Overview of experiments and projects

Transcription

1 Overview of experiments and projects

2 Pathways: Experiments Experiment EE ECE Media Eng D: Op Amps 1 1 F: Digital Communications S: Pulses and Bandwidth 1 J: Transformers 1 K: Wave Propagation 1 Software Project (Linux) 4 Loudspeaker Response 1 Audio-Visual Production Project 5 Acoustic Noise Measurement 1 Room Impulse Response 1 FM Receiver Project 5 5

3 Location of Labs In the main Elec Eng UG laboratories or the Tels Lab Op-Amps Digital Communications Pulses and Bandwidth Transformers Wave Propagation Software Project FM Receiver Project In the Media Lab Loudspeaker Response Audio-Visual Production Project Acoustic Noise Measurement Measurement and processing of room impulse responses

4 Lab Web Page Web Page Online lab manual Videos about experiments Timetables, group lists etc. Experiments not in the lab manual, only on web Software Project Loudspeaker Response Audio-Visual Production Project Acoustic Noise Measurement

5 Remote Access to Web Page Access to some parts only via university IP address Copyright issues with some material Use when off-campus

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8 FM Receiver Project Objective Create a prototype FM receiver Basic design PIC controls FM Receiver Chip LCD Display Programme PIC in C using MPLAB Work in groups of 3-4

9 FM Receiver: System Overview Development Platform Debugger Channel Change Push Buttons Serial Converter Microcontroller PIC18LF6490 Frequency Readout LCD Display Antenna Tuner / Demodulator Audio Amplifier

10 D1: Operational Amplifier Objectives/aims Investigate non-ideal properties of op-amps Bias current, offset voltages, slew rate, etc. Gain vs. frequency plots Integrators Preparation tips Study Clayton book in particular Look at data sheet for 741 op-amp Try some example calculations using data sheet values, particularly for part 1 Sketch out the circuits required Predict the results, sketch some example graphs Briefly describe necessary experiment steps instructions do not say absolutely everything

11 Experiment Part 1 Find offset voltage, bias currents using circuits like this one Too small to measure directly How? Try putting values from the data sheet into equations (a),(b),(c) Are some values much smaller than others?

12 Experiment Part 1 Measure gain and frequency response How do different Rf values change the response? How to use log-linear graph paper? How to find cut-off frequency?

13 J: Transformers Objectives/aims Learn The construction of low frequency transformers The relationship between magnetic flux, induced EMF and magnetising current The idea of a magnetic circuit The limitations of iron as a magnetic material One of the simplest equivalent circuits for the transformer Sources of loss in a transformer and the effect of frequency on the relative magnitude of these losses Preparation tips Basic transformer principles try Wikipedia? Books are usually better Read material in lab manual Answer questions in lab manual Predict results

14 Transformers: Method Goal Design secondary winding to give exactly 6A in the 0.11Ω load resistor, with the primary voltage adjusted to exactly 12V First Analysis of transformer See video for more details

15 Transformers Video

16 K: Wave Propagation Aims/objectives Study standing waves in Coaxial cable Waveguide Free space Learn about standing wave and transmission theory Preparation Read suggested reading material Answer questions in lab manual

17 Part b: Waveguide Standing wave detector Load Gunn Diode Source Cavity Wave Meter Variable Attenuator Crystal Detector* Crystal Detector To CRO To CRO

18 S: Pulse And Wide Bandwidth Measurements Aims/objectives Demonstrate loading and mis-match problems associated with oscilloscope leads and probes Show the effect of parasitic resonances in decoupling circuits. Observe the variation in "ground" potential at different points on a PCB Preparation Answer questions May be able to predict some results based on theory

19 F: Digital Communications Aims/objectives Familiarise you with some of the concepts and problems involved in transmitting digital data from a remote transmitter to a receiver Familiarisation Different pulse shapes, effects of filtering pulse Covers material not in telecoms lectures Preparation Lab manual specifies exercises Equipment manual contains exercise details Available online via web page, also in labs Preparation as specified in lab manual

20 Group Software Design Project: Online publications database Aims/objectives Implement a publications database Record and display summary of university conference and journal publications Work in teams (3-5 people) Learn about MySQL, Perl, CGI Final technical report Preparation Read web page, follow links MySQL reading Look for example publication databases on the web

21 S4: Loudspeaker Frequency Response Objectives/aims Determine the frequency response of a loudspeaker use recordings of the voltage and current, and sound pressure using a measurement microphone Observe the resonant properties of the loudspeaker enclosure, and account for these in the loudspeaker response measurements Preparation Read experiment instructions Can you predict results? How does the Matlab script work?

22 S5: Audio Distortion Measurements Aims/objectives To characterise an audio processing algorithm using various audio distortion measurements To gain familiarity with frequency representations of audio Preparation Read experiment and required reading Study matlab scripts Predict results

23 Summary Experiments likely to start in week 1 Keep checking your , lab web page for updates Printed manual provided in week 1 All material will be placed online during Xmas holidays All labs located in main L2 labs Apart from Media Eng experiments Lab groups should be same as previous semester Check web page for updates