Download EECS 145L Midterm 2: Electronic Transducer Lab and more Exams Electronics in PDF only on Docsity!
UNIVERSITY OF CALIFORNIA
Electrical Engineering and Computer Sciences EECS 145L Electronic Transducer Lab MIDTERM #2 (100 points maximum) (closed book, equation sheet provided, calculators OK) (You will not receive full credit if you do not show your work)
PROBLEM 1 (20 points)
In 50 words or less, describe the essential differences between the following two items:
1a (10 points) [Sensor] and [Actuator]
1b (10 points) [Thermocouple] and [Thermistor]
PROBLEM 2 (16 points)
2a (8 points) What are the technical requirements of the ground fault interrupter circuit? (Hint: the maximum safe current through the human body is 5 mA.)
2b (8 points) Describe how the ground fault interrupter circuit functions to meet those requirements.
PROBLEM 4 (48 points)
Design a system that converts sound into light for transmission down an optical fiber and then converts the optical signal back into sound.
Assume the following
1 You have a microphone that produces a maximum differential signal of 100 mV p-p (peak-to- peak) at the maximum sound intensity that you need to consider.
- The microphone wires have 60 Hz electromagnetic pickup of 10 mV common mode (assume perfect common mode rejection and zero differential 60 Hz pickup).
- You have an light emitting diode (on one end of the optical fiber) that should produce 100 mA p-p when the microphone signal is at maximum.
- You have a photodiode (on the other end of the optical fiber) that produces 1 mA p-p when the light emitting diode is producing its maximum signal (100 mA p-p input).
- The loudspeaker should be driven at 10 V p-p when the microphone signal is at maximum. The speaker has an input impedance of 10 Ω.
- Each element in the system should be operated in a linear mode (output proportional to input).
In your design you should provide enough detail so that a skilled technician could be able to build it and understand how it works. Include all necessary components and label all signals with their maximum (p-p) amplitude. You may use any circuit components used in the laboratory exercises or discussed in lecture, but keep it simple.
