Version 4
SHEET 1 1820 680
WIRE 1024 -672 960 -672
WIRE -112 -528 -144 -528
WIRE -32 -528 -64 -528
WIRE 128 -528 112 -528
WIRE -144 -512 -144 -528
WIRE 224 -480 208 -480
WIRE 320 -480 304 -480
WIRE 400 -480 320 -480
WIRE 496 -480 400 -480
WIRE 592 -480 496 -480
WIRE 640 -480 592 -480
WIRE 784 -480 736 -480
WIRE 896 -480 864 -480
WIRE 944 -480 896 -480
WIRE 1040 -480 944 -480
WIRE 128 -464 112 -464
WIRE 400 -448 400 -480
WIRE 736 -448 736 -480
WIRE 1040 -448 1040 -480
WIRE 592 -432 592 -480
WIRE -144 -416 -144 -432
WIRE 1040 -336 1040 -368
WIRE 320 -320 320 -336
WIRE 400 -320 400 -368
WIRE 592 -320 592 -352
WIRE -192 -288 -192 -448
WIRE 752 -288 736 -288
WIRE 880 -288 832 -288
WIRE 944 -288 880 -288
WIRE 1040 -288 944 -288
WIRE 192 -272 144 -272
WIRE 736 -256 736 -288
WIRE 1040 -256 1040 -288
WIRE -64 -240 -64 -528
WIRE -16 -240 -64 -240
WIRE 1040 -144 1040 -176
WIRE -128 -128 -128 -144
WIRE -128 -112 -128 -128
WIRE -64 -112 -64 -240
WIRE -64 -112 -128 -112
FLAG -112 -528 o
IOPIN -112 -528 Out
FLAG -144 -416 0
FLAG -128 -128 f
FLAG 640 -480 fu
FLAG -192 -496 S
FLAG 736 -368 0
FLAG 896 -480 pd
FLAG 736 -176 0
FLAG 880 -288 pfu
FLAG 880 -672 0
FLAG 496 -128 0
FLAG 496 -208 vf
FLAG 208 -480 o
IOPIN 208 -480 In
FLAG 1024 -672 THD
IOPIN 1024 -672 Out
FLAG 192 -272 S
FLAG 1040 -336 0
FLAG 944 -336 0
FLAG 1040 -144 0
FLAG 944 -144 0
FLAG 400 -320 0
FLAG 320 -320 0
FLAG 592 -320 0
FLAG 496 -320 0
SYMBOL e -144 -528 R0
WINDOW 0 40 47 Left 0
WINDOW 3 37 75 Left 0
SYMATTR InstName E1
SYMATTR Value 1
SYMBOL SpecialFunctions\\modulate2 -128 -144 M270
WINDOW 3 -113 112 VLeft 0
WINDOW 123 -58 106 VLeft 0
WINDOW 39 -84 111 VLeft 0
WINDOW 0 51 29 Left 0
SYMATTR Value space=0 mark={2*f2}
SYMATTR Value2 Vhigh={percnt/100}
SYMATTR SpiceLine Vlow={-percnt/100}
SYMATTR InstName A1
SYMBOL res 320 -496 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value {Rq}
SYMBOL bv 736 -464 R0
WINDOW 3 -25 121 Left 0
SYMATTR Value V=(V(o)-V(fu))**2
SYMATTR InstName B1
SYMBOL res 768 -464 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL bv 736 -272 R0
WINDOW 0 29 43 Left 0
SYMATTR InstName B2
SYMATTR Value V=V(fu)**2
SYMBOL res 736 -272 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL bv 976 -672 R90
WINDOW 3 32 56 VTop 0
WINDOW 0 -32 56 VBottom 0
SYMATTR Value V=100*sqrt( V(pd)/V(pfu) )
SYMATTR InstName B3
SYMBOL bv 496 -224 R0
WINDOW 0 27 38 Left 0
SYMATTR InstName B4
SYMATTR Value V=V(f)*f2/1k
SYMBOL SpecialFunctions\\modulate2 -32 -528 R0
WINDOW 3 0 112 Left 0
WINDOW 123 0 130 Left 0
WINDOW 39 0 148 Left 0
WINDOW 0 53 -10 Left 0
SYMATTR Value space=0 mark={sf*f2}
SYMATTR Value2 Vhigh=1
SYMATTR SpiceLine Vlow=-1
SYMATTR InstName A3
