Department of Mechanical Engineering, Unit Catalogue 2008/09 |
ME10285 Instrumentation, electronics & electrical drives |
| Credits: 6 |
| Level: Certificate |
| Semester: 2 |
| Assessment: CW 100% |
| Requisites: |
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Aims:
* To provide an introduction to measurement, instrumentation and signal processing. * To provide an introduction to electromagnetic actuation systems. Learning Outcomes: After taking this unit the student should be able to: * Match an indicating instrument or data recorder to a given signal source and estimate the accuracy of the indicated output. * Select a suitable transducer type for a particular measurement application. * Describe the shielding and guarding techniques that are necessary to keep extraneous signals in the environment from affecting the signals in a measurement system. * Understand the basic amplification circuits used for instrumentation. * Understand the basic operation of DC motors, stepper motors and three phase induction motors, including speed control and starting methods. * Select appropriate drives for simple applications. (i) understand the characteristics of elementary AC circuits and components. (ii) be able to use strain gauges, LVDTs, accelerometers and capacitance transducers. Skills: Problem solving; numeracy; written communication; working independently. Content: Transducers, strain gauges,: operating principles, characteristics, selection based on application requirements. Measurement of voltage, current and resistance. Use of bridge circuits. Matching of instruments to signal sources. Thevenin's theorem. Explanation of concepts of accuracy, systematic and random errors, noise, linearity and repeatability of measurements. Signal amplification; amplifier types, signal buffers and instrumentation amplifiers.. Brief description of guarding and shielding techniques. A-D conversion, data presentation. Electromagnetic energy conversion - electromagnetic induction, Faraday's and Ampere's laws. Operating characteristics of stepper, DC, brushless and induction motors. Rated motor data and voltage-speed-torque-current-power relationships. Starting and speed control of motors. Power electronic converters and their use for speed control. Elements of AC theory, capacitors and inductors, mutual inductance, transformers. The linearly variable differential transformer (LVDT) application and associated instrumentation. Capacitance transducers. Accelerometers. Amplifier errors and drift. AC characteristics, band-width, signal-to-noise ratio. Electrical noise, AC bridges, advantages of narrow bandwidth amplification and detection. Resonant circuits. |