Version 4
SHEET 1 944 728
WIRE 0 -112 -144 -112
WIRE 112 -112 0 -112
WIRE 352 -112 112 -112
WIRE 464 -112 352 -112
WIRE 592 -112 464 -112
WIRE 768 -112 688 -112
WIRE 864 -112 768 -112
WIRE 464 -64 464 -112
WIRE 864 -48 864 -112
WIRE 352 -16 352 -32
WIRE 400 -16 352 -16
WIRE -144 16 -144 -112
WIRE 352 16 352 -16
WIRE 768 48 768 -112
WIRE 464 64 464 32
WIRE 464 64 416 64
WIRE 464 80 464 64
WIRE 864 96 864 32
WIRE -144 112 -144 96
WIRE 0 176 0 -112
WIRE 464 176 464 160
WIRE 352 192 352 112
WIRE 352 192 288 192
WIRE 672 192 672 -64
WIRE 672 192 352 192
WIRE -144 208 -144 192
WIRE 112 272 112 -112
WIRE 352 272 352 192
WIRE 288 288 288 272
WIRE 0 320 0 256
WIRE 48 320 0 320
WIRE 768 320 768 128
WIRE 768 320 416 320
WIRE 240 368 112 368
WIRE 352 368 240 368
WIRE 0 384 0 320
WIRE 240 416 240 368
WIRE 0 496 0 464
WIRE 240 528 240 496
WIRE 0 592 0 560
WIRE 0 688 0 656
FLAG -144 208 0
FLAG 464 176 0
FLAG 240 528 0
FLAG 288 288 0
FLAG 0 688 0
FLAG 864 96 0
SYMBOL voltage -144 96 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 230
SYMBOL res -160 0 R0
SYMATTR InstName R5
SYMATTR Value 352.6
SYMBOL pnp 416 112 R180
SYMATTR InstName Q1
SYMBOL pnp 400 32 M180
SYMATTR InstName Q2
SYMBOL res 336 -128 R0
SYMATTR InstName R1
SYMATTR Value 1.7k
SYMBOL res 448 64 R0
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL npn 48 272 R0
SYMATTR InstName Q3
SYMBOL npn 416 272 M0
WINDOW 3 56 60 Left 0
SYMATTR InstName Q4
SYMBOL res 224 400 R0
SYMATTR InstName R3
SYMATTR Value 270k
SYMBOL res 272 176 R0
SYMATTR InstName R4
SYMATTR Value 1Meg
SYMBOL zener 16 560 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D1
SYMATTR Value ZENER51V
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL zener 16 656 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D2
SYMATTR Value ZENER51V
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL nmos 592 -64 R270
SYMATTR InstName M1
SYMATTR Value STP8NM60
SYMBOL res 848 -64 R0
SYMATTR InstName R7
SYMATTR Value 100k
SYMBOL res 752 32 R0
SYMATTR InstName R8
SYMATTR Value 220k
SYMBOL res -16 160 R0
SYMATTR InstName R6
SYMATTR Value {1+RP*pos}
SYMBOL res -16 368 R0
SYMATTR InstName R10
SYMATTR Value {1+RP*(1-pos)}
TEXT 336 -296 Left 0 !.step param pos 1 0 0.1
TEXT 336 -256 Left 0 !.param RP 100k
TEXT -208 712 Left 0 !.op
TEXT -640 -192 Left 0 !.model ZENER51V D(Is=.6n Rs=.5 Cjo=110p nbv=6 bv=51 Ibv=1m Vpk=51 type=zener)