Version 4
SHEET 1 880 680
WIRE 272 -144 48 -144
WIRE 416 -144 368 -144
WIRE 480 -144 416 -144
WIRE 608 -144 480 -144
WIRE 416 -128 416 -144
WIRE 48 -48 48 -144
WIRE 160 -48 48 -48
WIRE 208 -48 160 -48
WIRE 416 -48 416 -64
WIRE 416 -48 288 -48
WIRE 416 -32 416 -48
WIRE 480 32 480 -144
WIRE 448 64 80 64
WIRE 320 96 320 -80
WIRE 336 96 320 96
WIRE 416 96 416 48
WIRE 416 96 400 96
WIRE 160 144 160 -48
WIRE 320 144 320 96
WIRE 80 192 80 64
WIRE 96 192 80 192
WIRE 416 192 416 96
WIRE 416 192 384 192
WIRE 480 192 480 96
WIRE 48 256 48 -48
WIRE 160 256 160 240
WIRE 240 256 160 256
WIRE 320 256 320 240
WIRE 320 256 240 256
WIRE 416 256 416 192
WIRE 416 256 352 256
WIRE 608 256 608 -144
WIRE 240 272 240 256
WIRE 352 272 352 256
WIRE 416 272 416 256
WIRE 48 368 48 336
WIRE 240 368 240 352
WIRE 240 368 48 368
WIRE 352 368 352 336
WIRE 352 368 240 368
WIRE 416 368 416 336
WIRE 416 368 352 368
WIRE 480 368 480 272
WIRE 480 368 416 368
WIRE 608 368 608 336
WIRE 608 368 480 368
WIRE 240 384 240 368
FLAG 240 384 0
SYMBOL npn2 96 144 R0
WINDOW 0 20 49 Left 0
WINDOW 3 82 2 VRight 0
SYMATTR InstName Q1
SYMATTR Value BC547B
SYMBOL pnp2 368 -80 M270
WINDOW 0 38 64 VLeft 0
WINDOW 3 65 88 VLeft 0
SYMATTR InstName Q3
SYMATTR Value BD440
SYMBOL npn2 384 144 M0
WINDOW 0 20 49 Left 0
WINDOW 3 82 2 VRight 0
SYMATTR InstName Q2
SYMATTR Value BC547B
SYMBOL res 224 256 R0
SYMATTR InstName R1
SYMATTR Value 100
SYMBOL cap 400 80 R90
WINDOW 0 50 4 VBottom 0
WINDOW 3 56 14 VTop 0
SYMATTR InstName C1
SYMATTR Value 100p
SYMBOL zener 432 336 R180
WINDOW 0 -24 -12 VRight 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName Dz4v7
SYMATTR Value 1N752
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 400 -48 R0
WINDOW 0 -21 26 Left 0
WINDOW 3 -20 62 Left 0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res 304 -64 R90
WINDOW 0 16 107 VBottom 0
WINDOW 3 -12 24 VTop 0
SYMATTR InstName R3
SYMATTR Value 22k
SYMBOL diode 400 -128 R0
WINDOW 0 -35 31 Left 0
WINDOW 3 -59 65 Left 0
SYMATTR InstName D1
SYMATTR Value 1N34A
SYMBOL res 464 176 R0
WINDOW 0 -28 30 Left 0
WINDOW 3 -29 64 Left 0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL res 592 240 R0
WINDOW 0 -28 30 Left 0
WINDOW 3 -25 60 Left 0
SYMATTR InstName RL
SYMATTR Value 6
SYMBOL polcap 336 272 R0
WINDOW 3 24 64 Left 0
SYMATTR Value 2.2u
SYMATTR InstName C2
SYMATTR Description Capacitor
SYMATTR Type cap
SYMATTR SpiceLine V=50 Irms=54m Rser=3 Lser=0 mfg="Nichicon" pn="UPL1H2R2MAH" type="Al electrolytic"
SYMBOL voltage 48 240 R0
WINDOW 0 -20 59 Left 0
WINDOW 3 7 8 Left 0
SYMATTR InstName Vcc
SYMATTR Value 20v
SYMBOL Robertugo\\Pote 464 0 R0
WINDOW 0 41 40 Left 0
WINDOW 123 76 111 Center 0
SYMATTR InstName U1
SYMATTR Value Rt=5k
SYMATTR Value2 Set={cur}
TEXT 70 352 Left 0 !.tran 1m
TEXT 280 384 Left 0 !.step param cur 0 1 .1