X=3 and Y = 102

Question No: 4 (CLO-1) (25 Marks) Instructions Irst = 150uA+XuA RM 2500+XO VAX= XmV+3mV A brain map is based on EEG (electro-encephalogram) signals, i.e. a recording of the electrical voltage fluctuations that are always present when the brain is active. To be able to measure the voltages discharged by the brain, electrodes must be placed on the skull. You are required to design a PMMC based low range AC voltmeter to measure the brain signal voltages by using half-wave precision rectifier. The EEG voltage range is O to VMAX. Your solution should answer the following. 1. Circuit diagram of your designed system. (03) 2. Design calculations. (04) 3. Calibrate and draw the scale at 0,25 liso, 0.50 Irso and 0.75 Irsp to show EEG voltages. (02). 4. Analytically and numerically prove that the scale is linear. (02-02) 5. Suppose the input to the designed voltmeter is Vmax/2. Using calculation, prove that the PMMC will show Vmax/2. (03) 6. Find the overall transfer function of the system. (03) 7. Suppose the Op-Amp used is LM-358, find the input impedance of the designed voltmeter. (02) 8. Assume someone replaces the half-wave precision rectifier with a full-wave precision rectifier. Calculate the PMMC's current if the input EEG signal is (0) Vmax/5 and (ii) Vax/2. (04) Page 3 of 4 Question No: 4 (CLO-1) (25 Marks) Instructions Irst = 150uA+XuA RM 2500+XO VAX= XmV+3mV A brain map is based on EEG (electro-encephalogram) signals, i.e. a recording of the electrical voltage fluctuations that are always present when the brain is active. To be able to measure the voltages discharged by the brain, electrodes must be placed on the skull. You are required to design a PMMC based low range AC voltmeter to measure the brain signal voltages by using half-wave precision rectifier. The EEG voltage range is O to VMAX. Your solution should answer the following. 1. Circuit diagram of your designed system. (03) 2. Design calculations. (04) 3. Calibrate and draw the scale at 0,25 liso, 0.50 Irso and 0.75 Irsp to show EEG voltages. (02). 4. Analytically and numerically prove that the scale is linear. (02-02) 5. Suppose the input to the designed voltmeter is Vmax/2. Using calculation, prove that the PMMC will show Vmax/2. (03) 6. Find the overall transfer function of the system. (03) 7. Suppose the Op-Amp used is LM-358, find the input impedance of the designed voltmeter. (02) 8. Assume someone replaces the half-wave precision rectifier with a full-wave precision rectifier. Calculate the PMMC's current if the input EEG signal is (0) Vmax/5 and (ii) Vax/2. (04) Page 3 of 4