Unit 19: Electronic Devices and Circuits
(a) Diode circuits
(i) Identify different types of diode and their uses. Write a brief summary for each type. (ii) Construct a schematic diagram of a half-wave rectifier circuit by using circuit simulation software and, using the same software, simulate the operation the half-wave rectifier circuit. Use the Zener diode and series resistor Rz and shunt capacitor Cz specified for you in the table supplied. (iii) Develop the circuit schematic and simulation to a full-wave rectifier with capacitor smoothing and Zener diode voltage regulation. (iv) build a prototype of your final circuit (v) record the output voltage (vi) estimate the voltage ripple for different loads (vii) compare the results from theory, simulation and measurement
(b) Transistor circuits
(i) Identify different types of transistor and their uses. Write a brief summary for each type. (ii) Construct the schematic circuit of a common emitter amplifier in your ECAD circuit simulation program. Use the values (Vcc, C1-C3, R1-R4) specified for you in the table at the end of this brief. Work out the theoretical frequency response of the circuit. (iii) Use the schematic in your circuit simulation program to simulate the behavior of the circuit with a low-voltage (0.1V pp) sinewave input signal of frequency f=1kHz. Adjust the amplitude value of the input voltage to give largest undistorted output voltage. Record the value and record images of the output waveform at this input amplitude value and at a slightly larger input amplitude value causing distortion. (iv) Investigate how the voltage gain changes with frequency between 1kHz and 1MHz. Record your findings including a table of results and a graph. (v) Build a prototype of the simulated circuit and measure the voltage gain for the same frequency range as was used in the simulation. Produce a 4 BTEC Assignment Brief v1.0, edited for clarity by M Harris October 2017 BTEC Internal Assessment QDAM January 2015 table and a graph. (vi) Compare the results from theory, simulation and measurements. Comment on your findings. (c) Operational amplifier circuits (i) Identify the pin-out of an operational amplifier and relate it to the schematic diagram below. Using ECAD, simulate inverting and noninverting amplifier applications of an operational amplifier, noting the effect of resistor values on the voltage gain. (ii) Using ECAD, construct the schematic diagram of a non-inverting amplifier with the voltage gain G1 specified for you in the table of values, using a LM741 opamp IC. (iii) Simulate the circuit and hence plot expected voltage gain at frequencies between 1kHz and 1MHz (iv) Build a prototype of the same circuit and measure the voltage gain over the same range of frequencies (v) Compare the results from theory, simulation and measurements.