Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: In the past few years, a need for consulting on microwave heating has surfaced. Since most
specialised microwave components are imported, this adds a hefty price tag in developing the
infrastructure for such consultation. This thesis looks at the design oflow cost alternatives for
use in the laboratory.
A microwave source output with variable output power is often required for consultation. The
calculation of product costs may also be simplified if the available microwave power is
constant despite load changes.
The magnetron as a load was first investigated and a high voltage SMPS was then designed to
control the output of the magnetron according to operator / consulting requirements. To
ensure adequate feedback of system output and load matching, a dual directional coupler has
been designed and implemented.
Since the amount of microwave power required has a direct impact on the initial capital
expenditure, costs need to be kept low by optimising the system. An impedance matching
unit was designed to match the magnetron with the load, saving energy and reducing system
costs. Through automation, the system will strive for the optimum load condition without
operator intervention. / AFRIKAANSE OPSOMMING: Die afgelope paar jaar het 'n behoefte ontstaan aan konsultasiewerk op die gebied van
mikrogolfverhitting. Aangesien gespesialiseerde komponente meestal ingevoer word,
bemoeilik die koste daarvan die ontwikkeling van die nodige infrastruktuur vir konsultasie.
Hierdie tesis kyk na die ontwerp van goedkoper alternatiewe vir laboratoriumgebruik.
'n Mikrogolf bron met 'n verstelbare kraglewering is dikwels nodig tydens konsultasiewerk.
Produk kosteberekinge kan ook vereenvoudig word indien die mikrogolf kraglewering
konstant bly, ongeag produk veranderinge.
Die magnetron as GS las is eers ondersoek waarna 'n hoogspanning geskakeldekragbron
ontwerp is om die uittree van die magnetron te verstel volgens operateur- /
konsultasievereistes. 'n Dubbele direksionele koppelaar is ontwerp en by die laboratorium
opstelling gevoeg om voldoende terugvoer van die kraglewering en impedansie aanpassing te
verseker.
Die hoeveelheid mikrogolf drywing wat benodig word, het 'n direkte impak op die
aanvanklike kapitale uitgawe vir die stelsel. 'n Optimale stelsel is dus noodsaaklik om kostes
te bespaar. 'n Impedansie-aanpassingsnetwerk is ontwerp om die magnetron en las by mekaar
aan te pas om sodoende energie en kostes te bespaar. Deur outomatisering streef die stelsel na
optimale werkverrigting sonder enige ingryping deur die operateur.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52626 |
| Date | 12 1900 |
| Creators | Gerber, J. W. (Johann Wessel) |
| Contributors | De Swardt, J. B., Stellenbosch University. Faculty of Engineering. Dept. of Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 92 p. : ill. |
| Rights | Stellenbosch University |
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