WEIN BRIDGE OSCILLATOR

WIEN BRIDGE OSCILLATOR

• A Wein bridge oscillator is a type of oscillator that contributes to the generation of sine waves as an output.
• The Wein bridge oscillator can create a wide variety of frequencies. This entire system is built on the bridge circuit, which is made up of two capacitors and four resistors.
• The Wien bridge oscillator takes its name from the name of Max Karl Wien, a prominent physicist. In 1890, the Wien bridge oscillator was invented.

WIEN BRIDGE OSCILLATOR CIRCUIT DIAGRAM

Let's talk about how to build the Wein bridge oscillator.

• A resistor-capacitor (RC) circuit is used in the Wein bridge oscillator, which is a two-stage amplifier.
• In this bridge, the capacitor C1 is connected in series with the resistors R1 and R3, while the resistor R2 is connected in parallel with the capacitor C2.
• A tungsten lamp (Lp) is connected in parallel with the resistor R1.
• As a stabilizer, we use the resistors Lp and R3. This will aid in maintaining the output's amplitude.
• Two transistors, Q1 and Q2, were utilized. Q1 and Q2 both have a 360-degree phase.
• The first transistor, Q1, functions as an amplifier as well as an oscillator. Q2, on the other hand, functions as an inverter.
• In this schematic, the transistor, Q1, receives positive feedback from the series and parallel circuits, R1C1 and C2R2.
• The voltage divider provides negative feedback to the transistor Q2's input.

Wien Bridge Oscillator Operation

The Wien Bridge Oscillator works as follows:

• When a current runs through the Vcc, the bridge circuits begin to oscillate, utilizing the capacitor and resistor.
• A 360-degree phase shift is used to maintain correct positive feedback between the two transistors.
• Negative feedback guarantees that the circuit's output remains consistent. The lamp (Lp) and resistor (R3) aid in achieving negative feedback in the circuit.
• The Wien bridge oscillator is a type of oscillator based on sine waves.
• The first transistor flips the input sine wave 180 degrees, converting it to a cosine wave.
• However, the second transistor spins the cosine wave 180 degrees and converts it to a sine wave for output.
• If the current in the bridge increases during feedback circulation, it indicates that negative feedback is more prevalent.
• A tungsten bulb and resistors are used to keep the current from overflowing. As a result, we will obtain the original value via the output.

Applications of Wien Bridge Oscillators

The following are some of the most important uses for Wien Bridge oscillators:

• Creating frequencies in audio and RF circuits
• Signal testing and calibration
• Sine wave output function generators
• Phase-locked loop (PLL) circuits
• Medical instrumentation
• Tone generators and other audio devices

The Benefits of the Wien Bridge Oscillator

• We have now covered practically everything. Let us now look at some of the benefits of the Wien bridge oscillator.
• The Wien bridge oscillator provides the signals for filter testing.
• It has a high current output due to the presence of two transistors that amplify the current twice as rapidly.
• The Wien bridge oscillator has good frequency stability.
• Using the potentiometer, we may adjust the frequency of oscillation at any time.
• The Wien bridge oscillator generates a nice sine wave that is less distorted.

Wien Bridge Oscillator Drawbacks

• If anything has advantages, it must also have disadvantages. Let us go over some of the disadvantages of employing the Wien bridge oscillator.
• The Wien bridge oscillator requires a large number of tools, which are not always available.
• Because of the two transistors and several additional components, the circuit is complicated.
• The Wien bridge oscillator is incapable of producing very high frequencies.

IMAGE SOURCE (THUMBNAIL)