Your experts in
custom specific
inductive components
since 1973


Outstanding performance in all areas

Spezial-Transformatoren-Stockach GmbH & Co. KG (STS) specialises in the development and manufacture of custom specific inductive components with a high power density, high efficiency and demanding  requirements on insulating and cooling.

STS's transformers and inductors are used in challenging industrial, medical, railway and smart grid applications around the world. All of our custom specific inductive components are designed – according to your specifications and compliant with the relevant standards – on site in Stockach on Lake Constance, where they are then comprehensively tested and produced using a highly efficient lean production process. Thanks to our comprehensive fundamental research and decades of project experience, our transformers and inductors stand the test of time, which means that you can count on them for many years.

Christof Gulden, Managing Director

5 qualified employees
5 % research and development
5 years of experience
5 % made in Germany


We do not compromise on quality

STS is certified pursuant to DIN ISO 9001-2015. The qualities that make us special are reflected in everything we do – from our project-specific advice and customised designs, to our verified material and product quality, on-time delivery and availability thanks to our lean production processes and, lastly, our promise to supply replacement parts until the end of life of your product. These all-embracing quality standards ensure that your applications keep functioning efficiently and reliably for many years to come.


Highly efficient

At STS, we have adopted a continuous improvement approach, which is actively pursued by all employees. Each and every day, we work to improve our products, speed up our development, testing and production processes and further improve our delivery times and productivity. The philosophy and methods underlying lean management and lean production are firmly established in our corporate strategy. We are also increasingly taking advantage of the digitalisation opportunities at our fingertips to create paperless value-added processes. With all of these steps we have one goal in mind: providing a quicker, more cost-effective service to you!


Commitment to environmental protection

We are not exaggerating when we say that STS is a model company when it comes to energy-efficiency. For example, we use a highly efficient heat recovery system for our ventilation and compressed air supply systems. All of the electricity we use comes from renewable energy, of which 20 % is generated from our on-site photovoltaic installation. Our LED lighting, which is activated by movement, saves electricity every day. This has allowed us to reduce our energy consumption by 25 %, despite our continuous company growth. The German Federal Office of Economics and Export Control (BAFA) has supported our energy-efficiency approach. We also actively work to protect the environment by taking steps to extensively reduce and recycle our waste. Moreover, our manufacturing practices are in line with RoHS and REACH guidelines.


Our inductive milestones

STS first gained its outstanding global reputation as a leading manufacturer of custom specific inductive components back in 1973. We are growing continuously, and taking steps to ensure that our success story continues.


50 years of STS in Stockach - a success story Made in Germany! Today, STS employs around 190 people and is a globally successful, growing company.




Average organic revenues growth of 11 % p.a. over the last 4 years.


New building at factory I in the industrial area of Hardt in Stockach. The production area is extended to 5,000 m2 and factory II is moved from Krumbach to Stockach.


New, platform-based choke concept for power inductors is introduced onto the market: INDUR


STS takes steps to optimise its processes: Lean production and lean management approaches are introduced.


Factory II is founded in Krumbach with a production area of 2,000 m2.


Revenues double within the last 5 years - flexible infrastucture adoptation is needed.


Christof Gulden becomes managing director. Annual strategie meeting: STS decides to work on selected industries.


Sales volume doubled within the last 3 years. The production area is extended from 1,000 m2 to 2,000 m2.


Christof Gulden starts working at STS. Establishing engeeniring department to focus on custom specific components for our customers. 


The production area is expanded to support the company’s continuous growth. A new production area with offices spanning a total area of 1,500 m2 is built in the industrial area of Hardt in Stockach.


Company taken over by new shareholders.  Max Gulden becomes managing director.


New building at Industriestraße 14 spanning a total area of 400 m2.


Company founded by Schenk and Thieler in the “Am Stadtwall” offices in Stockach.




We are here
to help

Would you like to find out more about STS and our custom inductors? Simply get in touch! We would be happy to advise you on your application.