Version 4 SHEET 1 1088 680 WIRE -192 -96 -208 -96 WIRE -64 -96 -64 -112 WIRE -64 -96 -112 -96 WIRE 256 -96 -64 -96 WIRE 384 -96 336 -96 WIRE 400 -96 384 -96 WIRE 480 -96 464 -96 WIRE 544 -96 480 -96 WIRE 688 -96 544 -96 WIRE 688 -64 688 -96 WIRE -208 -48 -208 -96 WIRE 544 -32 544 -96 WIRE -64 -16 -96 -16 WIRE -48 -16 -64 -16 WIRE 176 -16 176 -32 WIRE 208 -16 176 -16 WIRE 304 -16 288 -16 WIRE 432 -16 304 -16 WIRE -384 0 -384 -16 WIRE -384 0 -416 0 WIRE 304 0 304 -16 WIRE -416 16 -416 0 WIRE -96 32 -96 -16 WIRE -384 48 -384 0 WIRE -368 48 -384 48 WIRE -128 48 -144 48 WIRE -64 48 -64 -16 WIRE -48 48 -64 48 WIRE 208 48 176 48 WIRE 480 48 480 -96 WIRE -128 64 -128 48 WIRE 208 64 208 48 WIRE 688 64 688 16 WIRE 608 80 608 64 WIRE 304 96 304 80 WIRE 384 96 384 -96 WIRE 544 96 544 48 WIRE 576 96 544 96 WIRE -416 112 -416 96 WIRE -368 112 -416 112 WIRE -128 112 -144 112 WIRE -48 112 -64 112 WIRE 192 112 176 112 WIRE 656 112 640 112 WIRE -416 128 -416 112 WIRE -128 128 -128 112 WIRE -128 128 -384 128 WIRE 432 128 432 -16 WIRE 576 128 432 128 WIRE 192 144 192 112 WIRE 192 144 -128 144 WIRE 544 144 544 96 WIRE -384 176 -384 128 WIRE -368 176 -384 176 WIRE -144 176 -144 144 WIRE -128 176 -128 144 WIRE -128 176 -144 176 WIRE -96 176 -96 112 WIRE -64 176 -64 112 WIRE -64 176 -96 176 WIRE -48 176 -64 176 WIRE 336 176 176 176 WIRE -416 224 -416 208 WIRE -384 224 -384 176 WIRE -384 224 -416 224 WIRE -48 240 -64 240 WIRE 480 240 480 112 WIRE 544 240 544 224 WIRE 544 240 480 240 WIRE 608 240 608 144 WIRE 608 240 544 240 WIRE -96 256 -96 176 WIRE 384 256 384 192 WIRE 480 256 480 240 WIRE -64 288 -64 240 WIRE 656 288 656 112 WIRE 656 288 -64 288 WIRE -416 304 -416 288 WIRE -96 336 -96 320 FLAG -128 64 0 FLAG 208 64 0 FLAG -208 -48 0 FLAG -416 304 0 FLAG -96 336 0 FLAG 384 256 0 FLAG 480 256 0 FLAG 688 64 0 FLAG 304 96 0 FLAG -64 -112 +5 FLAG 608 64 +5 FLAG 176 -32 +5 FLAG -384 -16 +5 FLAG -144 240 +5 FLAG 176 240 +5 FLAG -48 -16 +5 SYMBOL Misc\\NE555 -256 144 M0 SYMATTR InstName U1 SYMBOL Misc\\NE555 64 144 M0 SYMATTR InstName U2 SYMBOL Misc\\battery -96 -96 R90 WINDOW 0 -32 56 VBottom 0 WINDOW 3 39 48 VTop 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL res -432 0 R0 WINDOW 0 -39 46 Left 0 WINDOW 3 -46 85 Left 0 SYMATTR InstName R1 SYMATTR Value 56k SYMBOL res -432 112 R0 WINDOW 0 -37 42 Left 0 WINDOW 3 -49 80 Left 0 SYMATTR InstName R2 SYMATTR Value 4.7k SYMBOL cap -432 224 R0 WINDOW 0 -34 17 Left 0 WINDOW 3 -51 60 Left 0 SYMATTR InstName C1 SYMATTR Value .001µ SYMBOL res -112 16 R0 WINDOW 0 -19 19 Left 0 WINDOW 3 25 50 Left 0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL cap -112 256 R0 WINDOW 0 -15 10 Left 0 WINDOW 3 -60 54 Left 0 SYMATTR InstName C2 SYMATTR Value .0022µ SYMBOL ind 240 -80 R270 WINDOW 0 36 55 VTop 0 WINDOW 3 -1 59 VBottom 0 SYMATTR InstName L1 SYMATTR Value 470µ SYMATTR SpiceLine Ipk=2 Rser=.81 SYMBOL schottky 400 -80 R270 WINDOW 0 37 32 VTop 0 WINDOW 3 -7 36 VBottom 0 SYMATTR InstName D1 SYMATTR Value 1N5819 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 464 48 R0 WINDOW 0 -27 11 Left 0 WINDOW 3 22 10 Left 0 SYMATTR InstName C3 SYMATTR Value 220µ SYMBOL res 528 -48 R0 WINDOW 3 33 49 Left 0 WINDOW 0 -29 65 Left 0 SYMATTR Value 10k SYMATTR InstName R5 SYMBOL res 528 128 R0 WINDOW 0 -29 62 Left 0 WINDOW 3 27 84 Left 0 SYMATTR InstName R6 SYMATTR Value 2.2k SYMBOL res 672 -80 R0 SYMATTR InstName RL SYMATTR Value 220 SYMBOL res 288 -16 R0 WINDOW 0 -30 58 Left 0 WINDOW 3 -31 93 Left 0 SYMATTR InstName R8 SYMATTR Value 1k SYMBOL res 304 -32 R90 WINDOW 0 59 93 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R9 SYMATTR Value 1k SYMBOL Opamps\\LT1797 608 48 R0 SYMATTR InstName U3 SYMBOL nmos 336 96 R0 SYMATTR InstName M1 SYMATTR Value IRF7455 TEXT -376 -104 Left 0 !.tran 10m TEXT -240 -264 Left 0 ;This circuit is from Schuler's Experiments Manual, 7th ed., pages 297-298 but \nhas been tweaked for better efficiency, less output ripple and a faster startup. TEXT -184 -200 Left 0 ;An N-channel MOSFET is used, a Schottky rectifier, a larger filter \ncapacitor and L1 is a Coilcraft RFB1010-471 with low resistance. TEXT -280 376 Left 0 ;Run the simulation and click inside L1 to plot the current. Hold down the left\nmouse button and draw a box around the current waveform from 4.5 ms\nto 10 ms. Right click the waveform label I(L1) to determine the average input\ncurrent (210 mA). The input power is 5V x 210mA = 1.05 Watts.\nThe output power is 13.9V X 13.9V/220 Ohms = 0.878 Watts.\nThe efficiency (of the switching section) is 0.878W/1.05W = 84 %