Clip¹⁾, clasp²⁾, clamp³⁾ or spring⁴⁾ - a part in an electronic transformer used for holding together or providing mechanical support for the magnetic core and bobbin. Often made from stainless steel.⁵⁾ Because of significant mechanical force exerted by the clips they can be used in almost any orientation (horizontal, vertical).

Clips in EFD25 transformer

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

Clips in EFD25 transformer (assembled)

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

Depending on the size and shape of the magnetic core, as well as the bobbin the clip can have various designs, even for the same type of ferrite core. For instance, the clips for ETD49 supplied by Ferroxcube are designed to clip onto the bobbin and push each half of the core towards inside of the bobbin. As a result both core halves are pressed together and at the same time secured to the bobbin.⁶⁾ On the other hand, ETD44 clips supplied by Norwe exert the force only on the core, but not on the bobbin. ⁷⁾ This can be an advantage, but also a disadvantage, for instance when the design is exposed to vibrations, and a core which is loosely fitted in the bobbin would be prone to cracking.

Some clips also perform additional functions. For instance clips for small RM cores can comprise additional pins to be soldered into the PCB (e.g. for connecting to ground of the electrical circuit), and clips of small flat transformers (e.g. EFD10) have a flat top, so that a suction nozzle of an SMD placement machine has a flat surface to pick the component with.

Clips (from top): E42, ETD44 (Norwe), ETD44 (Ferroxcube), ER14.5, RM8, EFD10

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

Clips in ETD29 transformer (assembled)

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

Clips in ETD29 transformer

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

Clip with a flat top in an EFD10 transformer, suitable for SMD placement

^{S. Zurek, E-Magnetica.pl, CC-BY-4.0}

• ferrite core
• bobbin