Version 4
SHEET 1 1060 840
WIRE -16 64 -96 64
WIRE 64 64 -16 64
WIRE 160 64 128 64
WIRE 240 64 160 64
WIRE 784 64 240 64
WIRE 928 64 784 64
WIRE 160 80 160 64
WIRE 784 96 784 64
WIRE -96 128 -96 64
WIRE 240 128 240 64
WIRE -608 144 -608 112
WIRE -496 144 -496 112
WIRE -400 144 -400 112
WIRE 592 144 592 96
WIRE 672 144 592 144
WIRE 752 144 736 144
WIRE 928 144 928 64
WIRE 160 160 160 144
WIRE 160 160 32 160
WIRE 592 160 592 144
WIRE -16 176 -16 64
WIRE 160 176 -16 176
WIRE 752 208 752 144
WIRE 752 208 656 208
WIRE 784 208 784 176
WIRE 784 208 752 208
WIRE -608 256 -608 224
WIRE -496 256 -496 224
WIRE -400 256 -400 224
WIRE -96 256 -96 208
WIRE 32 256 32 160
WIRE 32 256 -96 256
WIRE 64 256 32 256
WIRE 160 256 160 240
WIRE 160 256 128 256
WIRE 240 256 240 192
WIRE 240 256 160 256
WIRE 592 288 592 256
WIRE 448 304 448 256
WIRE 448 304 288 304
WIRE 928 320 928 224
WIRE 448 336 448 304
WIRE 288 352 288 304
WIRE 592 384 592 368
WIRE 592 384 512 384
WIRE 592 416 592 384
WIRE 288 464 288 432
WIRE 448 464 448 432
WIRE 448 464 288 464
WIRE 240 560 240 256
WIRE 448 560 448 544
WIRE 448 560 240 560
WIRE 592 560 592 480
WIRE 592 560 448 560
WIRE 592 592 592 560
WIRE 448 656 448 624
WIRE 592 688 592 656
WIRE 448 736 448 720
FLAG -608 256 0
FLAG -496 256 0
FLAG -400 256 0
FLAG -608 112 15V
FLAG -496 112 -30V
FLAG -400 112 -38V
FLAG 448 736 -38V
FLAG 784 288 -30V
FLAG 592 96 15V
FLAG 448 256 15V
FLAG 592 688 0
FLAG 928 320 0
SYMBOL voltage -96 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value SINE(0 250 60)
SYMBOL diode 64 80 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMBOL diode 128 240 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D2
SYMBOL diode 176 240 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D3
SYMBOL diode 176 144 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D4
SYMBOL cap 224 128 R0
SYMATTR InstName C1
SYMATTR Value 1m
SYMBOL res 768 80 R0
SYMATTR InstName R832
SYMATTR Value 200k
SYMBOL res 768 192 R0
SYMATTR InstName R834
SYMATTR Value 44.2k
SYMBOL diode 736 128 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName CR835a
SYMBOL pnp 656 256 R180
SYMATTR InstName Q830
SYMATTR Value 2N2907
SYMBOL res 576 272 R0
SYMATTR InstName R836
SYMATTR Value 1k
SYMBOL zener 608 480 R180
WINDOW 0 24 64 Left 2
WINDOW 3 -113 30 Left 2
SYMATTR InstName CR835
SYMATTR Value TDZ6_2B
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL npn 512 336 M0
SYMATTR InstName Q836
SYMATTR Value 2N3904
SYMBOL res 272 336 R0
SYMATTR InstName R837
SYMATTR Value 1.8k
SYMBOL res 432 448 R0
SYMATTR InstName R838
SYMATTR Value 30
SYMBOL zener 432 560 R0
SYMATTR InstName VR836
SYMATTR Value UDZV20B
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL diode 464 720 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName CR836
SYMBOL voltage -608 128 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value 15
SYMBOL voltage -496 240 R180
WINDOW 0 24 96 Left 2
WINDOW 3 24 16 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V3
SYMATTR Value 30
SYMBOL voltage -400 240 R180
WINDOW 0 24 96 Left 2
WINDOW 3 24 16 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V4
SYMATTR Value 38
SYMBOL cap 576 592 R0
SYMATTR InstName C836
SYMATTR Value 1µ
SYMBOL res 912 128 R0
SYMATTR InstName R_LOAD
SYMATTR Value {X}
TEXT -130 308 Left 2 !.tran 1
TEXT 352 -56 Left 2 !.step param X 1k 10k 1k