为加强居家安全防范,本文介绍一种能辨别来客身分的音乐门铃。这种门铃能通过不同的门铃声来辨别来客是陌生人还是亲朋好友,其制作容易、成本低廉、动作可靠,具有一定的实用价值。 To enhance home safety precautions, this article presents a music doorbell that distinguishes visitors. This kind of doorbell can tell whether the guest is a stranger or a relative or a friend by using different doorbell tones. The doorbell is easy to manufacture, low in cost, reliable in operation and has certain practical value.