Designing a Magnetic Amplifier Used For DC Motor Speed Control

Abstract

Nowadays magnetic components play an important role being considered as main elements in manufacturing semiconductors, microprocessors, transistors, converters, transformers, magnetic amplifiers and in many other applications which become more prevalent in our daily life. The design of magnetic components is very complicated due to several aspects. Many issues must be taken into consideration by design engineers to maximize the efficiency and minimize the losses. The designers must be aware of choosing a core material which is suitable for the operating mode whether it is a low frequency mode or a high frequency mode. Also the core shape and the effect of air gap must be adequate to the power rating of the load application. This paper gives a brief summary of the most famous different methodologies for designing the magnetic core. It also lists the main features for selecting the magnetic core materials, magnetic shape and the air gap applications. Then an analytical formulation is presented to design a magnetic amplifier used in DC motor speed control which is categorized as a low frequency application. Finally the winding losses as well as core losses are calculated to check the temperature rise of the core and its adaptability to the application.