We have a portable small toy which we want to make a sound on it when is connected to socket. I don't know if we must use a little speaker with a magnet or maybe we can make a noise with a mechanical object (like a beat on a very small bell). It must be as cheap and small as possible. Thank you and sorry for this noob question.
Electronic – What’s cheapest way to make a sound
sound
Best Answer
A piezo speaker (Piezoelectric Transducer) is most likely what your looking for. They are quite cheap, usually around $1, and small! There are also many other alternatives, take a look at Loudspeaker Drivers Wiki.
You could even try to make your own, not that I would recommend it. How to make your own piezoelectric speaker.