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Trouble simulating a Wein Bridge Oscillator in LTspice

Discussion in 'Electronic Basics' started by dave.harper, Jan 19, 2009.

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  1. dave.harper

    dave.harper Guest

    I'm trying to simulate a Wein Bridge Oscillator in LTspice (I'm new to
    it), and haven't managed to get it to work. I've simulated a few
    other oscillators without any problems, but for some reason this one
    is not oscillating. Maybe it has something to do with the way I set
    up the op amp (or the one I selected)? Below is the .asc file I've
    used to put it together. Any insight is greatly appreciated!

    Thanks!
    Dave

    Version 4
    SHEET 1 928 680
    WIRE 48 -320 -64 -320
    WIRE 176 -240 48 -240
    WIRE 64 -208 -144 -208
    WIRE -144 -192 -144 -208
    WIRE 64 -192 64 -208
    WIRE -64 -176 -64 -320
    WIRE 32 -176 -64 -176
    WIRE 176 -160 176 -240
    WIRE 176 -160 96 -160
    WIRE 32 -144 -16 -144
    WIRE 64 -80 64 -128
    WIRE 176 -80 176 -160
    WIRE -144 -64 -144 -112
    WIRE 176 32 176 0
    WIRE -16 112 -16 -144
    WIRE 176 112 176 96
    WIRE 176 112 -16 112
    WIRE 176 128 176 112
    WIRE -16 144 -16 112
    WIRE -16 240 -16 208
    WIRE 80 240 -16 240
    WIRE 176 240 176 208
    WIRE 176 240 80 240
    WIRE 80 272 80 240
    FLAG -144 -64 0
    FLAG 64 -80 0
    FLAG 80 272 0
    SYMBOL voltage -144 -208 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -66 54 Left 0
    WINDOW 3 47 51 Left 0
    SYMATTR InstName V1
    SYMATTR Value 5
    SYMBOL res 32 -336 R0
    SYMATTR InstName R1
    SYMATTR Value 20k
    SYMBOL cap 160 32 R0
    SYMATTR InstName C1
    SYMATTR Value .01µ
    SYMBOL res 160 112 R0
    SYMATTR InstName R2
    SYMATTR Value 10k
    SYMBOL cap -32 144 R0
    SYMATTR InstName C2
    SYMATTR Value .01µ
    SYMBOL res 160 -96 R0
    SYMATTR InstName R3
    SYMATTR Value 10k
    SYMBOL Opamps\\LT1024 64 -224 R0
    SYMATTR InstName U1
    TEXT -104 -360 Left 0 !.tran 0 .005 0 .000001 startup
     
  2. I'm trying to simulate a Wein Bridge Oscillator in LTspice (I'm new to
    it), and haven't managed to get it to work. I've simulated a few
    other oscillators without any problems, but for some reason this one
    is not oscillating. Maybe it has something to do with the way I set
    up the op amp (or the one I selected)? Below is the .asc file I've
    used to put it together. Any insight is greatly appreciated!

    Thanks!
    Dave


    Hello Dave,

    When you run circuits with single supply, you jave to
    choose the right opamp and you have to provide a
    reference to VCC/2. Please try my example below.

