Answer Happy

Low Pass and High Pass Filters Objectives: 1. Become familiar with the characteristics of low pass and high pass filters. 2. Plot the frequency response of low pass and high pass filters. 3. Plot the dB loss of low pass and high pass filters. Equipment: 1. Resistors 10K9, 6200 2. Inductors 33mH 3. Capacitors 0.01F 4. Dual Channel oscilloscope 5. Audio-oscillator 6. Digital Multimeter (DMM) Run IRC Low Pass Filter 1. Construct the network of Figure 10-1. Oscillator Oscilloscopo R 10K Ohms Output С -0.01 UF CH1 CH2 Figure 10-1 2. Vary the input frequency from 200Hz to 100 KHz as shown in Table 10-1 and measure the Vo while maintaining the input voltage at 4Vye for each value of frequency 3. Compute the gain Ay for each frequency indicated in Table 10.1 4. Compute the dB loss for each frequency indicated in Table 10.1

vi VO A-Vovi dB Frequency (Hz) 200 500 1000 12000 1400 1500 1600 1700 1800 2000 3000 4000 5000 7500 10000 15000 20000 100000 Table 10.1 Run II RI High Pass Filter 1. Construct the network of Figure 10-2 Oscillator Oscilloscope R 620 Ohms Output L 33m11 CH1 CH 2 Figure 10-2 2. Vary the input frequency from 100Hz to 100 KHz as shown in Table 9-1 and measure the V while maintaining the input voltage at 4Vpp for each value of frequency

3. Compute the gain Ay for each frequency indicated in Table 10.2. 4. Compute the dB loss for ench frequency indicated in Table 10.2. V VOPP A =V/V dB Frequency (Hz) 100 200 500 1000 1500 2000 2500 2800 3000 3200 3500 4000 5000 7500 10000 15000 20000 100000 Table 10.2 Required Results 1. Plot dB loss vs. frequency for Run I using EXCEL spreadsheet. Set the horizontal axis as frequency with logarithmic scale from 100 Hz to 100KHz. Set the vertical axis as dB loss with linear scale from zero to -40 dB. The plot should cover a full letter size page with its length as horizontal axis and its width as vertical axis. 2. Plot dB loss vs. frequency for Run II using EXCEL spreadsheet on the same page as above. 3. Calculate cutoff frequency for Run 1. 4. From the graph of step 1 above find the frequency that has loss of 6dB. 5. Compare the frequency from the steps 3 and 4 above. 6. Calculate cutoff frequency for Run II. 7. From the graph of step 2 above find the frequency that has loss of 6dB. 8. Compare the frequency from the steps 6 and 7 above.