| 摘要 |
338,591. Electroacustic Ges. Oct. 4, 1928, [Convention date]. Subaqueous - sound signals. - A subaqueous alternating - current - operated sound signalling installation using the same oscillators 14, 15, 16 for transmitting 'and receiving is provided with a switch 12 which, on being moved from the transmit to the receive portion, moves simultaneously the switch arm 20. This completes the circuit of the relay 18 to open the switch 17, thus breaking the leads 23 at a point between the change-over switch 12 and the continuously running A.C. generator 2, and near to the latter to prevent mutual induction between the transmitting and receiving circuits in the same room B during reception.
|
