Superposition is a powerful technique that can help you analyze linear circuits with multiple sources. It allows you to simplify complex circuits by considering the effects of each source separately and then adding them up. In this article, you will learn how to apply superposition to solve for currents, voltages, and power in linear circuits.
Superposition is based on the principle that the response of a linear circuit to several sources is equal to the sum of the responses to each source individually. A linear circuit is one that obeys Ohm's law and the principle of proportionality, meaning that the current and voltage are proportional to the source. Superposition only works for linear circuits, not for nonlinear ones that have components like diodes, transistors, or switches.
Superposition is a technique that can be used to streamline analysis in circuits with linear components. For circuits with numerous input sources, this is extremely helpful. Suppressing all but one input or source and then analyzing the resulting simplified circuit allows you to examine a linear circuit with numerous inputs.
To apply superposition, you must first identify all the independent sources in the circuit, such as batteries, generators, or current sources. Then, choose one source to keep active and replace the others with their internal resistance. For an ideal voltage source, this is zero ohms; for an ideal current source, this is infinite ohms. Analyze the circuit using a preferred method, such as Kirchhoff's laws, node voltage, or mesh current. Find the values of the currents, voltages, and power that you are interested in. Repeat these steps for each source in the circuit and add up the results to get the total values of the currents, voltages, and power in the circuit.
Superposition can make circuit analysis easier by reducing the number of equations and variables you need to solve. It can also help you understand how each source contributes to the overall behavior of the circuit. You can use superposition to compare different scenarios or test different hypotheses about the circuit.
Superposition has some limitations that you need to be aware of. First, it only works for linear circuits, not for nonlinear ones. Second, it only applies to independent sources, not to dependent ones that are controlled by other elements. Third, it only gives you the values of the currents, voltages, and power, not the phase angles or impedances. Fourth, it can be tedious and time-consuming if the circuit has many sources or components.
As it is based on sums, it does not give amplitude and phase that do not sum up, but it can give real and imaginary parts that do sum up and can afterwards be turned in amplitude and phase.
To check your results with superposition, you can use a different method of circuit analysis, such as nodal analysis, mesh analysis, or Thevenin's theorem. You can also use a software tool or a simulator to verify your calculations. You can also apply some common sense and logic to see if your results make sense physically and mathematically. For example, you can check if the power is conserved, if the currents and voltages are within the limits of the sources, and if the signs and directions are consistent.