Design of Magnetron power source from three phase supply

Electromagnetic radiations are phenomena that takes the form of self propagating waves in a vacuum or in matter. Microwaves are a part of the electro-magnetic (EM) radiation spectrum, with a frequency range of 300Mhz to 300Ghz. Microwave heating is applied in ceramics, Metallic powder, Food products, Wood, Polymers, Rubber, Textile & Paper. Various sources of microwaves include the Magnetron, Klystron, Travelling-wave tube (TWT) and gyrotron. These devices work in the density modulated mode rather than the current modulated mode. This means that they work on the basis of clumps of electrons flying through them, rather than using a continuous stream. The scope of this project work requires us to focus on such a device namely Magnetron. Microwave wave heating has advantages over the conventional heating due to which it is finding applications in industries for heating. The heart of every microwave oven is a high voltage system whose purpose is to generate “Microwaves”. This high voltage system is called as Magnetron power supply. Three phase supply design for magnetron power source by providing gate firing signal using control scheme to the thyristors can be achieved by using the power scheme design respectively. In power scheme design three identical thyristors are connected in each phase of the three phase line supply and output of the three thyristors are connected to the star connected load. Control scheme design is formed by using the comparators, diode and logic gate. In control scheme, design input is taken from the mains supply and output of the control card which can be used for gate triggering pulses for thyristors. The objective is to design control pulses for the gate triggering signals, and also monitoring various parameters such as voltage, current and total power control for various applications. Using a three phase supply we can achieve high output power to the magnetron power source as compared to the single phase output control in single phase supply with much better ripple characteristics. Thus high power magnetron source for industrial and practical applications is conveniently used.