| 摘要 |
<p>PURPOSE:To realize an economical circuit and to enable the amplification of the communication signal simply, by using a transistor circuit in place of a choke coil. CONSTITUTION:The resistors R1, R2, R1', R2', flowing the communication current are connected in series with the incoming and outgoing lines, and the bases of the transistors Q, Q' are connected to the communication line of the series circuit and the collectors are to the power supply circuit. The impedance viewed from the line is as shown in equation. Taking the resistors R1, R2 as 100 ohms and R4 as 10 ohms, the resultant resistance is 1.2 kohms, then the value is enough to block the communication signal.</p> |
