Drop voltage of a doorbell transformer
Best solution - replace the power source to get the desired voltage.

If you can't replace the power source for some reason, add another transformer in between.

There is another theoretical &quot;hard way&quot; - remove some wire turns from the secondary winding of the existing transformer. However, this is not a good idea for many reasons:



may be unreliable or even dangerous if not done properly
knowledge needed of how to disassemble the transformer
even if done decently, will be most likely time consuming and thus expensive