Version 4
SHEET 1 880 680
WIRE 64 32 -160 32
WIRE 336 32 128 32
WIRE 672 32 400 32
WIRE 128 64 128 32
WIRE 64 128 64 32
WIRE -160 160 -160 32
WIRE 128 176 128 144
WIRE 304 176 128 176
WIRE 336 176 304 176
WIRE 448 176 416 176
WIRE 560 176 528 176
WIRE 672 176 672 32
WIRE 672 176 640 176
WIRE 304 192 304 176
WIRE 128 208 128 176
WIRE -160 320 -160 240
WIRE 64 320 64 208
WIRE 64 320 -160 320
WIRE 128 320 128 288
WIRE 336 320 128 320
WIRE 672 320 672 176
WIRE 672 320 400 320
WIRE -160 336 -160 320
FLAG -160 336 0
FLAG 304 192 0
SYMBOL ind2 112 48 R0
WINDOW 39 36 108 Left 2
SYMATTR InstName L2
SYMATTR Value 0.5
SYMATTR Type ind
SYMATTR SpiceLine Rser=0.5
SYMBOL ind2 112 192 R0
WINDOW 39 36 108 Left 2
SYMATTR InstName L3
SYMATTR Value 0.5
SYMATTR Type ind
SYMATTR SpiceLine Rser=0.5
SYMBOL ind2 80 112 M0
WINDOW 39 36 108 Left 2
SYMATTR InstName L1
SYMATTR Value 10
SYMATTR Type ind
SYMATTR SpiceLine Rser=5
SYMBOL ind 656 192 M270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
WINDOW 39 -23 56 VBottom 2
SYMATTR InstName L4
SYMATTR Value 1
SYMATTR SpiceLine Rser=0.5
SYMBOL Misc\\EuropeanResistor 544 160 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 20
SYMBOL voltage 432 176 R90
WINDOW 0 -32 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL voltage -160 144 R0
WINDOW 3 11 117 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value SINE(0 325 50)
SYMBOL diode 336 48 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMBOL diode 336 336 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D2
TEXT 24 0 Left 2 !K1 L1 L2 L3 1
TEXT -160 -88 Left 2 !.tran 0 250m 0 .1m 
LINE Normal 88 320 88 32 2
LINE Normal 104 320 88 320 2
LINE Normal 104 32 104 320 2
LINE Normal 88 32 104 32 2