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现在广泛使用的按键电子电话机,其振铃(收信)电路一般均采用电子铃专用集成电路作为核心。在家庭、办公室、写字楼等较安静环境中使用,其铃声使人感到清脆悦耳,音量足够;但在工矿企业的生产现场或其它噪声大的环境中,令用户无法听见振铃声。为此,我们在TCL868(5)P/T型按键电子电话机振铃电路中(见附图)增加了一个增音器,使话机铃声增大到足够宏亮、清晰,满足了生产现场的要求。 1.工作原理把增音器的插头插入插座后,原电话机内输出变压器T301二次侧3端与机内扬声器B断开,不工作。此时,若对方摘机拨号后,本机振铃电路便工作,由T301输出的音频信号不再经机内B发声,而输出
Now widely used key telephone, the ringing (receiving) circuit are generally used electronic bell special integrated circuit as the core. Used in quiet environments such as home, office and office building, the ringtones make people feel crisp and sweet with enough volume; however, the ringing sound can not be heard in industrial and mining enterprises’ production sites or in other noisy environments. For this reason, we have added a repeater in the ringing circuit of TCL868 (5) P / T key telephone electronic telephone (see the attached figure), which makes the ringtone of the telephone increase enough to be loud and clear and meet the requirements of the production site Claim. 1. Working principle Put the plug of the repeater into the socket, the original output end of the transformer T301 3 side of the secondary side of the transformer is disconnected from the built-in loudspeaker B, does not work. At this point, if the other off-hook dialing, the local ring circuit will work, the audio signal output by the T301 is no longer within the machine B sound, and the output