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