Thesis
Design of a new transformer isolated analog acquisition system having greatly reduced transformer size and weight while achieving high accuracy
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/101383
Abstract
The design of a new transformer isolated analog acquisition system greatly reduces the size, weight, and cost of the isolation transformer. The concept of pulsing the isolated analog signal only for the portion of time needed for A-D conversion is developed. High accuracy of the isolated analog signal is achieved using an operational amplifier with a feedback winding from the isolation transformer. The additional use of the isolation transformer for an isolated switched mode power supply is also developed. The implementation of the isolation transformer using a small E-E ferrite core and printed circuit windings is described. A SPICE (Simulation Program with Integrated Circuit Emphasis) model is developed for the E-E ferrite core, printed circuit board winding transformer used in the Isolated Analog Selector circuit. SPICE models for the part-to-part and temperature extreme variations identify the design constraints of the isolation transformer. SPICE models of the electronic control circuitry used in the new isolated analog acquisition system help identify, measure, and improve the stability and accuracy of the design An FEA (Finite Element Analysis) tool is used to determine the accuracy of the isolation transformer of the isolated analog acquisition system. The FEA tool assists in improving the isolation transformer's coupling accuracy by identifying the optimum placement of traces for the printed circuit board windings. The test results of a prototype circuit incorporated into an existing digital protective relay product are presented.
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Details
- Title
- Design of a new transformer isolated analog acquisition system having greatly reduced transformer size and weight while achieving high accuracy
- Creators
- Timothy Michael Minteer
- Contributors
- Robert G. Olsen (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Identifiers
- 99900525158301842
- Language
- English
- Resource Type
- Thesis