Introduction to Frequency Response

[@Robson-dh3un]

I have no words to express the gratitude that I've been acumulating among these years of NPTEL classes. Your videos helps students to Truly understand the subject of each class. It's increrible. Thank you so much for all NPTEL Team. You're making a better world bringing knowledge in a simply and consistency way. OBS: Your English is one of the best to understand. Thank you for the clear way to speak. Also, when I watch your videos, I'm learning english too. Thanks Namaste.

[@AshwaniYadavIIT]

namaste

[@aritraroygosthipaty3662]

7:37 the R(s) is computed, then C(s)=G(s)*Aw/(s^2 + w^2) i think there has been a mistake and the term is written incorrectly :)

[@anilraghu8687]

37:57 Control systems are usually low pass filters, Gain Margin and phase margins are stability margins.41:46

[@sridharchitta7321]

What is meant by steady-state in a capacitive circuit subject to a sinusoidal voltage input? A sinewave depicts movements in the form of waves. It has a datum, rapid, slowing and steady growth in one direction for a quarter cycle with reference to a datum (a reference), and then slow and faster decay in one direction for the next quarter cycle, and all these elements again in the opposite direction (reversal) of the forward movement for the next half-cycle. It has peaks and valleys. In essence, the sinewave is a perfect embodiment of oscillatory movements like springs and quantities like voltage. It retains its waveshape when added to another sinewave of the same frequency and arbitrary phase and is the only periodic waveform which has this property. Imagine that you and your friend are playing a game of “swing”. When your friend sits on a stationary swing and you begin pushing it, it will take a few hard pushes initially to overcome inertia when the swing moves with a small displacement. You then synchronize your pushes by progressively moving slightly away from the stationary position of the swing, initially, pushing gently, and then pushing harder as you move away from the central stationary position of the swing. The point of pushing the swing is usually at the top of the swing cycle at one end. It takes a while of pushing before you are able to establish a rhythmic swing. The period before the rhythmic swing is established is the “transient”, and the rhythmic swing that is established after the few transient cycles elapse is the “steady-state”. This is analogous to establishing the steady-state in a capacitive circuit subject to a sinusoidal input. The capacitor being initially uncharged, will cause the current during the transient period to assume a value that will be quite different from that at the same voltage angle after steady-state is established. Electrostatics and circuits belong to one science, not two. These are discussed usually separately in textbooks and science and engineering courses. It is not possible to discuss the circuit processes which produce a sinusoidal current when a sinusoidal voltage is applied to a capacitor….the changing rates of change of the applied voltage ….the surface charge set up changing at every instant….the applied field changing in the wires ….and the current at each and every instant in time. Watch the two videos listed below to learn about current and the conduction process and surface charges (using a unified approach to electrostatics and circuits at a fundamental level). 1. kzbin.info/www/bejne/iHbWiJeabJukrsU 2. kzbin.info/www/bejne/bnO0fpKurJeFnNE The last frame of video #1 lists textbook 4 which discusses the sinusoidal steady-state in capacitors and inductors with the help of sequential diagrams and animated power-point presentations of the varying field components in the circuit elements in more detail.

[@benjemenpallala9870]

Thanks a lot sir. Good foundation lecture for frequency response analysis.

[@abhinavgupta7930]

Truly commendable work sir! Can u please share lecture slides all the chapters after root locus?

[@rohitanand5403]

conceptual and to the point . :)

[@saptarshimandal8545]

at 14.30 min , the

[@PritamPrasadSah28]

sir please immediately show your pointer in a big point tip of pen show i can get to know where u are pointing and where u are taking this is changing with time or else

[@chandrashekhardasari1345]

Yes

[@hpvide]

Why M = 1/√2