176 240
WIRE 288 272 176 272
WIRE 336 272 288 272
WIRE 432 272 432 240
WIRE 432 272 336 272
WIRE 288 320 288 272
WIRE 592 320 592 192
WIRE 64 352 64 304
WIRE -80 432 -80 352
WIRE 288 432 288 400
WIRE 288 432 -80 432
FLAG -160 224 0
FLAG 544 80 out
FLAG 64 352 0
FLAG 592 320 0
FLAG 528 192 V-
FLAG 96 192 V+
FLAG 336 272 Vtail
SYMBOL npn 112 144 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL npn 496 144 M0
SYMATTR InstName Q2
SYMATTR Value 2N3904
SYMBOL res 416 -32 R0
SYMATTR InstName Rload
SYMATTR Value 2k
SYMBOL res 272 304 R0
SYMATTR InstName Rtail
SYMATTR Value 1k
SYMBOL voltage -80 0 R0
SYMATTR InstName V1
SYMATTR Value 6V
SYMBOL voltage -80 256 R0
SYMATTR InstName V2
SYMATTR Value 6V
SYMBOL voltage 64 208 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName Vin
SYMATTR Value ""
TEXT -184 440 Left 2 !.dc Vin -6 6 0.001