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QUESTIONS 4. EXPERIMENT 4: ANALYSIS BY «NODE-VOLTAGE METHOD». OBJECTIVES. NODE-VOLTAGE EQUATIONS Number of equations Number of unknowns When, additional unknowns? Solution? NODE-VOLTAGES/ELEMENT VOLTAGES RELATIONS. NODE VOLTAGE METHOD.
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QUESTIONS 4 EXPERIMENT 4: ANALYSIS BY «NODE-VOLTAGE METHOD» Ertuğrul Eriş
OBJECTIVES • NODE-VOLTAGE EQUATIONS • Number of equations • Number of unknowns • When, additional unknowns? Solution? • NODE-VOLTAGES/ELEMENT VOLTAGES RELATIONS Ertuğrul Eriş
NODE VOLTAGE METHOD Current flow references random, but voltage plarity references are not!!Why? Independent KCL equations - Va + Node voltage equations: Unknowns: Is, v1, v2, v3 3 equations 1 supplementary equation: V1=10V 4 unknowns, 4 equations Ertuğrul Eriş
NODE VOLTAGE METHOD Current flow references random, but voltage plarity references are not!!Why? Negative currents could be changed to positive if the references are changed to opposite Ertuğrul Eriş
NODE VOLTAGE METHOD Tranffering the calculated results to realistic ones by rearranging the chosen current and voltage references. - Vc + - Va + When changed the current reference of a resistor then voltage reference should also be changed, This is not true for independent voltage source, why? Ertuğrul Eriş
QUESTIONS • What is Kirchoff current Law (KCL)? • What is the relation between element voltages and node voltages? Does this relation require any voltage or current reference? Write down Va and Vd resistors voltages in terms of node voltages. • Write down Kirchoff current law (KCL) for all the nodes. Does this require any reference direction rule? Why, explain? • Write down Kirchoff voltage law (KVL) for all the meshes. Does this require any reference direction rule? Why, explain? • How many equations you need to solve for the above circuit? What are they? • How many unknowns are there? What are they? • Can we figure out all the unknowns of the circuit in term of node voltages? How? • When do we need "passive sign convention"? Ertuğrul Eriş
PROBABLE SOURCES OF ERRORS IN CALCULATIONS • Number of digits after decimal point Ertuğrul Eriş