1. Consider the amplifier between stations B and C of the temperature measurement system shown in below. [a] Determine the minimum input impedance of the amplifier (in Ω) required to keep the amplifier's voltage measurement loading error, ev, less than 1 mV for the case when the bridge's output impedance equals 30 Ω and it's output voltage equals 0.2 V. [b] Based upon your answer in part [a], if an operational an1plifier were used, would it satisfy the requirement of ev < 1 mV (Hint: Compare the input impedance obtained in part [a] to that of a typical operational amplifier)? Answer yes or no and explain why or why not. [c] What would be the gain, G, required to have the amplifier's output equal to 9 V when T = 72 F?
2. An engineer is tasked with the job of specifying several components of a temperature measurement system. The output voltages from a Type J thermocouple referenced to 0 °C vary linearly from 2.585 to 3.649 mV over the temperature range from 50 to 70 °C. The thermocouple output is to be connected directly to an A/D converter having a range from -5 to +5 V. For both a 12 bit and a 16 bit A/D converter determine [a] the quantization error (in mV), [b] the percentage error at T =50 °C, and [c] the percentage error at T = 70 °C. Now if an amplifier is installed in between the thermocouple and the A/D converter, determine [d] the amplifier's gain to yield a quantization error of 5% or less.
3. Determine the simplified Boolean expression for X in the logic circuit below. Also, complete the timing diagram.
4. Design a passive lowpass filter for a sensor that has a cutoff frequency of 100 Hz. The filter should have a magnitude ratio of at least 0.95 at 50 Hz and not more than 0.01 at 200 Hz. The resistance of the sensor is 10 ohms. You will need to specify the number of even stages and the values for the components. Plot the magnitude ratio of the resulting filter out to 500 Hz