Electrotechnology 1200 Experiment 10 Series RLC Circuits

PROCEDURE B (Determining resonant frequency)B1. MODE to DUAL, SOURCE to INT and PULL INVERT is pushed IN.B2. To the circuit in Figure 10-1, connect the oscilloscope to measure V R PP vs V CD PP .B3. Adjust V CD PP = 6V PP .B4. Switch CH-A and CH-B AC-GND-DC toGND. You will get two horizontal lines.Adjust VERTICAL POSITION to positionthe lines on the X-axis.Switch CH-A and CH-B AC-GND-DC toDC. Your waveforms should be centeredon the X-axis. The waveforms will be outof phase with each other, similar to thedrawing on the right.B5. At resonant frequency f R , X L = X C , and V Swill be in phase with the current I.Therefore if you adjust frequency until V R isin phase with V CD , you can determineresonant frequency.B6. Increase/decrease the frequency toattempt to get waveforms similar but notthe same as the ones shown on the right.As you adjust the frequency, examine bothwaveforms as they cross the X-axis. Makeyour frequency adjustments to bring thesepoints to the same place. Then they will bein phase.As you change frequency, adjust TIME/DIV and CH-A/CH-B VOLTS/DIV to keep 1-3waveforms on the screen.B7. Record the resonant frequency f R [10-3].B8. On pg. 110, calculate the theoretical resonant frequency for these components.ELTK1200 Experiment 10 Rev 5 114