| 摘要 |
1513200 Underwater telephony EFA ELEKTROFUNKGERATE AG 15 Dec 1976 [17 Dec 1975] 52327/76 Heading G4F In an underwater telephone transmitter two monostable RC multivibrator circuits are interconnected, the microphone electric output is fed into at least one RC circuit to modulate the pulse train frequency, and the modulated pulse train is emitted via a piezo-electric transducer. A pulse-to-sinusoid circuit may precede the transducer. The transducer may be switched to act also as the input transducer of an appropriate receiver. |
