The diploma thesis describes the development of an excitation system for coil sensor, which is a part of an electronics in a final inspection device for a given home appliance. The main goal of the diploma thesis was to find an improved excitation system and resolve issues that occur in the existing inspection device.
In the introduction the issues and an example of an end product for which the excitation system is being developed is presented. Further, the theoretical background that is needed when designing a new excitation system is also presented. Next the original system, the required specifications and the calculations for optimal development are described. Finally, the guidelines that were took into an account in the fabrication are described.
The coils that are available on the market are presented in more detail, as well as the individual functionality tests that have been carried out. The tests were performed to verify how different types of coils and their coupling affects the induced voltage in the windings of the coil sensor. As the results did not meet the expectations and the mail goal of the diploma thesis, a secondary goal was set – to find suitable replacements for the coils to reach the main goal - to improve the excitation system.
The results lead to the creation of a custom excitation component. A standard ferrite core was mechanically adapted: We fabricated a custom coil and tested its properties. The results showed that exciting a sensor coil with this type of component is much more stable and reliable than a standard coil.
In the conclusion, a new test programme is presented which is based on the new excitation component. The LabVIEW software and the cRIO system were used.