一、原理 振铃电路是电话机中的一个重要组成部分,它将交换机送来的振铃信号转换成声音信号并发出。我国目前普遍采用的振铃信号为频率25Hz、峰—峰电压90V的交流信号,时间间隔为送1秒、停4秒。振铃电路按其结构一般可分为三种:极化铃振铃器、压电振铃器和集成振铃器。 1.极化铃振铃器 极化铃即交流电磁铃,它一般由线 First, the principle Ringing circuit is an important part of the phone, it will switch the ring signal is converted to voice signals and issued. The ringing signal commonly used in our country is the AC signal with the frequency of 25Hz and the peak-to-peak voltage of 90V. The time interval is 1 second and 4 seconds stop. Ringing circuit according to its structure can be divided into three general: polarization bell ringer, piezoelectric ringer and integrated ringer. 1. Polarize bell ringer Polarize is the exchange of electromagnetic bell, it is generally by the line