Total harmonic distortion, Electrical Engineering

Assignment Help:

Q. Explain the term total harmonic distortion. Describes the functionary of a total harmonic distortion analyzer.

Total Harmonic Distortion: Nonlinear behaviors of circuit elements introduce harmonics in the output waveform and the resultant distortion. A nonlinear system produces harmonics of an input sine wave, the harmonics consisting of sine waves with frequencies which are multiples of the fundamental of the input signal. Total harmonic distortion is measured in terms of the harmonic content of the wave, as given by equation.

     A measure of distortion represented by a particular harmonic is simply the ratio of amplitude of harmonic to that of the fundamental harmonic distortion is then represented.

 Harmonic Distortion Analyzer: a harmonic distortion analyzer which is used to measure THD. The signal source has very low distortion and this can be checked by reading its output distortion by connecting directly into the analyzer. The signal from the source is fed into the amplifier under test. The generates harmonics and the original frequency (fundamental). The fundamental frequency is removed by the notch filter.

        In the manual system of the switch SW is first placed imposition and the total content of fundamental and harmonics is measured. Then the switch is moved to position to measure just the harmonics. The value of THD is then fond from equation.

 The meter can be calibrated by putting the switch in position and adjusting the reading for full scale deflection. Wight the switch in position the meter reading is now proportional to THD.

  Shows an alternative arrangement, where the values of are read simultaneously and their ratio calculated and displayed as THD on the indicator. For good accuracy the notch filter must have excellent rejection and high pass characteristics. It should attenuate the fundamental by 100 db or more and the harmonics by less than 1dB. The filter also needs to be tuned accurately to the fundamental of the signal source. This is difficult to achieve manually and most distortion analyzer do this automatically. A common from of notch filter is Wien Bridge. The balances at one frequency only and at this frequency the output voltage at the frequency only and at this frequency the output voltage at the bridge null detector is minimum.


Related Discussions:- Total harmonic distortion

Voltmeter transistor, explain basic working of voltmeter transistor

explain basic working of voltmeter transistor

Finite state machine, the tutorial assignment is part of my thesis work and...

the tutorial assignment is part of my thesis work and i need help in it please

Emi, what is direct reading probe

what is direct reading probe

Composition of fet, Composition of FET The FET (field-effect transisto...

Composition of FET The FET (field-effect transistor) can be constructed from several semiconductors, silicon being by far the most common. Several FETs are made with conventio

Digital control system, block diagram of digital control system and explain...

block diagram of digital control system and explain each block

Pulse width modulation, Change the brightness of the most beneficial illumi...

Change the brightness of the most beneficial illuminated LED to represent voltages among the ranges so that if the value is half way among the range then the LED should be 50% brig

Explain series capacitors, Explain Series capacitors These are connecte...

Explain Series capacitors These are connected in series with the line conductors and are used to reduce the inductive reactance of long transmission lines and hence the voltage

ADC and DAC design, I''m trying to design ADC using MAX1198 and DAC using I...

I''m trying to design ADC using MAX1198 and DAC using IDAC in Multisim 12 but none of them are working. I need some help in this regard

Evaluate reference voltage, Q. Consider the 4-bit R-2R ladder D/A converter...

Q. Consider the 4-bit R-2R ladder D/A converter with V ref =-10 V. Determine the analog output voltage when the binary input code is 1100. Also, find what reference voltage is to

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