Contents
What kind of network does the Wien bridge oscillator use?
The Wien Bridge Oscillator. The Wien Bridge Oscillator uses uses two RC networks connected together to produce a sinusoidal oscillator. In the RC Oscillator tutorial we saw that a number of resistors and capacitors can be connected together with an inverting amplifier to produce an oscillating circuit.
How to find the frequency of a bridge oscillator?
The frequency of oscillations is given by Determine the RC values of Wien bridge oscillator circuit for the operation at a frequency of 10 kHz if R = 100 K ohms and R1 = 1 K ohm. Given that f = 10 kHz, R = 100 K ohms, R1 = 1K ohm. The frequency of oscillations in Wien bridge oscillator is given as
How is gain control of JFET stabilized Wien bridge oscillator?
The above figure illustrates the automatic gain control of JFET stabilized Wien bridge oscillator. In this circuit, the amplifier gain is controlled by the components Rf, R3 and Q1. Depends on the gate voltage, the drain-source resistance is varied. This resistance is minimum with gate zero volts.
What are the resistors in a voltage tuned Wien bridge?
The voltage-tuned Wien network consists of an LSJ689 dual P-channel JFET as the pair of voltage controlled resistors. Drain-to-gate feedback resistors R3, R6 aid in linearizing the JFET’s effective resistance curve while R2, R5 make up a voltage divider for the gates of J689A and J689B.
When was the original Wien bridge circuit made?
In addition, it is possible to build Wien Bridge oscillators having very low levels of distortion compared with Phase Shift designs. The original Wien Bridge circuit shown in Fig. 3.3.1 was developed in 1891 for the purpose of accurately measuring capacitor values.
How to calculate the frequency of oscillations in a bridge oscillator?
The frequency of oscillations for the Wien Bridge Oscillator was given as 5200 Hertz. If resistors R1 = R2 and capacitors C1 = C2 and we assume a value for the feedback capacitors of 3.0nF, then the corresponding value of the feedback resistors is calculated as:
What can the Wien bridge be used for?
At this point it is possible to calculate the value of the unknown capacitor C1. A second use for the Wien Bridge is to measure an unknown frequency. If all the component values are known, the same bridge balancing procedure can be used to measure, by calculation, the frequency of the AC supplied.