AC2 Fundamentals Unit 1 – RLC Circuits
Exercise 2 – Parallel RLC Circuits
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to analyze parallel RLC circuits by
using calculations and measurements. You will verify your results with an oscilloscope.
DISCUSSION
- In parallel RLC circuits, components are connected in parallel with the applied voltage
source; each component forms an individual parallel branch. - Consistent with parallel circuit theory, each branch voltage is equal to the applied voltage.
- Ohm’s law and the branch resistance or reactance is used to determine individual branch
currents. - Total circuit current is not the sum of the branch currents. Use the following equation to
calculate total current: IT = sqrt [IR^2 + (IC − IL)^2 ] - Characteristics of the equivalent circuit depend on the dominant reactive component. The
component with the lowest reactance, or highest current, is dominate. - Equivalent capacitance or inductance can be determined from the appropriate reactance
formula once component reactance has been determined by Ohm’s law. - Phase angle is calculated from the following equation: θ = arctan (INET/IR)
- Since the amount of reactance is frequency dependent, circuit values will vary with changes
in the frequency of the applied voltage.