    http://www.ecircuitcenter.com/Circuits/opwien/opwien.htm

    Best regards,
    Helmut


    Version 4
    SHEET 1 928 680
    WIRE 176 -480 128 -480
    WIRE 272 -480 240 -480
    WIRE 128 -400 128 -480
    WIRE 176 -400 128 -400
    WIRE 272 -400 272 -480
    WIRE 272 -400 240 -400
    WIRE -128 -304 -160 -304
    WIRE -16 -304 -48 -304
    WIRE 16 -304 -16 -304
    WIRE 128 -304 128 -400
    WIRE 128 -304 96 -304
    WIRE 160 -304 128 -304
    WIRE 272 -304 272 -400
    WIRE 272 -304 240 -304
    WIRE 96 -192 96 -208
    WIRE -16 -176 -16 -304
    WIRE 64 -176 -16 -176
    WIRE 224 -160 128 -160
    WIRE 272 -160 272 -304
    WIRE 272 -160 224 -160
    WIRE 64 -144 -16 -144
    WIRE 272 -112 272 -160
    WIRE -384 -80 -384 -128
    WIRE -336 -80 -384 -80
    WIRE -224 -80 -256 -80
    WIRE -144 -80 -144 -128
    WIRE -144 -80 -224 -80
    WIRE 96 -80 96 -128
    WIRE -144 -48 -144 -80
    WIRE -384 -32 -384 -80
    WIRE -224 -32 -224 -80
    WIRE 272 16 272 -32
    WIRE -384 80 -384 48
    WIRE -224 80 -224 48
    WIRE -144 80 -144 16
    WIRE -16 112 -16 -144
    WIRE 112 112 -16 112
    WIRE 272 112 272 80
    WIRE 272 112 112 112
    WIRE 272 128 272 112
    WIRE -16 144 -16 112
    WIRE -16 240 -16 208
    WIRE -16 240 -112 240
    WIRE 272 240 272 208
    WIRE 272 240 -16 240
    FLAG -384 80 0
    FLAG 96 -80 0
    FLAG -384 -128 +5V
    FLAG 96 -208 +5V
    FLAG -112 240 +2.5V
    FLAG -160 -304 +2.5V
    FLAG 112 112 in1
    FLAG 224 -160 out
    FLAG -144 80 0
    FLAG -224 80 0
    FLAG -144 -128 +2.5V
    SYMBOL voltage -384 -48 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -66 54 Left 0
    WINDOW 3 47 51 Left 0
    SYMATTR InstName V1
    SYMATTR Value 5
    SYMBOL res 0 -288 R270
    WINDOW 0 32 56 VTop 0
    WINDOW 3 0 56 VBottom 0
    SYMATTR InstName R1
    SYMATTR Value 12k
    SYMBOL cap 256 16 R0
    SYMATTR InstName C1
    SYMATTR Value .01µ
    SYMBOL res 256 112 R0
    SYMATTR InstName R2
    SYMATTR Value 10k
    SYMBOL cap -32 144 R0
    SYMATTR InstName C2
    SYMATTR Value .01µ
    SYMBOL res 256 -128 R0
    SYMATTR InstName R3
    SYMATTR Value 10k
    SYMBOL Opamps\\LT1797 96 -224 R0
    SYMATTR InstName U3
    SYMBOL res -144 -288 R270
    WINDOW 0 32 56 VTop 0
    WINDOW 3 0 56 VBottom 0
    SYMATTR InstName R5
    SYMATTR Value 10k
    SYMBOL res 144 -288 R270
    WINDOW 0 32 56 VTop 0
    WINDOW 3 0 56 VBottom 0
    SYMATTR InstName R4
    SYMATTR Value 10k
    SYMBOL diode 176 -384 R270
    WINDOW 0 32 32 VTop 0
    WINDOW 3 0 32 VBottom 0
    SYMATTR InstName D1
    SYMATTR Value 1N4148
    SYMBOL diode 240 -496 R90
    WINDOW 0 0 32 VBottom 0
    WINDOW 3 32 32 VTop 0
    SYMATTR InstName D2
    SYMATTR Value 1N4148
    SYMBOL res -352 -64 R270
    WINDOW 0 32 56 VTop 0
    WINDOW 3 0 56 VBottom 0
    SYMATTR InstName R6
    SYMATTR Value 1k
    SYMBOL res -240 -48 R0
    SYMATTR InstName R7
    SYMATTR Value 1k
    SYMBOL polcap -160 -48 R0
    SYMATTR InstName C3
    SYMATTR Value 10µ
    TEXT -440 -464 Left 0 !.tran 0 10m 0 1u
    TEXT -440 -424 Left 0 !.ic V(in1)=2.7
    TEXT -440 -512 Left 0 ;Wien Oscillator With Single Supply
     
  3. dave.harper

    dave.harper Guest

    Fantastic, thanks! It works like a charm. I'll be studying this and
    probably breadboarding it tonight.

    Thanks for the help!
    Dave
     
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