* SPICE netlist
Ra Vac Vsense 20.78k
L1 Vac N002 4mH
R2 N002 Isense 25
Rsense Isense 0 0.5952
Vac Vac 0 SINE(0 19.8 500)
Rb Vsense 0 1k
R4 Vfilter Vvo 1591.55
C1 Vfilter 0 10nF
XU2 N004 N001 Vsupply 0 Vvo LM324 ;pnba In+)In-)V+)V-)OUT
R8 N004 Vsense 10k
R9 N001 0 11k
R10 Vvo N001 11k
R11 Voff N004 11k
XOPAMP1 N003 Voff Vsupply 0 Vout LM324 ;pnba In+)In-)V+)V-)OUT
R3 N003 Vfilter 10k
R7 Vout N003 250k
C2 N004 0 3nF
C3 Vvo N001 3nF
V1 Vsupply 0 5
V2 Voff 0 2.1
.tran 0 0.104 0.1

* LTspice schematic (.asc)
Version 4
SHEET 1 2160 832
WIRE -296 -400 -328 -400
WIRE -200 -400 -232 -400
WIRE -328 -256 -328 -400
WIRE -296 -256 -328 -256
WIRE -200 -256 -200 -400
WIRE -200 -256 -216 -256
WIRE -920 -240 -1080 -240
WIRE -760 -240 -920 -240
WIRE -920 -208 -920 -240
WIRE -760 -208 -760 -240
WIRE -440 -128 -472 -128
WIRE -328 -128 -328 -256
WIRE -328 -128 -360 -128
WIRE 680 -128 568 -128
WIRE -328 -112 -328 -128
WIRE -296 -112 -328 -112
WIRE 808 -112 744 -112
WIRE 904 -112 808 -112
WIRE -1080 -96 -1080 -240
WIRE -920 -96 -920 -128
WIRE -200 -96 -200 -256
WIRE -200 -96 -232 -96
WIRE -168 -96 -200 -96
WIRE 8 -96 -40 -96
WIRE 168 -96 88 -96
WIRE 200 -96 168 -96
WIRE 600 -96 472 -96
WIRE 680 -96 600 -96
WIRE -296 -80 -328 -80
WIRE -760 -64 -760 -128
WIRE -664 -64 -760 -64
WIRE -440 -64 -472 -64
WIRE -328 -64 -328 -80
WIRE -328 -64 -360 -64
WIRE -328 -48 -328 -64
WIRE -280 -48 -328 -48
WIRE 168 -48 168 -96
WIRE -280 -32 -280 -48
WIRE -184 -32 -280 -32
WIRE -920 0 -920 -16
WIRE -840 0 -920 0
WIRE -184 0 -184 -32
WIRE -920 16 -920 0
WIRE -760 16 -760 -64
WIRE -328 48 -328 32
WIRE 600 48 600 -96
WIRE 664 48 600 48
WIRE 808 48 808 -112
WIRE 808 48 744 48
WIRE 168 64 168 16
WIRE -1080 112 -1080 -16
WIRE -920 112 -920 96
WIRE -920 112 -1080 112
WIRE -760 112 -760 96
WIRE -760 112 -920 112
WIRE -920 160 -920 112
FLAG -920 160 0
FLAG 168 64 0
FLAG -1080 -240 Vac
FLAG 1080 320 Vsupply
FLAG -264 -64 0
FLAG -264 -128 Vsupply
FLAG -472 -64 Vsense
FLAG -472 -128 0
FLAG -168 -96 Vvo
FLAG -328 48 Voff
FLAG -40 -96 Vvo
FLAG -664 -64 Vsense
FLAG 712 -80 0
FLAG 904 -112 Vout
FLAG 568 -128 Voff
FLAG 712 -144 Vsupply
FLAG 392 -96 Vfilter
FLAG 200 -96 Vfilter
FLAG -840 0 Isense
FLAG 936 336 Voff
FLAG -184 64 0
FLAG 1080 400 0
FLAG 936 416 0
SYMBOL res -776 -224 R0
SYMATTR InstName Ra
SYMATTR Value 20.78k
SYMBOL ind -936 -224 R0
SYMATTR InstName L1
SYMATTR Value 4mH
SYMBOL res -936 -112 R0
SYMATTR InstName R2
SYMATTR Value 25
SYMBOL res -936 0 R0
SYMATTR InstName Rsense
SYMATTR Value 0.5952
SYMBOL voltage -1080 -112 R0
SYMATTR Value SINE(0 19.8 500)
SYMATTR InstName Vac
SYMBOL res -776 0 R0
SYMATTR InstName Rb
SYMATTR Value 1k
SYMBOL res 104 -112 R90
SYMATTR InstName R4
SYMATTR Value 1591.55
SYMBOL cap 152 -48 R0
SYMATTR InstName C1
SYMATTR Value 10nF
SYMBOL Opamps/opamp2 -264 -160 R0
SYMATTR InstName U2
SYMATTR Value LM324
SYMBOL res -344 -80 R90
SYMATTR InstName R8
SYMATTR Value 10k
SYMBOL res -344 -144 R90
SYMATTR InstName R9
SYMATTR Value 11k
SYMBOL res -200 -272 R90
SYMATTR InstName R10
SYMATTR Value 11k
SYMBOL res -312 48 R180
SYMATTR InstName R11
SYMATTR Value 11k
SYMBOL Opamps/opamp2 712 -176 R0
SYMATTR InstName OPAMP1
SYMATTR Value LM324
SYMBOL res 488 -112 R90
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL res 760 32 R90
SYMATTR InstName R7
SYMATTR Value 250k
SYMBOL cap -200 0 R0
SYMATTR InstName C2
SYMATTR Value 3nF
SYMBOL cap -232 -416 R90
SYMATTR InstName C3
SYMATTR Value 3nF
SYMBOL voltage 1080 304 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL voltage 936 320 R0
SYMATTR InstName V2
SYMATTR Value 2.1