The following thesis describes the design and construction of a microcontroller based user interface for use in industrial induction heaters. In the induction heating process, it is vital to have good control over the power electronics in the generator. Through the user interface the user has control over all the relevant parameters that control the oscillations in the work head. The user has also all the relevant data on display such as the DC/DC output voltage, the current being drawn from the electrical grid, the current being drawn on the output of the DC/DC converter, alternating current from the H-bridge and phase locked loop status.
The thesis consists of multiple sections. The first section describes the process of induction heating, its usage in industry, fundamentals of resonant frequency and how it is measured. The following section describes the current regulation loop, suggested improvements on the regulation loop and the design goals for the new user interface. The fourth part describes the process of component selection and different parts of the circuit. There is also described the process of drawing the schematic and the design and manufacture of the printed circuit board. Next part contains a general description of the whole program, with a more in depth description of a couple more interesting parts of the program. In the last section, the testing and possible improvements are described.
The user interface meets all the design criteria and has proven sufficient for further development of the new control system. The biggest problems, that have been encountered, have to do with the quality and the reliability of the display. The interface has great upgrade capability and can easily be modified and fitted with extra functionality, which has proven immensely useful during the development of the new regulation loop.