SYMBOL bi 1040 -448 R0
WINDOW 3 13 86 Left 0
SYMATTR Value I=1/V(vf)*I(Vs)-I(Vs)
SYMATTR InstName Bc1
SYMBOL cap 928 -480 R0
WINDOW 3 23 53 Left 0
WINDOW 0 35 20 Left 0
SYMATTR Value {Cf/2}
SYMATTR InstName Cref1
SYMBOL voltage 944 -432 R0
WINDOW 0 -52 17 Left 0
WINDOW 3 -53 52 Left 0
SYMATTR InstName Vs
SYMATTR Value 0
SYMBOL bi 1040 -256 R0
WINDOW 3 13 86 Left 0
SYMATTR Value I=1/V(vf)*I(Vs1)-I(Vs1)
SYMATTR InstName Bc2
SYMBOL cap 928 -288 R0
WINDOW 3 23 53 Left 0
WINDOW 0 35 20 Left 0
SYMATTR Value {Cf}
SYMATTR InstName Cref2
SYMBOL voltage 944 -240 R0
WINDOW 0 -52 17 Left 0
WINDOW 3 -53 52 Left 0
SYMATTR InstName Vs1
SYMATTR Value 0
SYMBOL bi 400 -448 R0
WINDOW 3 -156 165 Left 0
SYMATTR Value I=1/V(vf)*I(Vs2)-I(Vs2)
SYMATTR InstName Bc3
SYMBOL cap 304 -480 R0
WINDOW 3 23 53 Left 0
WINDOW 0 35 20 Left 0
SYMATTR Value {Co}
SYMATTR InstName Cref3
SYMBOL voltage 320 -432 R0
WINDOW 0 -52 17 Left 0
WINDOW 3 -53 52 Left 0
SYMATTR InstName Vs2
SYMATTR Value 0
SYMBOL bi 592 -432 R0
WINDOW 3 -96 150 Left 0
SYMATTR Value I=V(vf)*I(Vs3)-I(Vs3)
SYMATTR InstName Bc4
SYMBOL voltage 496 -416 R0
WINDOW 0 -52 17 Left 0
WINDOW 3 -53 52 Left 0
SYMATTR InstName Vs3
SYMATTR Value 0
SYMBOL ind 480 -496 R0
SYMATTR InstName L2
SYMATTR Value {Lo}
SYMBOL Swept_Sine3 64 -240 R0
WINDOW 39 -100 75 Left 0
SYMATTR SpiceLine f1={f1} f2={f2} kd={kd} fmul={fmul} ct={ct}
SYMATTR InstName X1
TEXT 0 -336 Left 0 !.param f1=100/fmul f2=10k
TEXT -232 -576 Left 0 !.param percnt=0
TEXT -224 -632 Left 0 ;Enter\n2f-Distortion %:
TEXT 32 -648 Left 0 !.param  fo=1k*(1+eps)\n.param Zo=1k Lo=Zo/2/pi/fo Q=5\n.param Co=1/4/pi**2/fo**2/Lo Rq=Zo*Q
TEXT -220 -684 Left 0 !.tran 0 {To} {kd}
TEXT 752 -544 Left 0 !.param Cf=3u
TEXT 576 -536 Left 0 ;fundamental\nvoltage
TEXT 512 -224 Left 0 ;V=kHz
TEXT 784 -120 Left 0 !.ic V(pfu)=1
TEXT 400 -648 Left 0 !.param eps=2u
TEXT 288 -704 Left 0 ;Trick: eps can be used to adjust "virtual"\nresonance frequency at big tmaxstep!
TEXT -40 -496 Left 0 ;sample forcing
TEXT -200 -744 Left 0 ;Continuous Sweep type THD-meter using a tracking filter and time optimal frequency sweep.
TEXT 48 -112 Left 0 !.param kd=15/f1 ;time to start f-sweep
TEXT 48 -80 Left 0 !.param To=kd+7.65
TEXT 72 -696 Left 0 !.save V(thd) V(f)
TEXT 912 -544 Left 0 ;non charge-preserving\ncontrolled caps
TEXT 1024 -712 Left 0 ;in %
TEXT 48 -48 Left 0 !.param fmul=sqrt(2)
TEXT 288 -80 Left 0 ;This THD-meter could be adjusted for much higher precision ("internal" THD)\nbut at the cost of slower sweep speed, i.e. longer simulation time\n(adjust ct and sample forcing sf).\nPresently it is set to 0.1% which is mainly due to sweep speed.
TEXT 48 -16 Left 0 !.param sf=15 ct=32u