Effect of feedback on dynamic response and bandwidth, Electrical Engineering

Assignment Help:

Q. Effect of feedback on dynamic response and bandwidth?

Let us consider the block-diagram representation of the open-loop system shown in Figure 16.2.5(a), whose direct transfer function is given by

1499_Effect of feedback on dynamic response and bandwidth.png

corresponding to which, the transient solution of the system is of the form given by

c(t) = Ae-t/τ

The transient in this system is seen to decay in accordance with a time constant of τ seconds. By placing a feedback path H around the direct transfer function, as shown in Figure (b), the closed-loop transfer function is then

2190_Effect of feedback on dynamic response and bandwidth1.jpg

2203_Effect of feedback on dynamic response and bandwidth2.png

and the corresponding transient solution of the closed-loop system is of the form

cf (t) = Afe-[(1+HK)/τ ]t

where cf(t) represents the transient response of the output variable with feedback. Comparing Equations, it is clear that the time constant with feedback is smaller by the factor 1/(1 + HK), and hence the transient decays faster.

By treating the differential operator p as the sinusoidal frequency variable jω, i.e., p = jω = j(1/τ ), it follows from Equation that the bandwidth of the open-loop system spreads over a range fromzero to a frequency of 1/τ rad/s. On the other hand, for the system with feedback, Equation reveals that the bandwidth spreads from zero to (1 + HK)/τ rad/s, showing that the bandwidth has been augmented by increasing the upper frequency limit by 1 + KH.


Related Discussions:- Effect of feedback on dynamic response and bandwidth

Conductors for lines, Conductors for Lines The sizing of conductor mus...

Conductors for Lines The sizing of conductor must depend upon the load it is expected to serve and other factors, such as capacity required in future. Or else conductors/cable

Design a multiplexer and anomalous signals, 1. The size of the multiplexer ...

1. The size of the multiplexer used to implement a truth table can be cut in half (e.g. 4 inputs instead of 8) if one of the variables is used as an input instead of being connecte

Draw a schematic diagram of transformer connections, Q. Three single-phase,...

Q. Three single-phase, 10-kVA, 2400/120-V, 60- Hz transformers are connected to form a three- phase, 4160/208-V transformer bank. Each of the single-phase transformers has an equiv

Mobile and wirelss communicatio, In a CDMA system, the signal is spr...

In a CDMA system, the signal is spread over a large bandwidth by multiplying the transmitted symbol by a sequence of short pulses, also called chips. The

Designated consumers - features of energy conservation, Designated Consumer...

Designated Consumers - Features of Energy Conservation The Act gives the list of designated consumers, which involves the energy intensive industries, Railways, Port Trust, Tr

Explain what happen as the frequency increases, Question: (a) A typica...

Question: (a) A typical RF filter is made up of sections using circuit components. One example of a section is the Inductor-Capacitor (L-C) section. State two other types of

The a.c/d.c. generator - electromagnetic torque, Note, the armature curren...

Note, the armature current is produced in pulses as the armature rotates under the poles, so the torque also pulsates. This can give rise to extra wear on bearings and the engin

Develop a two-dimensional addressing system, Q. Suppose a ROM holds a total...

Q. Suppose a ROM holds a total of 8192 bits. (a) How many bits long would the individual addresses have to be? (b) If the bits are organized into 8-bit memory words or bytes,

Define sampling frequency, Define Sampling Frequency? Since real analog...

Define Sampling Frequency? Since real analog signals consist of several frequencies, spectrum of the input signals should be limited to make sure that no signal energy exists a

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