Question

# The voltage signals vA and ve from two microphones need to be amplifiedindependently and then mixed(summed)together into a single output vout =(AvABve).where A and B are amplification terms that can be

adjusted between 0and 100 using separate potentiometers.a)Draw a circuit schematic using ideal op-amps that performs this operation.[6 marks]b)Explain how the circuit works and design the values of components toperform the required operation.[6 marks]c)Assuming a rail voltage for all the op-amps of +-5V,what is the maximumoutput amplitude from each microphone that avoids saturation?[3 marks]dThe signal obtained from a)needs to be filtered to attenuate high frequencynoise.Which of the following circuits using ideal op-amps is the mostappropriate for this function and why?RMInputInputInputROutputOutputOutputCIRCUIT 1CIRCUIT 2CIRCUIT 3[3 marks]e)Choose the values for R and C in the circuit you have selected from (d)toobtain a cut-off frequency of 1X.Y kHz,where X and Y are the last two digitsof your student number.For example,if your student number is 1234567,the cut-off frequency is16.7kHz.

Fig: 1