What is barkhausen criterion, Electrical Engineering

Assignment Help:

Q. What is Barkhausen criterion? Why is the value of Ab kept slightly greater than 1?

The condition |Ab| = 1 is called the Barkhausen criterion. It implies that when |Ab| = 1, there exists an output voltage even in the absence of any externally applied signal. If |Ab| = 1, the feedback voltage is sufficient for producing self sustained oscillations. If Ab = 1 precisely, then after sometime it is found that Ab will either become lower or higher than unity. This is due to the change in the characteristics of the active devices with voltage, temperature or age. If Ab < 1, the removal of input signal source will result in dying out of oscillations. If Ab > 1, then the amplitude of the oscillations will continue to increase until clipping occurs because of saturation and cut-off causing the voltage gain to reduce.

Hence, Ab is kept slightly larger than unity so that any variation in circuit parameters may not cause Ab to become less than unity.


Related Discussions:- What is barkhausen criterion

Define the property under which resistance of metals vanish, The property d...

The property due to which the resistance of some metal or compound vanishes under certain conditions is (A) Semi conductivity.                     (B) Super conductivity.

Supercomputer -introduction to microprocessors , Supercomputer The lar...

Supercomputer The largest  fastest and most  powerful  are called supercomputers. Supercomputers are mainly used for  weather forecasting remote  sensing image processing, biom

Explain the terms dielectric constant and dielectric loss, Explain the term...

Explain the terms dielectric constant and dielectric loss. Dielectric Constant or Permittivity: all insulating materials possess an electrical capacitance. The capacitance of

Digital electronic, What are the advantages of wired-AND connection of digi...

What are the advantages of wired-AND connection of digital IC

Clc filter, CLC or π Filter The above diagram displays CLC or π ty...

CLC or π Filter The above diagram displays CLC or π type filter, which mainly contains a capacitor filter, followed through LC section. This filter offers a quite smooth o

Standby mode, Standby mode:In this mode, one processor is active and other ...

Standby mode:In this mode, one processor is active and other is on standby, both software and hardware wise. Standby processor brought online when active processor fails. A vital r

Thevenins theorem, How to solve questions on thevenin theorem

How to solve questions on thevenin theorem

Alternator, How can I design alternator?

How can I design alternator?

Signals in noise, Signals in Noise: Let us now consider a weak informat...

Signals in Noise: Let us now consider a weak information signal that is to be amplified by a noisy amplifier. The signal-to-noise ratio (SNR), usually expressed in decibels, be

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd