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J 1. J be. J ki. +. A. -. J v = ß J o. ß. Class 19. Purpose of feedback Principle of feedback. oscillation with const. amplitude. narrower pos. f.b. oscillation with growing amplitude. H. -1. 0. negative feedback. positive feedback. Class 19. The cases of feedback. Class 19.
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J1 Jbe Jki + A - Jv=ßJo ß Class 19 • Purpose of feedback • Principle of feedback
oscillation with const. amplitude narrower pos. f.b. oscillation with growing amplitude H -1 0 negative feedback positive feedback Class 19 • The cases of feedback
Class 19 • Why do we use almost always negative feedback? • Interpreting the negative and positive feedback rigorousely • The Nyquist diagram of the loop-gain • Structural and conditional stability • The notion of stability margin • Determining the phase margin by means of Bodeplot • The special case of the 45 phase margin
Auüu1 Rki Rbe u1 Rg uki Rt ug ube ßuuki Class 19 • The four basic feedback arrangements of asymmetrical amplifiers • The ideal feedback circuit • The series voltage feedback (S-V)
YA ocv1 io Rin Ro v1 Rg RL vin vg Zßio Class 19 • The series current feedback (S-C)
ZA sci1 Ro Rin i1 iin ig Rg vo Yßvo Class 19 • The parallel voltage feedback
Ai sci1 Ro io Rin i1 iin RL ig Rg ßiio Class 19 • The parallel current feedback (P-C)
Class 19 • The S-V feedback detailed: • - Transfer parameters • - Input resistance • - Output resistance • In case of Rg = 0 • Application of the results for other types of feedback