Objectives: After performing this experiment, you should be able to: 1. Construct and test the Wein-Bridge Oscillator for various values of R and C combinations. 2. Calculate and measure the frequency of oscillations. Submission Requirements: Submit the Multisim.ms14 files along with your Experiment 5 lab document. Components: 1. Op-Amp (1) 741C 2. Capacitors (2) 1µF, (2) 1nF, (2) 10nF, (2) 100nF 3. Resistors (2) 1.5k№, (3) 10k№, (1) 22kº Procedure: 1. Experiment 5: Wien-Bridge Oscillator For the circuit shown in Figure 1 below, calculate the frequency of oscillations using the formula below for the R, C values shown in table 1 below. Record the results in table 1 under calculated frequency. R 10 ΚΩ 1.5 ΚΩ C 1 nF 10 nF 1.5 ΚΩ 100 nF Vin(pp) @ pin 3 fr = Vout(pp) @ pin 6 1 2πRC Gain Av Calculated Freq. (fr) Table 1: Calculated and measured values Measured Freq. (fr) 2. Construct the circuit shown in Figure 1 in MultiSim. (Note: First build the op-amp amplifier circuit, then the output of the amplifier feeding input to the lead-lag circuit. Output of the lead-lag circuit is feeding to the input of the amplifier at pin 3.) Lead-Lag Circuit 2014 22:50 1179 2.... 251 252 SONY C4 1nF ..... R3 10kQ C1 HE 1nF Colchon 4₁: R2 www 10kQ R1 10kQ VCC (pin 51) 15V -15:0V 2 Figure 1: Wein-Bridge Oscillator Place Your Schematic Here U1. Go To VEE (pin 52) 1.00k-Pot LM741CN C2 DE 1μF MASA 26 ....... C3 DE 1μF 728 37 2000 2001 BER S 3. 4. 5. 6. 7. 8. Connect the output (pin 6) of the circuit to the Tektronix TDS2024 oscilloscope. Use the scope MEASURE settings to obtain the Vpp and Frequency measurements. Tune the 100k potentiometer so that you see a clear sine wave without any clipping. (Note: Depending upon where you are on the pot, you may need to turn the wiper a lot to see the signal. Change the potentiometer property settings so you can adjust by 1%) Measure the output voltage of the amplifier at pin 6 using the oscilloscope and record the results in Table 1 above under Vout(pp). Measure the frequency of the output sinewave and record the result in Table 1 above under measured frequency. Measure the input voltage of the amplifier at pin 3 using oscilloscope and record the results in Table 1 above under Vin(pp). Calculate the gain of the amplifier using the measured voltage and record the results in Table 1 above under the measured gain (Av). Av = Vout/Vin 3 FOUR CHANNEL Tektronix TDS 2024 DIGITAL STORAGE OSCILLOSCOPE Tek and has CH1 1V AA F Acq Complete M Pos: -20us CH2 5V M 20us CH1/ OV 12.7kHz Sample Scope Display R=10kQ, C=1nF 200 MHz 205/% MEASURE CH1 Pk-Pk 3.28V *********End of the experiment ********* 4 CH2 Pk-Pk 10.1V CH2 Freq 12.7kHz CH2 None Place Your Scope Displays (for each configuration here) Label them appropriately CH1 None 10. Replace the lead-lag circuit R and C values as listed in Table 1 above, and repeat steps through 9.