| 摘要 |
PURPOSE:To realize a two-way communication with high output and to attain simultaneous talking depending only on a speaker such as loudspeaker telephone, interphone and two-way TV by replacing a communication line having a complicated impedance characteristic into a proper resistor so as to attain balancing. CONSTITUTION:A transmission signal generated in resistors R1, R2 of a signal discrimination transistor (TR)1 with diodes D1, D2 is at opposite phase completely over an ultra wide band and no transmission signal is leaked to a neutralizing point B formed by neutralizing resistors R3, R4. Then a reception signal received from a transmission/reception line T1 is fed to an output TR2, and given to the base and emitter via a resistor R5. Since a collector current multiplied by a current amplifier factor hfe is given superimposingly at the same time, the resistor R5 is decreased apparently and the received signal is extracted largely between the base and emitter by the share. Since the TR1 directly coupled to the TR2 is excited from the emitter to the base, a common mode reception signal is generated in the resistor R1 and the reception signal is extracted at the neutralizing point B without neutralization. |
