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However, the analysis of a  parallel RLC circuits  can be a little more mathematically difficult than for series RLC circuits so in this tutorial about parallel RLC circuits only pure components are assumed in this tutorial to keep things simple. This time instead of the current being common to the circuit components, the applied voltage is now common to all so we need to find the individual branch currents through each element. The total impedance, Z of a parallel RLC circuit is calculated using the current of the circuit similar to that for a DC parallel circuit, the difference this time is that admittance is used instead of impedance. Consider the parallel RLC circuit below. Parallel RLC Circuit   In the above parallel RLC circuit, we can see that the supply voltage, V S  is common to all three components whilst the supply current I S  consists of three parts. The current flowing through the resistor, I R , the current flowing through the inductor...

Thus far we have seen that the three basic passive components of:  Resistance ,  Inductance , and  Capacitance  have very different phase relationships to each other when connected to a sinusoidal alternating supply. In a pure ohmic resistor the voltage waveforms are “in-phase” with the current. In a pure inductance the voltage waveform “leads” the current by 90 o , giving us the expression of: ELI. In a pure capacitance the voltage waveform “lags” the current by 90 o , giving us the expression of: ICE. This Phase Difference, Φ depends upon the reactive value of the components being used and hopefully by now we know that reactance, (  X  ) is zero if the circuit element is resistive, positive if the circuit element is inductive and negative if it is capacitive thus giving their resulting impedances as: Element Impedance Circuit Element Resistance, (R) Reactance, (X) Impedance, (Z) Resistor R 0 Inductor 0 ωL Capacitor 0 Instead of analysing e...