EXPERT - water-cooled transformers and inductors

EXPERT Transformatorenbau GmbH, based in Lorsch in southern Hesse, has over 50 years of tradition and experience in the construction of water-cooled high-current transformers, rectifiers and chokes.

You benefit from over 50 years of tradition and experience

The technical and technological "know-how" that has grown over many years, combined with the inventiveness and craftsmanship of our employees, is the basis for the extraordinary quality and reliability of our products. We offer components for high-current applications in the DC and AC range.

In addition to standard applications, our company specialises in individual support for customer requirements in conjunction with cost-efficient solutions. The task-specific design of transformers and inductive components is very important to us in order to achieve an optimal and cost-efficient result.

The characteristic feature of EXPERT components is the water cooling. The welding power sources developed and manufactured for the automotive industry for resistance welding technology have always set standards for the technical level of development and form the basis for international standards.

Our products have also been used for many years for annealing, melting and heating processes in the glass, ceramics and semiconductor industries. In recent years, extensive know-how in the field of conductive and inductive heating of metals for heat treatment has been developed together with universities and partner companies.

EXPERT can ensure a worldwide presence and customer support through partner companies and independent representatives.

The future is electric and characterised by renewable energies. The transmission of even high power requires compact and thus resource-saving solutions, which are made possible by water-cooled components. Our goal is to make our contribution with decades of experience in this field.

Our history


Foundation of EXPERT Maschinenbau GmbH in Lorsch by Hans Jäger with participation of EXPERT Inc. based in Detroit / USA . Production of rotary tables and other mechanical components for the automotive industry.


Development and manufacture of the first transformers for resistance welding.


EXPERT Maschinenbau GmbH is, among other things, the market leader in the field of transformers for resistance welding in Europe. The standards in this market segment are decisively determined.

Start of the development of new types of medium-frequency transformers for the high-current range.


Medium-frequency technology begins its triumphant advance as the dominant welding process in the automotive industry.

EXPERT Maschinenbau GmbH becomes market leader in MF welding transformers.

The development and manufacture of process transformers for high-energy processes in the glass, ceramics and semiconductor industries is expanded.


Spin-off of the product area transformers as an independent company within the framework of an MBO with the new company name Expert Transformatorenbau GmbH.


Move to new building with office wing and production facility.


Expert Transformatorenbau GmbH has established itself as one of the leading market players in the field of high-current transformers worldwide and supplies numerous customers with series products, replacement solutions, individual and special designs.

Main activities are in the automotive sector, for heating applications and special solutions in the industrial environment.