100 years ago, Dr. Bernhard Jansen filed a patent for the high-speed resistor-type tap-changer. This invention made it possible for the first time to switch transformers under load, thereby enabling widespread electricity supply.
The inventor
Who was the brilliant mind behind this revolutionary idea? Dr. Bernhard Jansen, born on 31 August 1899, in Wissen an der Sieg, began studying mechanical and electrical engineering at the Technical University of Hannover in 1919, and began his career at the Hannover Power Plant. In 1928, Jansen became a member of the board of Oberpfalzwerke in Regensburg, which he transformed into a modern energy supplier. To mark the anniversary, we’re using artificial intelligence to have the brilliant inventor talk about his invention in a podcast.

Listen to the podcast with Dr. Bernhard Jansen here.
The patent story

On 13 July 1926 – at the age of just 27 – Dr. Bernhard Jansen submitted his idea to the Reich Patent Office in Berlin. The invention of the so-called high-speed resistor-type tap-changer solved a problem that was troubling many energy suppliers at the time: regulating transformers under load to keep the voltage stable. It was only through this idea that it became possible to create power grids as we know them today. The basic principle of the invention remains the same to this day. In total, Dr. Jansen held 49 German patents dealing with improvements and further developments related to the tap changer.
Learn more about the story behind this ingenious invention.
Made by Reinhausen
When Dr. Bernhard Jansen set out to build the first prototype of his invention in 1929, he faced a problem: he couldn’t find a workshop that could manufacture a crucial component – a special gear for the transmission. After a long search, Jansen found a workshop in the Reinhausen district of Regensburg that manufactured the component for him in just one day. The name of the company: Maschinenfabrik Reinhausen. The beginning of a success story! Today, the small workshop has grown into a globally active family-owned company that has continuously refined this ingenious invention over the years and is leading it into the future under the “Made by Reinhausen” label.

More history
… and stories that bring the anniversary to life and offer inspiring ideas that bring the anniversary to life and offer inspiring ideas for the energy supply of the future can be found on Reinhausen’s anniversary for the energy supply of the future can be found on Reinhausen’s anniversary website.


