公开(公告)号：US4367375A

公开(公告)日：1983-01-04

申请号：US186579

申请日：1980-09-12

申请人： Yuuji Tsuruga ,  Akihiro Kobayashi ,  Makoto Yoshitoshi ,  Yutaka Nishino

发明人： Yuuji Tsuruga ,  Akihiro Kobayashi ,  Makoto Yoshitoshi ,  Yutaka Nishino

IPC分类号： H04M1/76 ,  H04M1/50 ,  H04M1/00

CPC分类号： H04M1/50

摘要： A push-button dial circuit having a low DC resistance and a high output impedance. An oscillator for generating a multi-tone dial signal is connected through a buffer transistor to terminals for coupling the multi-tone dial signal to a subscriber's line. The terminals also supply a DC power source current to the dial circuit. A constant voltage circuit is connected to the oscillator to stabilize the DC current supplied to the oscillator, and a reactance transistor circuit is connected between the terminals and the oscillator for defining a DC supply path from the terminals through the reactance transistor circuit to the oscillator. The reactance transistor circuit includes a transistor having a capacitor and a resistor respectfully connected across the base-emitter path and across the base-collector path of the transistor.

摘要翻译： 具有低直流电阻和高输出阻抗的按钮拨号电路。 用于产生多音调拨号信号的振荡器通过缓冲晶体管连接到用于将多音调拨号信号耦合到用户线路的终端。 端子还向拨号电路提供直流电源电流。 恒压电路连接到振荡器以稳定提供给振荡器的直流电流，并且电抗晶体管电路连接在端子和振荡器之间，用于定义从端子通过电抗晶体管电路到振荡器的直流电源路径。 电抗晶体管电路包括具有电容器和电阻器的晶体管，该电容器和电阻器横跨基极 - 发射极路径跨过晶体管的基极 - 集电极路径。