Version 4
SHEET 1 1004 680
WIRE 96 80 -48 80
WIRE 192 80 96 80
WIRE 352 80 272 80
WIRE 416 80 352 80
WIRE 544 80 480 80
WIRE 608 80 544 80
WIRE 752 80 688 80
WIRE 896 80 752 80
WIRE -48 128 -48 80
WIRE 96 128 96 80
WIRE 352 128 352 80
WIRE 544 128 544 80
WIRE 752 128 752 80
WIRE 896 128 896 80
WIRE 304 144 208 144
WIRE 208 160 208 144
WIRE 304 240 304 192
WIRE 304 240 208 240
WIRE -48 256 -48 208
WIRE 96 256 96 192
WIRE 208 256 208 240
WIRE 352 256 352 208
WIRE 544 256 544 192
WIRE 752 256 752 192
WIRE 896 256 896 208
FLAG -48 256 0
FLAG 96 256 0
FLAG 752 256 0
FLAG 896 256 0
FLAG 352 256 0
FLAG 208 256 0
FLAG 896 80 OUT
FLAG 544 256 0
SYMBOL voltage -48 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL cap 80 128 R0
SYMATTR InstName C1
SYMATTR Value 10µ
SYMBOL sw 352 112 R0
WINDOW 0 18 -8 VRight 2
WINDOW 3 50 24 VRight 2
SYMATTR InstName S1
SYMATTR Value FETsw
SYMBOL ind 176 96 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName L1
SYMATTR Value 220µ
SYMBOL schottky 560 128 M0
SYMATTR InstName D1
SYMATTR Value 1N5819
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL cap 736 128 R0
SYMATTR InstName C2
SYMATTR Value 10µ
SYMBOL res 880 112 R0
SYMATTR InstName R1
SYMATTR Value 24
SYMBOL voltage 208 256 R180
WINDOW 3 -574 -34 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value PWL repeat forever (0s 0V 5us 1V 10us 0V) endrepeat
SYMATTR InstName V2
SYMBOL cap 416 96 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C3
SYMATTR Value 1µ
SYMBOL ind 592 96 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName L2
SYMATTR Value 220µ
TEXT 8 0 Left 2 !.model FETsw sw(Vt={1-{Duty}} Ron=1u)
TEXT 648 0 Left 2 !.param Duty=1/(1+12V/24V)
TEXT -64 288 Left 2 !.tran 5m startup