Version 4 SHEET 1 2680 712 WIRE 912 -128 560 -128 WIRE 1056 -128 1008 -128 WIRE 1200 -128 1056 -128 WIRE 1200 -64 1200 -128 WIRE 560 -32 560 -128 WIRE 576 -32 560 -32 WIRE 688 -32 656 -32 WIRE 720 -32 688 -32 WIRE 880 -32 800 -32 WIRE 960 -32 960 -64 WIRE 960 -32 880 -32 WIRE 352 -16 256 -16 WIRE 256 16 256 -16 WIRE 1056 16 1056 -128 WIRE 688 32 688 -32 WIRE 880 32 880 -32 WIRE 960 32 960 -32 WIRE 1200 32 1200 16 WIRE 256 128 256 96 WIRE 352 128 256 128 WIRE 688 128 688 96 WIRE 688 128 560 128 WIRE 880 128 880 96 WIRE 880 128 688 128 WIRE 960 128 960 96 WIRE 960 128 880 128 WIRE 1056 128 1056 96 WIRE 1056 128 960 128 WIRE 560 144 560 128 WIRE 256 160 256 128 WIRE 688 160 688 128 WIRE 880 160 880 128 WIRE 960 160 960 128 WIRE 1056 160 1056 128 WIRE 352 176 352 128 WIRE 1200 224 1200 208 WIRE 256 272 256 240 WIRE 352 272 256 272 WIRE 576 288 560 288 WIRE 688 288 688 224 WIRE 688 288 656 288 WIRE 720 288 688 288 WIRE 880 288 880 224 WIRE 880 288 800 288 WIRE 960 288 960 224 WIRE 960 288 880 288 WIRE 960 320 960 288 WIRE 560 384 560 288 WIRE 912 384 560 384 WIRE 1056 384 1056 240 WIRE 1056 384 1008 384 WIRE 1200 384 1200 304 WIRE 1200 384 1056 384 FLAG 352 176 0 FLAG 352 -16 +24V FLAG 352 272 -24V FLAG 560 -128 +24V FLAG 560 384 -24V FLAG 560 144 0 FLAG 1056 -128 +Vout FLAG 1056 384 -Vout FLAG 1200 32 0 FLAG 1200 208 0 FLAG 2400 -112 +24V SYMBOL voltage 256 0 R0 SYMATTR InstName V1 SYMATTR Value 24 SYMBOL voltage 256 144 R0 SYMATTR InstName V2 SYMATTR Value 24 SYMBOL res 672 -48 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value {RCUR} SYMBOL cap 672 32 R0 SYMATTR InstName C1 SYMATTR Value 100µ SYMBOL cap 672 160 R0 SYMATTR InstName C2 SYMATTR Value 100µ SYMBOL zener 896 96 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value TFZ18B SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 944 32 R0 SYMATTR InstName C3 SYMATTR Value 10µ SYMBOL cap 944 160 R0 SYMATTR InstName C4 SYMATTR Value 10µ SYMBOL res 1040 0 R0 SYMATTR InstName R5 SYMATTR Value 10k SYMBOL res 1040 144 R0 SYMATTR InstName R6 SYMATTR Value 10k SYMBOL npn 912 -64 R270 SYMATTR InstName Q1 SYMATTR Value BC847A SYMBOL pnp 912 320 M90 SYMATTR InstName Q2 SYMATTR Value BC857B SYMBOL res 1184 -80 R0 SYMATTR InstName R7 SYMATTR Value 18 SYMBOL res 1184 208 R0 SYMATTR InstName R8 SYMATTR Value 18 SYMBOL zener 896 224 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D2 SYMATTR Value TFZ18B SYMATTR Description Diode SYMATTR Type diode SYMBOL PowerProducts\\LT317A 2544 -112 R0 SYMATTR InstName U1 SYMBOL res 816 -48 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value {RCUR} SYMBOL res 816 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value {RCUR} SYMBOL res 672 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value {RCUR} TEXT 1512 -272 Left 2 ;Vout = Vin - Vzener\nR1 = R3 = Vout / (Izener + Ibase) \nP = Vout^2 / R1 (P is power dissipation of R1 and R3 in mW)\n \nV1 = 56V\nV2 = 56 - Vzener = 32V\nR1 = R3 = 32 / 20m = 1.6k (use 1.5k)\nP = 32² / 1.5k = 682mW = 0.68W (use 1W) TEXT 726 -266 Left 2 !.tran 0 0.1 0 0.0001 TEXT 1512 96 Left 2 ;https://www.youtube.com/watch?v=ur3nUWHKhtA TEXT 1512 120 Left 2 ;https://sound-au.com/project102.htm TEXT 1488 240 Left 2 !.ic V(+Vout)=0 V(-Vout)=0 TEXT 1496 304 Left 2 !.param RCUR=200