Version 4 SHEET 1 2236 680 WIRE -304 16 -336 16 WIRE 400 16 -224 16 WIRE 128 32 -32 32 WIRE 304 32 128 32 WIRE -32 48 -32 32 WIRE 128 48 128 32 WIRE 304 48 304 32 WIRE -32 144 -32 128 WIRE 304 144 304 128 WIRE -336 192 -336 16 WIRE -320 192 -336 192 WIRE -192 192 -240 192 WIRE -96 192 -192 192 WIRE 400 192 400 16 WIRE 400 192 368 192 WIRE 400 208 400 192 WIRE 128 240 -32 240 WIRE 304 240 128 240 WIRE 128 256 128 240 WIRE -192 272 -192 192 WIRE -336 304 -336 192 WIRE 48 304 -32 304 WIRE 64 304 48 304 WIRE 400 320 400 288 WIRE 48 368 48 304 WIRE -192 416 -192 352 WIRE 128 432 48 432 FLAG 128 128 0 FLAG 128 512 0 FLAG -32 384 0 FLAG -336 384 0 FLAG -192 496 0 FLAG 400 320 0 SYMBOL voltage 128 32 R0 WINDOW 0 -63 56 Left 0 WINDOW 3 38 55 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 24 132 Left 0 SYMATTR InstName V1 SYMATTR Value 9 SYMBOL voltage 128 528 R180 WINDOW 0 38 57 Left 0 WINDOW 3 -51 56 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 24 -12 Left 0 SYMATTR InstName V2 SYMATTR Value 9 SYMBOL res 112 336 R0 WINDOW 0 36 57 Left 0 WINDOW 3 76 57 Left 0 SYMATTR InstName R1 SYMATTR Value 2k SYMBOL zener 64 432 R180 WINDOW 0 -21 64 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value 1N750 SYMBOL npn 64 256 R0 SYMATTR InstName Q1 SYMBOL npn -96 144 R0 SYMATTR InstName Q2 SYMBOL npn 368 144 M0 SYMATTR InstName Q3 SYMBOL res -48 32 R0 SYMATTR InstName R2 SYMATTR Value 4.7k SYMBOL res 288 32 R0 SYMATTR InstName R3 SYMATTR Value 4.7k SYMBOL res -48 288 R0 WINDOW 0 35 59 Left 0 WINDOW 3 -43 59 Left 0 SYMATTR InstName R4 SYMATTR Value 390 SYMBOL voltage -336 288 R0 WINDOW 0 38 55 Left 0 WINDOW 3 -66 132 Left 0 WINDOW 123 -44 165 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value SINE(0 2 60) SYMBOL res -224 176 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL res -176 368 R180 WINDOW 0 36 76 Left 0 WINDOW 3 36 40 Left 0 SYMATTR InstName R6 SYMATTR Value 10k SYMBOL voltage -192 400 R0 WINDOW 0 37 58 Left 0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value SINE(0 .3 2k) SYMBOL res -208 0 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res 384 192 R0 SYMATTR InstName R5 SYMATTR Value 10k TEXT 304 472 Left 0 !.tran 0 20e-3 1e-6 1e-6 TEXT -360 600 Left 0 ;V3 is the common-mode signal source and V4 is the differential signal source. TEXT -160 -112 Left 0 ;Reference circuit: Schuler, 7th edition, page 247 TEXT 80 168 Left 0 ;DC source TEXT 64 544 Left 0 ;DC source TEXT 216 440 Left 0 ;SPICE directive for transient analysis TEXT -160 -80 Left 0 ;Run the simulation and then probe for waveforms. TEXT -160 -48 Left 0 ;Probe both the base and the collector of Q2. TEXT -160 -16 Left 0 ;The 60 Hz common-mode signal is nicely rejected! RECTANGLE Normal 672 496 192 416