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

Automatic meter reading and remote meter reading, Automatic Meter Reading a...

Automatic Meter Reading and Remote Meter Reading Automatic Meter Reading (AMR) and Remote Meter Reading (RMR) elaborate several systems which permit meters to be checked with

Working principle of ultrasonic machine, Illustrate the working principle, ...

Illustrate the working principle, equipment used,process characteristic, advantage and disadvantage of water jet machine (WJM) (a) Illustrtae the working principle of ultrasonic

Find the slip and the rotor frequency at full load, Q. A three-phase, 50-Hz...

Q. A three-phase, 50-Hz induction motor has a full load speed of 700 r/min and a no-load speed of 740 r/min. (a) How many poles does the machine have? (b) Find the slip and t

Single- and three-phase systems, Ac power has significant practical advanta...

Ac power has significant practical advantages over dc power in generation, transmission, and distribution. One major drawback of the single-phase circuit is the oscillatory nature

Stc set carry instruction, STC Set Carry Instruction This instruction ...

STC Set Carry Instruction This instruction  sets   the carry  flag  to 1. The  instruction format is STC Flags except carry no other  flags are affected

Discuss the need of peripheral component interconnect bus, Discuss the need...

Discuss the need of PCI bus. Peripheral Component Interconnect (PCI): It was developed by Intel and introduced in 1993 year. This is geared particularly to fifth- and sixth-

Sketch the phasor diagram, Q. A balanced delta-connected load with a per-ph...

Q. A balanced delta-connected load with a per-phase impedance of 12 + j9  is supplied by a 173-V, 60-Hz three-phase source. (a) Determine the line current, the power factor, th

Sommerfield’s free electron theory, Write down basic postulates of sommerfi...

Write down basic postulates of sommerfield’s free electron gas model. Show that the number of energy states per unit energy is given by g(E) = 4Rv/h 3 (2m) 3/2 E 1/2 .  What is

Define short lines, Define Short Lines? For short power lines (up to 50...

Define Short Lines? For short power lines (up to 50 miles; 80 km),  the effects of the shunt capacitance and leakage resistance are negligible. Hence the line may be represente

Digital controller for a steam-turbine driven generator, Q. Digital control...

Q. Digital controller for a steam-turbine driven generator? Figure illustrates the basic elements of a minicomputer system in terms of a block diagram for speed and voltage con

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