多功能电子门铃崔鑫生本文介绍的多功能电子门铃具有以下功能：主人在家时，通知主人有客人来到；主人不在家时，告诉客人主人不在；主人有事外出一会时，告诉客人稍候。工作原理多功能电子门铃采用３个音乐集成块（Ａ１－Ａ３），其工作原理如图所示。图中，Ａ１中固化通... Multifunctional electronic doorbell Cui Xinsheng This article describes the multifunctional electronic doorbell has the following features: When the owner at home, notify the owner of a guest came; the owner is not at home, tell the owner is not; the host something out for a while, tell the guests later. How it works Multifunctional electronic doorbell with 3 music blocks (A1-A3), its working principle as shown. Figure, A1 curing pass ...