الفهرس 
ContentsOnly 14 pages are availabe for public view
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Abstract
thesis is concerned with the use of chopper circuits in controlling the speed of excited motors. The system consists of a dc its loading unit, fed from the output of a chopper work is initiated to show the advantages and of chopper circuits and the present state of the approaches for the analysis of chopper fed dc presented.
circuits which use thyristors are discussed with their associated firing and commutating This part explains why transistors are more thyristors in low power chopper circuits. represents three chopper circuits:
circuit is the most primitive chopper circuit only one transistor. It provides the operation motor only in one direction of rotation, and the is restricted on the first quadrant of the 10 diagram.
circuit is the bridge chopper circuit,it has drive the motor on both directions of In each dirction two transistors, one on each conducting at the same time,while the other two the operation is restricted on the fourth quadrants,with motor current always but may be continuous or discontinuous according