PC CONTROLLED FUNCTION GENERATOR USING DIRECT DIGITAL SYNTHESIS (DDS) TECHNOLOGY FOR ELECTRICAL CAPACITANCE TOMOGRAPHY

A function generator is widely used for experimental work and testing to generatevarious types of waveform (sine, square, triangle, etc) with a particular frequency bandwidth.One of its applications is in generating waveform for the ECT (Electrical CapacitanceTomography) system. ECT is used to retrieve the details of material in a flow system. Aneconomical PC Controlled Function Generator was designed for the use of waveformgenerating in ECT. For the ECT system, high accuracy and frequency waveforms are needed.Three basic waveforms are required; the sine wave, square wave, and triangular wave. Theobjective is to build a function generator which is capable of generating high accuracywaveforms with acceptable distortion and stability. An interfacing system between a PC andthe function generator was also selected and developed with the purpose of producing accurateamplitude and frequency of the waveforms. This interfacing allows remote control to thefunction generator for a wider usage.