Your potential is our passion.

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Kohsel is a Scandinavian supplier of customized transformer solutions for customers all over the world. Our mission is to unleash your full potential in transformer design.

We are headquartered in Denmark and have our own business and production sites across Europe and Asia. With +500 employees and 50 years of experience, we deliver high-quality transformers with built-in know-how.

Rectangular wire

Rectangular wire provides compact windings with better electrical efficiency, high performance and low cost. Kohsel has many years of experience with supplying transformers and chokes with rectangular wire.

Foil winding

Kohsel has wide experience with effective foil winding which increases reliability, reduces size and weight, improves electrical efficiency and saves energy. We have supplied 3-phase transformers and chokes on a large scale for many years.

Helical winding (Edge winding)

A helical winding is a rectangular wire wound in a helix shape. Kohsel design the winding tool required for the helically wound inductor.


Potting protects transformers from moisture, corrosive chemicals, vibration and other tough operating conditions. Kohsel has many years’ experience with potting and vacuum techniques.

Quality control

Kohsel ensure high quality through a constant focus on safety, cutting-edge production methods and training. Final control focuses especially on the critical tolerances that are important for the customer.


Encapsulation protects your coil from moisture, corrosive chemicals, vibration and other tough operating conditions. Encapsulation is a complex process that requires experience, product knowledge and structured production processes.


All our transformers go through a transformer varnish impregnation process. Kohsel has many years of experience with varnish impregnation.

Design process

Kohsel uses cutting-edge technology in the design phase. Our engineers have wide experience with 3D simulation software. We work closely with our customers and take the necessary time to satisfy our customers’ wishes and requirements.


At Kohsel we ensure that our customers’ products are protected during shipping and that the products are easy for the customer to unpack. We involve our customers in developing the ideal packaging solution.