I have reverse engineered a sounder circuit which appears to be using a center tapped inductor. Since then, I have tried to find center tapped / 3-pin inductors and cannot find them from a reliable source, the only place I manage to find was from Huizhou Haicheng Electronics Factory on Alibaba, see below.

three-pin inductor

After some research, I have found that things such as auto-transformers or coupled inductors can also be used in sounder resonating circuits.
As I understand it, the difference between a center tapped inductor and a coupled inductor is that the CT is a single coil around a core with a wire 'tapped' at some point in the middle of the coil, and a coupled inductor is two separate coils sharing a common core, if the end of one of the coils is connected to the beginning of the next, this essentially, at least in my mind, makes a tapped inductor.
Now, it is very easy for me to source coupled inductors from reliable suppliers such as Mouser, Farnell, and RS, etc, so it is much more preferable if I would be able to use these as a replacement.

So the question is: Can coupled inductors be used in place of a tapped inductor?

If yes, what would the advantage be of using one over the other, other than the fact one is much easier to find?

Or am I way off the bat and they are two completely different things?

Thanks in advance.

Side Question:
Would two inductors in series act similarly, or not due to the fact they do not have a common core like the above two components?


1 Answer 1



You are right regarding the fact that connecting two coils of a coupled inductor (transformer) in serie makes a center tapped inductor (autotransformer).

(the words in the parenthesis are the generic terms, while the ones you use are more specific to sound/signal processing)


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.