Version 4
SHEET 1 880 680
WIRE 32 96 -64 96
WIRE 144 96 32 96
WIRE 272 96 240 96
WIRE 304 96 272 96
WIRE 416 96 384 96
WIRE 464 96 416 96
WIRE 512 96 464 96
WIRE 272 176 272 96
WIRE -64 208 -64 96
WIRE 512 208 512 96
WIRE 32 240 32 96
WIRE 64 240 32 240
WIRE 192 240 192 160
WIRE 192 240 144 240
WIRE 224 240 192 240
WIRE 416 240 416 96
WIRE 416 240 320 240
WIRE 192 304 192 240
WIRE -64 400 -64 288
WIRE 192 400 192 368
WIRE 512 400 512 288
FLAG 192 400 0
FLAG -64 400 0
FLAG 464 96 V_out
FLAG 512 400 0
SYMBOL npn 144 160 R270
SYMATTR InstName Q1
SYMATTR Value BC546B
SYMBOL npn 224 176 M90
SYMATTR InstName Q2
SYMATTR Value BC546B
SYMBOL res 288 112 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value 8
SYMBOL zener 208 368 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value BZX84C6V2L
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 48 224 M90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 560
SYMBOL voltage -64 192 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 9
SYMBOL res 496 192 R0
SYMATTR InstName R3
SYMATTR Value {R_Load}
TEXT -72 472 Left 2 !.param R_load 1k\n.step dec param R_Load 10m 10k 100
TEXT -64 448 Left 2 !.op