Version 4 SHEET 1 3784 1092 WIRE -480 64 -512 64 WIRE -240 64 -480 64 WIRE -48 64 -240 64 WIRE 0 64 -48 64 WIRE 368 64 96 64 WIRE 416 64 368 64 WIRE 544 64 496 64 WIRE 688 64 544 64 WIRE 768 64 688 64 WIRE 800 64 768 64 WIRE -48 96 -48 64 WIRE 368 96 368 64 WIRE 544 96 544 64 WIRE 768 96 768 64 WIRE -480 128 -480 64 WIRE 368 176 368 160 WIRE 544 176 544 160 WIRE -48 192 -48 176 WIRE 48 192 48 128 WIRE 48 192 -48 192 WIRE 768 192 768 176 WIRE -240 224 -240 64 WIRE -48 224 -48 192 WIRE -480 256 -480 208 WIRE 128 272 128 256 WIRE 464 272 464 256 WIRE 688 352 688 64 WIRE 128 384 128 352 WIRE 160 384 128 384 WIRE 464 384 464 352 WIRE 464 384 384 384 WIRE 544 384 464 384 WIRE -48 416 -48 304 WIRE 384 416 384 384 WIRE 544 416 544 384 WIRE 128 464 128 384 WIRE 128 464 16 464 WIRE 176 464 128 464 WIRE 288 464 288 448 WIRE 288 464 256 464 WIRE 320 464 288 464 WIRE 640 464 640 448 WIRE 640 464 608 464 WIRE 688 464 688 432 WIRE 688 464 640 464 WIRE 688 496 688 464 WIRE 128 512 128 464 WIRE 384 560 384 512 WIRE 384 560 192 560 WIRE -240 576 -240 304 WIRE -240 576 -432 576 WIRE -192 576 -240 576 WIRE 384 592 384 560 WIRE -240 608 -240 576 WIRE -192 608 -192 576 WIRE -240 688 -240 672 WIRE -192 688 -192 672 WIRE -192 688 -240 688 WIRE -48 688 -48 512 WIRE -48 688 -192 688 WIRE 128 688 128 608 WIRE 128 688 -48 688 WIRE 384 688 384 672 WIRE 384 688 128 688 WIRE 544 688 544 512 WIRE 544 688 384 688 WIRE 688 688 688 576 WIRE 688 688 544 688 WIRE 128 704 128 688 WIRE -432 768 -432 576 WIRE -432 768 -480 768 WIRE 176 768 -432 768 WIRE 288 768 288 464 WIRE 288 768 256 768 FLAG -480 256 0 FLAG 368 176 0 FLAG 544 176 0 FLAG 768 192 0 FLAG 128 704 0 FLAG -480 768 setpoint FLAG 640 448 IN- IOPIN 640 448 In FLAG 288 448 IN+ IOPIN 288 448 In FLAG 160 384 OUT IOPIN 160 384 Out FLAG -512 64 Vin IOPIN -512 64 In FLAG 464 256 Vin FLAG 800 64 Vout IOPIN 800 64 Out FLAG 128 256 Vin SYMBOL res -64 80 R0 SYMATTR InstName R1 SYMATTR Value 4k7 SYMBOL voltage -480 112 M0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value PULSE(16 16 0 0 0 1.5m 3m) SYMBOL ind 512 48 R90 WINDOW 0 5 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName L1 SYMATTR Value 470µ SYMATTR SpiceLine Rser=2.5 SYMBOL schottky 384 160 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 528 96 R0 SYMATTR InstName C1 SYMATTR Value 100µ SYMATTR SpiceLine Rser=50m SYMBOL res 752 80 R0 SYMATTR InstName R3 SYMATTR Value 400 SYMBOL npn 192 512 M0 SYMATTR InstName Q2 SYMATTR Value BC546B SYMBOL pnp 608 512 R180 SYMATTR InstName Q3 SYMATTR Value BC556B SYMBOL pnp 320 512 M180 SYMATTR InstName Q4 SYMATTR Value BC556B SYMBOL res 448 256 R0 SYMATTR InstName R5 SYMATTR Value 10k SYMBOL res 672 336 R0 SYMATTR InstName R6 SYMATTR Value 10k SYMBOL res 672 480 R0 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL res 272 752 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 4k7 SYMBOL pnp 96 128 M270 SYMATTR InstName Q1 SYMATTR Value BC327-40 SYMBOL res -64 208 R0 SYMATTR InstName R2 SYMATTR Value 4k7 SYMBOL res 160 448 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R10 SYMATTR Value 1meg SYMBOL res 400 576 M0 SYMATTR InstName R18 SYMATTR Value 1k SYMBOL npn 16 416 M0 SYMATTR InstName Q6 SYMATTR Value BC546B SYMBOL res 112 256 R0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL zener -224 672 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D4 SYMATTR Value BZX84C6V2L SYMATTR Description Diode SYMATTR Type diode SYMBOL res -256 208 R0 SYMATTR InstName R12 SYMATTR Value 10k SYMBOL cap -208 672 M180 WINDOW 0 24 56 Left 2 WINDOW 3 24 8 Left 2 SYMATTR InstName C2 SYMATTR Value 10n SYMATTR SpiceLine Rser=50m TEXT -864 840 Left 2 !.tran 0 6m 3m uic TEXT 128 -72 Left 2 ;This circuit lacks current limiting for switching transistor during startup TEXT 336 744 Left 2 ;Comparator with positve feedback (Schmitt-Trigger) TEXT 128 -40 Left 2 ;Efficiency ~= 76%