Prévia do material em texto
Problem 9.14PP Derive the describing function for the ideal contactor controller shown in Fig. Is it frequency dependent? Would it be frequency dependent if it had a time delay or hysteresis? Graphically sketch the time histories of the output for several amplitudes of the input and determine the describing function values for those inputs. Figure Contactor for Problem Step-by-step solution Sketch the given figure. Step 1 of 7 Step 2 of 7 ^ The standard equation is u ( t) - asin(dv) and sin Qat + Step 3 of 7 This is an odd nonlinearity so that all the cosine terms are zeroes and the DF is real — J|j*^[j4sin(atf)-l]sin(aif) d(ait) Step 4 of 7 ATOn further simplification we get 2̂ = — cos(