Zoomed In The electric airbag

Editor: Stefanie Michel

Once upon a time in Mannheim, in the 19th century..– that could be the start of the story of Stotz-Kontakt – and also the story of Karl Drais and the bicycle, Carl Benz and the automobile as well as the emergence of the present TÜV. But it starts with the rise of electrical engineering or with the installation of electric light in more and more buildings.

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Stotz developed a switch that protected from overload and short circuit.
Stotz developed a switch that protected from overload and short circuit.
(Source: ABB Stotz-Kontakt)

It had only been 10 years since Thomas Edison had invented the electric bulb, when Hugo Stotz established the company "Moyé und Stotz, elektr. Installationen" in 1891 in Mannheim, with his partner Moyé. With this company, Stotz converted, for example, petroleum and gas lamps for electrical operations and built blocking stations to supply to individual houses. He also devised lamps, switches, sockets and fuses. The company became "Stotz und Cie. Elektrizitätsgesellschaft mbH" after the partners parted ways in 1896. Thanks to progressive electrification, the business was so successful that Stotz shifted to Mannheim in 1901. Such a relocation had to be publicised – with a neon sign on the roof, the supposedly first neon sign in Germany.

Protection from overload

In the meantime, a lot of experience was gained in electrical installations that the company then decided to also offer installation materials from its in-house production. This contributed to the steady growth of the company. Branches came up in Freiburg im Breisgau, Karlsruhe, Worms, Schlettstadt, Heidelberg, Pirmasens, Wiesloch, Stuttgart and Kaiserslautern. 300 technicians were employed. That was in 1912 – the year in which Stotz sold this installation division to Brown, Boveri & Cie (BBC) and renamed his company "Stotz und Cie. GmbH – Fabrik elektrischer Spezialapparate".

For this company, a large production plant was set up in 1913 in Mannheim-Neckarau for producing components for the electrical installations. However, the first world war halted this growth. Things got into a way that Stotz had to sell his plant and his company to BBC at the end of the war. But the company name remained the same and he himself remained as the managing director of the subsidiary. This arrangement was successful because the plant manufactured first class components.

The most significant development, which is still mentioned with Stotz in one breath, started in 1923, when the inventor was searching for a solution to be able to supply electrical energy to houses in a safe and simple manner. A switch was made, which protected overloading and short circuits – the first circuit breaker with thermal-magnetic trigger. Stolz named Uwe Laudenklos as managing director of the present ABB Stotz-Kontakt GmbH and this invention the "Airbag of electrical engineering".

In particular, as compared to the fuses, this Stotz-Automat could simply be switched on again. The invention was patented in 1924 and was advertised by BBC. The emphasis was that the automat was only a one-time purchase as it replaced connected costs, inconveniences and operational disorders would be avoided. The manual series production of the circuit breakers started in 1928.