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Eddy current retarders for dynamometers

HomeEddy current retarders for dynamometers

We are the worldwide reference brand in eddy current retarders known as power absorber units for any type of power dynos. Most manufacturers choose the FRENELSA brand for its reliability, safety and repeatability to carry out their tests. More than 50 years of experience support us.

Adaptation and customization

We manufacture a wide range of retarders to carry out any type of test, fully adapted to the needs of each customer.

Long shafts

We manufacture long shafts tailored to each customer, both in length and in diameter and design, with splines, keyways, holes, etc.

Eddy current retarders for dynamometers


For all types of voltages: 12V, 24V, 36V, 48V, 72V, 96V, 192V and the possibility of installing temperature probes for monitoring and control.

Eddy current retarders for dynamometers


Eddy current retarders for dynamometers
Chassis dyno
Eddy current retarders for dynamometers
Engine/Transmission dyno
Eddy current retarders for dynamometers
Towing dyno
Eddy current retarders for dynamometers
Hub dyno
Eddy current retarders for dynamometers
Agricultural dyno

Why a Frenelsa retarder?


Pioneers in launching to the market the trough shaft option adapted to the needs of the client.

Manufacturing process and control

We ensure the best performance characteristics during the tests.

Without intermediaries

We offer the best product on the market at an adjusted cost.

Personalization and advice

Choice of the most suitable model from our range of retarders, adapting it to the customer’s needs.


Complete manufacturing in our plant allows us to offer the best delivery times.

Logistics service

Management of transport, customs, documentation, insurance… until delivery to the customer.

Success stories

Inertia rotor

Electromagnetic brake design with flywheels for emission dyno.
Inertia rotor
Extra-long shaft

Extra-long shaft

Brake solution with an extra-long shaft to optimize the installation in high power cars dynamometer.

Series brakes

Installation of several brakes in series for severe application in towing trailers on the highway.
Series brakes


What type of current does it work with?

Direct Current.

How is it controlled?

It is controlled by varying the applied voltage.

Can it work continuously?

Yes. As long as the sizing is adequate.

Does it suffer any wear?

No. Being electromagnetic brakes, there is no friction or wear.

Does it need maintenance?

Our brakes do not require maintenance, because we use top quality bearings with high-performance greases.

What advantages does it have over other systems?
  • Quickly reaches the requested torque.
  • High torque at low revs.
  • Easy to control via PC.
  • Allows simulation tests to be carried out.
  • Simple and economical installation.
Does FRENELSA help me with transportation, customs, insurance, etc.?

We ship our products all over the world and we have extensive experience in all transport, customs and insurance procedures. Our commercial department is in charge of the entire process until the products arrive at the customer’s home.


Request quotation

Provide us with the details of your application and we will recommend the solution that best suits your needs.