| 摘要 |
<p>The amplifier circuit receives the signals emitted or transmitted by a telephone, enabling several people to take part in the telephone conversation. Switching between the modes of operation is achieved by a logic counter which blocks or frees the lines of amplification. This may be mechanically or electrically controlled, or operated by the effect of sound information received over a given sound intensity. The switch comprises two bistable flip-flops having three stable states, allowing amplification of the received signal, establishing a conversation between several speakers, or transmission of signals to a remote station.</p> |
