| 摘要 |
<p>1. Circuit arrangement for connecting a transmission device (UB) of a modem to a telephone line (FL), wherein the transmission device (UB) generates or receives, as the case may be, data signals (D) assigned to the data to be transmitted and received, and wherein the operating voltage (UV) of the modem is produced from the loop current of the telephone line (FL) using a regulating stage (R), and wherein dialling pulses are produced by means of interruptions of the telephone line (FL) via a switch (nsi), characterised in that there is provided a frequency separating filter (F) which on the one hand is connected to the telephone line (FL) and on the other hand to the regulating stage (R) and to the transmission unit (UB) and which establishes a connection between the telephone line (FL) and the transmission device (UB) that is D.C. isolated and permeable to the data signals (D), and which frequency separating filter establishes a D.C. connection between the telephone line (FL) and the regulating stage (R) which is permeable to the dialling pulses and blocks the data signals (D).</p> |
