Table of Contents
What are Barkhausen conditions for oscillation?
Barkhausen Criteria The Barkhausen criterion states that: The loop gain is equal to unity in absolute magnitude, that is, | β A | = 1 and Page 2 • The phase shift around the loop is zero or an integer multiple of 2π radian (180°) i.e. The product β A is called as the “loop gain”.
How does Colpitts oscillator work?
Oscillator is an amplifier with the positive feedback and it converts DC input signal into AC output waveform with certain variable frequency drive and certain shape of output waveform (like sine wave or square wave, etc) by using the positive feedback instead of input signal.
What is the criterion to be followed in obtaining oscillator output?
Gain in Oscillators: The oscillator gain must equal one (Aβ = 1–180°) at the oscillation frequency. The circuit becomes stable when the gain exceeds one and oscillations cease. When the gain exceeds one with a phase shift of –180°, the active device non-linearity reduces the gain to one.
Which of the following is not a sinusoidal oscillator?
Which of the following is not an example of sinusoidal oscillator? Explanation: A blocking oscillator is a non-sinusoidal oscillator. It produces a free running signal-square shaped and requires only a resistor, transformer and one amplifying element to work.
Which component of Colpitts oscillator is used in feedback system?
Which component of Colpitts oscillator is used in feedback system? Explanation: A capacitor with a center tap or simply two capacitors in parallel to an inductor, acting as a voltage divider, acts as the feedback system, providing feedback to the base of the amplifying transistor.
Is the active element of the Colpitts oscillator?
The active element used in Colpitts oscillator is transistor and it is used for amplification of weak oscillator signals. Solution: RFC choke present in Colpitts oscillator is to provide high reactance to AC oscillation and low reactance to DC supply to improve performance.
What is an oscillator give condition for oscillations?
Oscillator requires external input signal for its operation. Principle of Oscillators. An oscillator consists of an amplifier and a feedback network. Now, let us see which basic components are required to obtain oscillations. ‘Active device’ either Transistor or Op Amp is used as an amplifier.
Which is better Hartley or Colpitts oscillator?
In Colpitts oscillator, the capacitive voltage divider setup in the tank circuit works as the feed back source and this arrangement gives better frequency stability when compared to the Hartley oscillator which uses an inductive voltage divider setup for feedback.
Which of the following oscillators does not produce a sinusoidal output waveform?
relaxation oscillator
A relaxation oscillator is a nonlinear electronic oscillator circuit that produces a non-sinusoidal repetitive output signal, such as a triangle wave or square wave outputs by discharging of output voltages through the capacitor.