改脉冲话机为音频话机曹虎成展起来的。二者唯一的区别就是拨号电路中的发号方式不同。所以，只要将脉冲话机中的脉冲拨号电路改为音律拨号电路，即可方便地将脉冲话机改为音频话机。音频发号电路多采用中规模集成电路，尽管不同型号的话机采用的拨号电路不同，但各电路的... Change the pulse phone for the audio phone Caozhao Cheng up. The only difference between the two is the way the dialing number is different. Therefore, as long as the pulse of the pulse dialing circuit to the dial tone circuit, you can easily change the pulse phone to audio phone. Audio frequency identification circuit and more use of large-scale integrated circuits, although different types of phones using different dial-up circuit, but the circuit ...