本文介绍的对讲电话时用于家庭中楼上楼下对讲或屋内与院门外的对讲。该机语言清晰,音量大,无需手持,使用时只要按一下启动键,讲完后按一下关闭键便可。平时不耗电,讲话时指示灯随语音闪烁,既好玩,又有一定的实用价值。所用都是普通元件,制作容易。电路加附图。工作原理:图中,上虚线框内为甲机电路,下虚线框内为乙机电路,中间为“总机”——公用部分。甲、乙机电路完全相同。复合管BG1、BG2用于甲机放大,BG3、BG4用于乙机放大。R1、R2分别为两对复合管的下偏置电阻,微型话筒M1和M2又兼作复合管的上 This article describes the intercom phone for upstairs and downstairs in the family intercom or outside the house intercom and intercom. The aircraft language is clear, the volume is large, no hand-held, when you use just press the start button, after the finish press the close button. Usually does not consume electricity, when the speech light flashes with the voice, both fun, but also a certain degree of practical value. Used are ordinary components, easy to make. Circuit plus drawings. The working principle: In the picture, the upper dashed box is the circuit of a machine, the lower dashed box is the circuit of B, the middle is “switchboard” - common part. A, B circuit exactly the same. Composite pipe BG1, BG2 for a machine to enlarge, BG3, BG4 for the B machine to enlarge. R1, R2, respectively, for the next two pairs of composite tube bias resistance, microphones M1 and M2 also double as a composite tube