NEWS AND INFORMATION

Both are 3-element networks that contain two reactive components making them a second-order circuit, both are influenced by variations in the supply frequency and both have a frequency point where their two reactive components cancel each other out influencing the characteristics of the circuit. Both circuits have a resonant frequency point. The difference this time however, is that a parallel resonance circuit is influenced by the currents flowing through each parallel branch within the parallel LC tank circuit. A  tank circuit  is a parallel combination of L and C that is used in filter networks to either select or reject AC frequencies. Consider the parallel RLC circuit below. Parallel RLC Circuit   Let us define what we already know about parallel RLC circuits. A parallel circuit containing a resistance,  R , an inductance,  L  and a capacitance,  C  will produce a  parallel resonance  (also called anti-resonance) circuit when the resultant current through the paral

We have also seen in our tutorial about series RLC circuits that two or more sinusoidal signals can be combined using phasors providing that they have the same frequency supply. But what would happen to the characteristics of the circuit if a supply voltage of fixed amplitude but of different frequencies was applied to the circuit. Also what would the circuits “frequency response” behaviour be upon the two reactive components due to this varying frequency. In a series RLC circuit there becomes a frequency point were the inductive reactance of the inductor becomes equal in value to the capacitive reactance of the capacitor. In other words,  X L  = X C . The point at which this occurs is called the  Resonant Frequency  point, (  ƒ r  ) of the circuit, and as we are analysing a series RLC circuit this resonance frequency produces a  Series Resonance . Series Resonance  circuits are one of the most important circuits used electrical and electronic circuits. They can be found in var