Electricity and Magnetism > AC Circuits DCS# 5L20.20 v.2

RLC SERIES CIRCUIT WITH 4-CHANNEL SCOPE



APPARATUS
function generator 107-01-A
500 - 6-8 ohm audio transformer 214-01-D
60 mH inductor 214-01-D
1 uF capacitor 101-09-G4
decade resistor 214-01-A
1:1 isolation transformer
202-08-B2
4-channel oscilloscope with camera 202-08-B-5


DESCRIPTION
All four signals - Vin, VR, VL and VC - can be displayed simultaneously. 

This setup can be used to show:
    resonance in a series RLC circuit.
    the broadening of the resonance peak with increasing R.
    phase relations in an RLC circuit.
    the relative sizes of XC and XL at frequencies above and below resonance.
    phase relations in RC and RL circuits:  short the inductor or capacitor with a wire.
    transient oscillations in an RLC circuit:  use the Pasco function generator/amplifier square wave output.
    RC and RL time constants:  short inductor or capacitor and use square wave mode of function generator.

NOTES

f = [2π(LC)]-1 = 650 Hz

Start with R = 100 ohms.
Note that VR does not have the same amplitude as Vin at resonance because of the resistance (6 ohms) of the inductor.

Adjust the camera aperture so that the colors of the traces are apparent in the projected image.

Color code:

    Vin (Ch1) is yellow,
    VR (Ch1-Ch2) is red,
    VL (Ch3) is purple,
    VC (Ch4) is green.