Wien Bridge
Transcript of Wien Bridge
8/3/2019 Wien Bridge
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Abstract — Design and implementation of a Wien Bridge
oscillator with frequency at 36.75 kHz.
[1] INTRODUCTION
A Wien bridge oscillator is a kind of electronic oscillator
that produces sine waves and can create a large range of
frequencies. In 1891, Max Wien originally developed the
concept of this circuit based on an electrical network. The
bridge comprised four resistors and two capacitors, but Wien
did not have a means of developing electronic gain so a
workable model could not be realized.
This concept was then developed and perfected by William
Hewlett in his 1939 Stanford University master’s degree
thesis. William Hewlett and David Packard founded Hewlett-
Packard whose first product was a precision sine waveoscillator based on the Wien bridge. This was one of the first
instruments to produce such low distortion.
Figure : Generalized schematic of a Wien bridge oscillator.
[2] METHODOLOGY
To get the component values for the oscillator, we assume
that R1 and R2 are equal, and so are C1 and C2, as seen in
Equation 1. Then we get the frequency of oscillation, from
Equation 2.
R1=R2=R; C1=C2=C (1)
f=12πRC=36.75kHz (2)At R = 1k,C=12πR36.75k=4.33 nF use 0.0047uF standard
For a gain of 2, and setting R4=1kΩ,
Av=R3R4
R3=R4 x Av=2kΩ
Figure : Actual circuit schematic for the Wien bridgeoscillator operating at 36.75 kHz.
Figure : Actual setup for the Wien bridge oscillator.
[3] RESULTS
Figure : Simulated output of the Wien bridge oscillator.
Figure : Actual output waveform of the Wien bridgeoscillator.
[4] REFERENCES
[1] Close-Circuit.com. Wien Bridge Oscillator. n.d.
<http://www.close-circuit.com/wein-bridge-
oscillator.html>.
Design Problem 3: Wien Bridge Oscillator