Replicate transformer made from inductor

The item is a coilcraft component 143-11J12L but a former engineer wrapped it with a secondary wire that I’m told changes it from a inductor to a transformer. That engineer is long gone and we don’t really know the purpose or how to replace it.

Can anyone help me understand this and replace it?


Hello spaisner, welcome to the DigiKey TechForum.
I’m not an engineer, and I do not know why the wire was wrapped around the inductor.
If you have some information on the design, or a copy of the schematic, maybe one of the engineers may be able to help with this.

Welcome to the forum.

Yes, that is an inductor modified into a simple transformer.

Given the simple additional 2 turn winding I suspect the performance characteristics aren’t very critical.

So simply starting with a new Coilcraft part and duplicating the extra winding based on how it looks might work.

The wire you want to use is a special purpose type named magnet wire (first used for electromagnets).

Here’s the Digi-Key options:

If that doesn’t work you’ll need the schematic diagram for the circuit.

If you don’t have the schematic, then you’ll need to create one by reverse engineering the circuit. (which won’t be difficult based on component density shown in the photo)