Work and Study @KELLER

For the past three years, I have been studying towards the Advanced Federal Diploma of Higher Education in Electrical Engineering at the Swiss Technical College TEKO. KELLER gave me the opportunity to work and study on a part-time basis.

The last five months of my studies were reserved solely for the diploma thesis. For this, I left my workplace in Quality Assurance for one to two days a week. During this time, I was able to work on my thesis in the Development Department. Combining my further education with work in this way was ideal for me. 

Together with Christian Gysel, electronics and software developer, we worked out the appropriate thesis assignment. My goal for the assignment was that it be useful for KELLER, but also to meet all college requirements. 

The unitester developed by KELLER itself is used for intermediate and final tests of our pressure transducers and transmitters. The spare parts required for the unitester we are using now are no longer available on the market. Out of this challenge, the Development Department and I defined my task together. The new unitester should consist of several modules which can be combined as desired. As part of my diploma thesis, I decided on the "Insulation and Gas Discharge Module". I then developed this module for KELLER and wrote down my findings and what I had learned during the process.

The module is used to measure the insulation resistance. Typically, this test is carried out with 500V DC to detect leakage currents between two electrical conductors or a housing at an early stage. During the development of the module, I worked out various concepts. The converted module can release a voltage of 50 to 1500 V DC and thus check the insulation resistance. A microcontroller and an RS485 interface with Modbus protocol are used for control. The test voltage is generated with a high-voltage module. A direct connection to 230 V also offers the possibility for stand-alone operations and ensures galvanic isolation from the mains.

Evaluating the parts was not easy, as the market no longer has many materials to offer. Despite the rare market situation, I was able to find and order all the parts required. The coordination and support within the team was flawless. During this intensive study period, I was able to learn and develop enormously. I now know what it means to carry out a project from A to Z.

Many thanks to all who have supported me during this time. The whole development team was a great help. Thanks also go to the Quality Assurance Department, who had to manage without me such a long time.