Sunday, June 24, 2018
Publication Date: 06/1/2008
Archive >  June 2008 Issue >  New Products > 

EPCOS Intros New Current Sense Transformers
Current-sensing transformers.
Iselin, NJ — EPCOS has developed two series of current sense transformers that are particularly suitable for compact DC/DC converters because of their SMT design. These transformers are a complete solution with the primary winding already integrated. The first series is a comparable solution for existing designs based on an EE5 core. The second was developed as a miniature variant with a much more compact E4.2 core.

In addition, the primary winding is not implemented on an external bracket as in the EE5 series but in a space-saving design integrated in the coil former.

Current sense transformers can only be used to measure AC. The measured current flows via the primary winding of a transformer, and a voltage signal proportional to the current is detected on the secondary side. This technology combines the advantage of low losses with reliability, ruggedness and easy implementation.

Current sense transformers are used wherever control, protection or load-detection functions are required. Typical applications are compact DC/DC with mid-range outputs.

With the EE4.2 series, the DC resistance of the primary winding is 2.5mΩ for all types at a rated current of 7A, and the test voltage is 360VAC. With the EE5 series, the DC resistance of the primary winding is 0.8mΩ for all types, at a rated current of 20A, and the test voltage is 500VAC.

Contact: EPCOS, Inc., 186 Wood Ave. South, Iselin, NJ 08830 800-888-7728 or 732-906-4395 fax: 732-632-2830 Web: or

search login