# Parallel resonance analyzed with Ti-84 Plus (CE)

## Explanation of the parallel resonance program for the Ti84

Parallel resonance circuits are used in notch filters, radio receivers, transmitters, power factor correctors, making them a useful topic for electrical engineers.

The program plots all currents and voltages.

Phase and amplitude resonance can be calculated and as all functions are saved in the Y-editor, more post-processing is possible.

In this case a circuit with Rs=50 Ohm, Ls=3.8mH, RL= 0.5 Ω and C=0.1uF is analyzed. Total current and phase as function of frequency are shown. As you see, the frequency at minimum current= 8164.47 Hz which is equal to the analytically calculated frequency =1/(2π√LC) since the resistance of the coil is very small.

Find out for yourself that the resonance frequency shifts to 7974 Hz for RL=100 Ω instead of 0.5 Ω.

### The Electric circuit of Parallel resonance

Plots as function of frequency (Hz) are shown. On the left, the source current. The LC circuit behaves like a notch filter and blocks frequencies in the area of 8164 Hz. On the right, three currents are plotted. Blue= the total current, Green= the capacitor current, Red= the coil current.

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